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Electrification is a growing force within the transportation sector, with more e-bikes and electric vehicles launching every year. This change is being driven by multiple forces such as government initiatives for greener transportation, industry innovation to find more sustainable solutions and consumers growing more conscientious of their environmental footprint. Alex Stern, Senior Industry Strategy Manager Automotive at Autodesk gives MTD magazine his perspective.

In a bid to reduce CO2 emission levels, governments are moving to ban internal combustion (IC) engines, which currently account for 40% of oil consumption in Europe. Sales of new IC engines will be discontinued from 2040 in the UK and France; possibly even earlier than that, with more emphasis being placed on EV. In the UK specifically, the use or purchase of EVs are also being heavily incentivised to drive adoption. Here are three of the approaches transforming how the automotive manufacturing industry is making electric vehicles and the resulting environmental benefits.

A new approach to power

To cope with EV demand, within the next three years we’ll need the UK to launch its first full-scale Gigafactory for battery production. This is according to the Harwell-based Faraday Institution, a research institute backed by the government to ensure a steady supply of batteries in the future. However, simply replacing oil with electric batteries isn’t enough to lower emissions. The electrification of the automotive industry will require advanced manufacturing methods to change different aspects of the car, from the engine to the weight and also the battery.

At present, the biggest challenge is the battery and the vehicle architecture. Manufacturers need to integrate the battery and produce a car that enables the battery to be as powerful as possible - both in the most cost-efficient way. Battery cost is predicted to fall as production capabilities increase, but this will require funding for at least eight full-sized Gigafactories to be built over the next 20 years. Manufacturers will need to save costs in other parts of the production process to afford these investments. 

One way to reduce cost is related to how engines are put together. IC engines are currently cast in metal, which is then milled and drilled in two or three sections and joined together. Electric motors have fewer parts than IC engines. They are lighter, less complex, and have lower stresses on the materials. This opens up new process opportunities for the use of lighter materials, for less energy-intensive production and for the adoption of different techniques, including additive manufacturing or 3D printing.

Additive manufacturing can dispense with conventional tooling, as minimal machining is required. Parts to integrate into an electric battery can be produced as needed, removing expensive inventory and lowering costs. They can also incorporate design upgrades, as they are developed without waiting for the next model cycle.

Multi-material printing capabilities provide opportunities for innovative end products, made of multiple materials that become part of each other. Sensors, batteries, electronics and microelectromechanical systems (MEMS) can also be embedded directly into components.

Sustainability: Consumption and recycling materials

Sustainability applies as much to manufacturing processes as to materials. When building electric vehicles, there will be a growing focus on recycling, recyclability and closed loop manufacturing.

The European Union’s End-of-Life Vehicle (ELV) Directive 2000/53/EC sets recovery targets for recycling of vehicles and components, encourages manufacturers to design their vehicles with part reuse and recycling in mind, and restricts the use of certain heavy metals in new vehicle manufacturing processes. In the case of some plastics such as polyethylene terephthalate (PET), a commonly recyclable plastic resin, recycling of RPET (recycled plastic bottles) has been found to use 70% less energy than virgin fibre production. Elsewhere, additive manufacturing can save as much as 94% of the material by using Rapid Deposition Process (RDP), instead of conventional billet milling and fabrication.

Sustainability will increasingly be fed and guided by data. Sensors embedded in cars and factories now capture the physical properties and behaviours of objects and extract useful data from them. ‘Digital twins’ can virtually replicate production processes and collect information from products during simulation; designers incorporate this knowledge to improve and modify products, even during lifecycles.

We’re already seeing this being put into practice. For example, Jaguar Land Rover is designing vehicles that recycle aluminium from old cars to manufacture new cars. The development for the second phase of the ‘closed-loop strategy’ has begun with pre-production of Jaguar iPace SUVs destined to be scrapped. Once the batteries have been removed and either recycled or placed into a ‘second life’, sensors in the advanced scrap process identify aluminium, which is then recovered and reformed to produce new cars.

Weight and see: exploring generative design

The engine is the heaviest item in an IC-powered vehicle; in the case of electric vehicles, it’s the battery. The bigger the battery, the more power and the longer the range or higher the speed. The relationship between weight and range/power is even more impactful in electric cars than in IC vehicles. Small weight savings can make a big difference in performance.

Any weight saving can be used to increase the size of the battery and subsequently, car performance. Materials are inevitably the first thing considered when it comes to reducing weight – and improving overall vehicle performance and through-life costs.

Furthermore, ‘lightweighting’ can be achieved by either switching to a lighter material or by reducing the amount of material used in the design. The generative design gives vehicle manufacturers a proven way to improve fuel economy by replacing components with a variety of lightweight, recyclable materials, such as aluminium, magnesium, or PLA plastics. It also enables manufacturers to consolidate components into fewer parts. The generative design gives vehicle manufacturers a proven way to improve fuel economy by replacing components with a variety of lightweight materials, including aluminium, magnesium, high-strength steel, plastics and CFRP. 3D printing can also be used to produce lightweight components, personalised components for mass customisation and on-demand prototypes for generatively designed parts.

Electric motors do not just permit different car layouts, they require them. The shape of battery packs – long, wide and flat – facilitate designs with a lower centre of gravity and allow designers to spread the weight across the car’s structure rather more than is the case with IC powered vehicles, where the weight of the engine is in one specific place. This means that load-bearing structures may not have to carry as much weight, making them lighter. This lighter structure means that more weight can be used in a heavier, more powerful battery.

Closing thoughts

The opportunity to use different materials and techniques will revolutionise EV production. Different materials or compositions will continue to be used in the structure of electric cars.  Advancing technologies in additive manufacturing will permit larger printed structures to reduce weight and increase the power of batteries.

Recycling techniques will continue to increase in maturity, while new light-weighting approaches through generative design will be pivotal to improving power consumption and the range of electric vehicles as an essential design tool in optimising weight, shapes and structures. Additive manufacturing has the potential to become more widely adopted as its capacity to produce high volume parts increases, its cycle time reduces and costs fall.

Electrification is already playing a pivotal role in accelerating innovation in the car industry and automotive manufacturers are being supported by the government, consumers and the wider industry to continue driving this change.

This is the third and final instalment of a three-part article that started back in May to discuss metrology skills. We have looked at how measurement is your business intelligence agency, giving you data on your process and quality to make crucial production decisions. But what if your measurement is feeding you bad data, a ‘fifth columnist’ disrupting and destabilising you. Ian Wilcox reports.

In the previous two articles, I put forward what I believe are three key considerations to control your measurement, enabling cost-effective measurement and giving confidence in your data. By looking at how you manage these considerations and if needed, improve them, you will have started your journey in managing metrology effectively within a business and getting it working for you. This will help you to improve productivity and quality.

Each element is important, but like a three-legged stool, if one leg fails, it will bring the other two down, no matter how strong they are.   

1. Performance/Capability

Metrology offers various methods to check your current measurement capability, giving you data to either provide confidence in your measurement results or at least warn that improvement is required. One such method is Gauge Repeatability and Reliability (GR&R). This common tool is one of many available within Measurement Systems Analysis (MSA).

2. Process/Precision

Understand your measurement processes and what may cause variation within them. Treat them as you would any process within your business andlook to control and improve them. Implement internal common practice and procedures to mitigate any unacceptable levels of variation. Without full automation, not everything can be a fixed, codified procedure. The balance is between people skills and procedures, and is often a fine one. Even automation does not eradicate skill, it just pushes it to the planning stage. 

3. Calibration/Accuracy

No company is an island. You will either be a supplier or rely on a supply chain beneath you, most likely you will have both. To connect yourself to the required standardised world of defined measurement units and traceable measurement, we use calibration and its traceability chain to certify your measuring equipment, providing the link to internationally defined units such as the Metre.

Metrology Skills

Skills in metrology are numerous, how effectively they are deployed is often inextricably impacted, by the level of awareness within a business regarding the opportunities that good metrology can realise. Is measurement a necessary but unproductive sideshow to production; there to tick a customer box? Or do you wish to use the data that measurement gives you to drive competitive productivity and quality. We all know what we know, without an external stimulus and new knowledge, how can we ever grow and enhance capability. Any drive for improvement will face competitive reality, usually meaning that budgetary constraints also apply. Whatever you do, it must pay for itself - generally over ever shorter periods.

With metrology skill, we can split this into the functional application of measurement (by a measurer) and the application of supporting metrology (by a metrologist). A measurer can be anyone who collects production-related measurements within the business, and a metrologist being a person who supports measurement planning, correct application and problem solves measurement processes.

A critical foundation skill required by both is understanding the causes of variation in any measurement process. The causes differ for each measurement process which creates its unique blend of causes, creating an effect that needs to be recognised, understood, and managed as generic groups or singular cases. I have discussed this more in part 1 of the article published in May.

Metrology like a lot of industrial processes is not an on/off switch. It is complex layers of cause and effect that you progress through. Often for every question investigated and resolved, the next layer of optional questions is exposed. However, the rewards are that as each layer is peeled away, it leads to a better understanding and therefore unlocks the next level of productivity and new opportunities for further continuous improvement. Competitiveness in production comes from removing waste and increasing productivity.

Knowing what skills you need is a challenge. When embarking on metrology improvement; materials, measurement environment, and the technologies utilised differ from company to company, making for varied demands for required skills. Basic engineering skills topped up with relevant metrology skills will give you the right individuals to deliver effective measurement.

Some skills such as reading technical drawings and its GD&T are fundamental to all those in dimensional measurement. As is understanding how your actions when measuring can impact the result. But the issues around large part measurement requires a different mix of skills when compared to small parts, each having their unique issues blended with the common ones.

The two extremes of approach to Metrology upskilling are to work with an advisor or external expert to develop a metrology upskilling programme, quickly uplifting an organisations skill. Alternately, you can start by developing a single or group of champions within an organisation. A champion can act as the tip of the spear, proving benefit, helping to mentor others and guiding a targeted follow-up skills programme. This may be slower but can be more flexible.

An example of the type of skill/knowledge required

In part 1 of this article, I illustrated how temperature will impact measurement results. An increase in temperature will cause most materials to expand. The expansion would be in all directions and proportionate to its length, width, depth etc. So, what about a metal washer, does the inner diameter get smaller or bigger as the metal washer expands? The answer later.

Expansion is not an instant change. The thickness of material would mean any temperature changes would ripple through the part from the exterior, working in towards the core. Features of the part such as holes, slots and ribs all alter the rate of change as they thin or thicken sections of the part. They all create variation, as the product soaks up the temperature change. During that soak time, the temperature may change again, causing ripples to overlap ripples.

What is the source of the temperature change and how is it transferred? Human contact (body heat), factory heating blowers or radiators, seasons of the year, external roller shutter doors opening/closing and air movement are just some of the many sources and mixes. Do not forget uncertainty? Just how accurately are you measuring the temperature in the first place to calculate material change and therefore estimate effect? It would be wonderful to comprehend it all, but realistically just knowing it exists and being able to estimate it against your tolerance is a great start.

We have discussed the part, but remember that it is only an element of the whole process. Clamping devices if measuring on a system, and the measuring device itself can all move with temperature change, but by how much? Knowing how you can estimate the impact, from prior experience, generic testing or from engineering science is a useful skill, even if only to rule it out as a concern. Knowing what amounts to enough variation to cause concern and threaten your measurement processes capability is a core skill of the Metrologist.

How much of those skills and other measurement skills does a machine tool operator need to know to measure samples as part of process control? In my last article, I mentioned the balance in processes between creative freedom and fixed procedures. With no guidance or procedural constraint, you would argue that the operator needs to know it all, as they make all the process decisions. But if the measurement process has been planned with procedures specifying the measurement tool, basic method, cleanliness, temperature boundaries etc - then the operator needs fewer skills. If that process is automated, then of course repeatability is vastly improved. However, someone still needs to issue a procedure via a software interface to mitigate non-human variation, including what temperature band is acceptable.

Every measurement process is unique. Even the same process carried out seconds after the first can create meaningful variation, that is why we test. In one measurement process what may be a large cause of variation could be an insignificant cause in another. For example, changes in ambient light will not affect contact CNC CMM’s but can adversely affect a vision CMM’s capability in returning a consistent result. If you measure metals, humidity has no immediate effect on the measurement, but Nylon can expand and contract with changes in humidity as a percentage of its weight.

When I talk to engineers, I tell them it is surprising how much you already know about physics. You may not understand it fully, know how to quantify and evaluate its impact, but you see it every day. Proper training and education should link knowledge to skills and mix it with your own current experience.

Now, what about that washer. Firstly, think as a solid block of metal 100mm by 100mm by 2mm, expansion occurs in all directions, and so that block would expand in length, width and depth proportionately. If you drill a hole in that block, the metal that surrounds the hole will still expand. Therefore the hole would be stretched out with its surrounding metal and get bigger. How much it expands depends on the diameter of the hole, as it will expand at the same material expansion rate, per degree, per metre as the block. The hole, however, is smaller so will expand proportionately less.

If the washer is made of steel, and I state that the expansion co-efficient is 0.011mm per degree per metre. The whole washer at 100mm diameter if heated by 5 degrees, would expand by 0.0055mm. The hole in the middle is not steel, but it is surrounded by steel. The 50mm between the two inner blue lines represents the hole and at half the outer diameter would expand half the amount of the outside diameter, 0.00275mm.

So, the outside diameter of 100mm would expand by 0.0055mm but the inner hole would only expand by 0.00275mm

For more information and formal descriptions, you can explore: The Vocabulary of Measurement https://jcgm.bipm.org/vim/en/index.html

Calibration and Traceability https://www.npl.co.uk/calibration

Metrology https://en.wikipedia.org/wiki/Metrology

And don’t stop there, Metrology like Lean has a core, but it is also formed from many opinions and applied approaches, keep exploring, keep learning. 

The automotive industry faces a weight dilemma. In 2017, light-duty vehicles manufactured in the US weighed, on average, 4,044 lbs — not always living up to their name. New components and technologies add weight, yet environmental concerns also demand that manufacturers make them lighter. As a lighter material, aluminium can address this, but also presents machining challenges. Here, Eduardo Debone, Global Segment Manager – Automotive at Sandvik Coromant, explores how a single milling cutter might hold the solution.

Aluminium’s use in aviation predates even the first aeroplane as, in the late-1800s, Count Ferdinand crafted the frames of his famous Zeppelin airships from aluminium. Now, aluminium use in automotive engine blocks can provide considerable weight savings and improvements in fuel economy.

Elsewhere in transport, the power train of a European passenger car typically contains around 80kg of aluminium, which makes the engine and gearbox an obvious area for light-weighting. With aluminium increasingly-favoured, machine tool builders require dedicated tooling solutions to work with it.

Component complexity

The cylinder block is the main structure of an engine and is responsible for housing several moving parts that generate power to move the vehicle. For years, the block was made from cast iron alloys but aluminium alloys are now the common choice.

Manufacturing cylinder blocks involves the largest number of machines in automotive production, with complex and tight tolerance processes. Rough and finishing critical components such as cylinder blocks is expensive and time-consuming. It requires several different tools; which means increased setup and coolant to reduce heat during heightened friction machining. An engine’s cylinder head is an equally vital component, often made from aluminium. It conveys air and fuel to the combustion chamber and sits on top of the cylinder block, housing valves, spark plugs and fuel injectors. Aluminium may be lighter than cast iron counterpart, but its also softer. Therefore, poor finishes, burring and irregular tool wear are all common. So, how can automotive manufacturers get beyond these challenges?

A one-shot solution

Sandvik Coromant has found that innovation lies in simplicity. By implementing a single solution, rather than multiple tools for face milling operations, manufacturers can address the many challenges of aluminium. A one-shot milling cutter can provide both roughing and finishing in a single tool and reduce strain on aluminium to achieve higher quality results.

Sandvik Coromant’s solutions include several patented designs like the M5C90 aluminium cutter, part of the M5 product family, designed for the rough and finish face milling of cylinder heads, cylinder blocks and all-aluminium parts within wide cutter engagements, aside from thin-wall parts. The tool can complete the entire process from roughing to finishing, in just one go.

The tool can perform rough and finish milling in just one pass and, in many cases up to 6mm axial depth. We have seen it extend tool life by five times, with a 200% cycle time reduction.

A key feature of the M5 family is its step technology. A series of precise and long-lasting PCD tips arranged in a circular configuration to progressively remove a bit more material, both axially and radially. Also, the last tooth in the tool is a wiper design that provides a superior finish and flatness. The fixed position of the wiper and the teeth also eliminates complex and time-consuming pre-setting procedures.  As part of the environmentally friendly quest for better performance, selecting the right materials will be integral to making vehicles lighter. At the same time, the simple approach offered by tools like the M5C90 aluminium cutter offers manufacturers a way to overcome the demands and complexity of machining aluminium. Then, perhaps aluminium can take its rightful place as an antidote to the automotive industry’s weight dilemma.   

When Steve Knowles founded Newport CNC over ten years ago, Steve bought his first machine and worked evenings and weekends whilst keeping the day job. Steve’s first port of call was a HAAS VF4SS and high-end cutting tools from Industrial Tooling Corporation (ITC).

Building its early success in the high-end automotive industry, Newport CNC has recentlty made several investments. Before the COVID-19 pandemic, Newport CNC planned to move to a new factory and purchase its fifth HAAS, an ST20Y turning centre. The subsequent shutdown created several obstacles, but the five-employee business has now moved into its new 4,700sq/ft facility.

Commenting upon the challenge, Steve Knowles says: “Despite the pandemic, we are confident that our new machine and facility will help build an even stronger business.”

One of the bedrocks of the business from day one has been cutting tools from ITC and alluding to this, Steve continues: “I have used ITC tools for over 20 years and they have never let me down. When I started this business, my first port of call was Gary Bambrick at ITC. More than 80% of our work is aluminium machining and the ITC solid carbide aluminium cutters are beyond compare. I’ve had sales reps from virtually every tooling company trialling tools down the years and none can match the tool life, productivity, surface finishes and overall performance of the ITC range. Over 80% of our tools are from ITC and we have little interest in wasting time trialling alternate tools; time has proven we are applying the best tools available.”

The Milton Keynes Company typifies subcontract machining by manufacturing everything from commercial airline seats and high-end automotive work through to participating in the recent Ventilator Challenge. With 3, 4 and 5-axis machining and Y-axis turning, Newport CNC is equipped to meet the demands of industry.

For years, the ITC 3081 Series for aluminium has been the go-to cutter. “We started with several ITC solid carbide end mills, but found our sweet spot with the high-feed 3081 Series. The metal removal rates and the surface finishes are outstanding. We are using these end mills for everything from high removal roughing through to pocketing, profiling and finishing.” With such a glowing reference for the 3081 Series, Newport CNC now uses diameters that include 3, 5, 6, 10, 12, 16 and 20mm with a selection of square-end and corner radii from 0.5 to 3mm.   

As the company has evolved, so has its reliance on the wide range of ITC products. The company has adopted the Britcut Series of end mills in diameters of 4, 6, and 10mm. With centre cutting, a facet relief and a 30-degree helix, Newport CNC has opted for the TiAlN coated tools for a variety of material types. The success of both the 3081 Series and the Britcut range has paved the way for the introduction of the 3152 3-flute short length AlTiN coated end mills, the 2112 and 2012 Series of ball nose end mills for profiling and also the 4071 Series of chamfer tools.

ITC has been a longstanding distributor of Widia solid carbide end mills that have been a perfect complement to the UK manufactured ITC range, so when ITC widened its scope by adding the Widia indexable tools to its armoury, Newport CNC trialled the Widia VSM11 high feed 40mm diameter face mill. Comparing the Widia VSM11 against an industry-leading manufacturer, the VSM11 outperformed the competitor with a tool life improvement of 30% and a productivity increase of 40%, all whilst reducing the cost-per-insert against the previous tool.

ITC Caters for All Scenarios

“We have a standardised tooling strategy on each machine. With a 24-tool capacity, the first 10 positions are standardised on all machines. The first tools will be the 80mm and 40mm Widia VSM11 face mills with XDCT aluminium grade and geometry and also the XDPT steel insert designation for rough machining and facing every job that comes through the door, regardless of whether its aluminium, steel, stainless or heat resistant alloys. It also keeps our inventory and costs to a manageable level.”

“Positions three through to 10 will be ITC solid carbide end mills. In our other tooling positions, we have 3 and 6mm ball nose tools for profiling and finishing. This strategy allows us to standardise positions whilst giving staff familiarity. This streamlines programming and setups and we can thank ITC for having an extremely diverse range of high-quality tools that can support our business regardless of what comes through the door.” 

The larger the batch runs, the more important cycle times and tooling costs become. Nowhere is this more pertinent than the automotive industry where the properties of both the machine and cutting tool need to be optimised for the chosen process.

MAPAL works with a machine tool builder to optimise this philosophy. The specialist machine construction company places the workpiece and its machining process at the centre of development and devises a solution perfectly designed for the process. As Meinolf Wolke, Sales Team Leader at ELHA-MASCHINENBAU Liemke KG (ELHA) in Hövelhof says: “We have a unique approach to customer inquiries. We take all technical and economic requirements into account and decide whether an existing machining concept can be used for the process or whether an individual, application-specific construction is required.

Meinolf Wolke explains: “As well as providing the machine, we offer services from process development to automation. The machining tasks are as unique as the parts. A lot of complex machining work can be achieved with standard tools. But that often comes with drawbacks in terms of cycle times, quality, and cost-effectiveness, particularly when large quantities are being produced,” adds Alexander Wiesner, Technical Advisor at MAPAL.

“During the tool design phase, it’s essential to determine the necessary parameters for the process,” says Wiesner. To design the process in the best possible way, MAPAL often makes prototype tools that are used to carry out extensive tests with the part. “That helps the equipment manufacturers design the machine with the values identified during testing,” continues Wiesner. He says that MAPAL has had a long-standing partnership with ELHA in this area. One example is machining automotive OEM suspension arms with solid carbide drills.

“We were dissatisfied with the solution for drilling aluminium suspension arms,” remembers ELHA’s Friedhelm Dresmann. The company was using brazed PCD tools. The disadvantages were the high power requirement and the insufficient durability of the PCD edges on the solid drill step. ELHA turned to MAPAL who developed a hybrid tool. The tool tip is equipped with three-bladed, CVD-diamond coated ISO-indexable inserts. The fitting is machined using brazed PCD cutting edges on the second step of the tool.

MAPAL tested the new tool and in addition to the lower indexable insert costs, the positive blade geometry meant that less drive power was required. What’s more, the previous solution produced long metal chips that were no longer an issue. The indexable inserts at the tip of the drill that are under significant stress, can be quickly replaced to reduce maintenance costs. The suspension arm manufacturers’ production costs for each drilled bore were reduced by over 50%.

Another customer required a deep hole drill for machining stainless steel forged components. “This customer is a manufacturer of high-pressure fuel-supply distributors for petrol engines. This requires drilling deep bores in narrow, forged, stainless steel blanks,” says ELHA Project Leader Jörg Rodehutskors.

The difficult to machine job has a 300mm deep bore and the drill needs to experience as little axial deviation as possible, otherwise, the wall that experiences high pressure will fall below the required minimum thickness. Previously, the bores were machined in a separate, single-spindle machines with a single-flute deep hole drill. To optimise the processes, the customer asked ELHA for a solution with multiple spindles and parts leaving the machine finished.

MAPAL provided a drill with less deviation, less wear and faster cycle times. MAPAL developed a double-edged solid carbide drill designed to meet the requirements. With application parameters of Vc = 90m/min and f=0.5mm, the new tool life is 80m, three times longer than before.   

As one of Europe’s largest manufacturers of aerospace components, Gardner Aerospace places huge levels of pride in its precision, quality and cost-efficient streamlined manufacturing. It is for these reasons the company with manufacturing facilities around the globe has opted for cutting tool support from MSC Industrial Supply Co.

At the Broughton manufacturing site in North Wales, Gardner Aerospace manufactures structural components for aerospace OEMs from a variety of material types. To ensure the most efficient method of production, and that cost-effective solution are integrated into the business, the Broughton facility has in the last 12 months instigated a working relationship with MSC. The introduction of the MSC regional applications engineer Stuart Wiezniak to Gardner Aerospace was a decision based upon trust and reputation, with Stuart already yielding impressive results for Gardner Aerospace at its Hull manufacturing facility.

The new working relationship almost instantly yielded several cost savings and impressive productivity gains as soon as Stuart entered the Broughton site. With MSC’s decades of industry expertise, Stuart, a member of the application team was recently introduced to a troublesome component that with an annual production output of 7920, was tying up a HAAS S20Y turning centre for much of its daily three-shift operation.

The S98 stainless rod-end components with a 30mm diameter sphere required considerable material removal rates to create a flat on each side. On the HAAS, the limited rigidity of the Y-axis milling head and the three-jaw chuck clamping set-up created frequent machine alarms and stopped production. To eliminate this error, free-up machine availability, reduce cycle times and tooling costs, Stuart worked with Gardner to move the process to a Dahlih 4-axis machining centre with a BT40 spindle taper, and develop a fixture to hold and subsequently machine five parts in a single set-up. The results have been nothing short of staggering.

The previous setup on the HAAS turning centre utilised a 16mm diameter ball nose end mill with two indexable inserts, each with two cutting edges. This end mill from one of the world’s leading cutting tool manufacturers ran at 3mm depths of cut with a paltry material removal rate (MMR) of 6.64cm3/min and a feed rate of 246mm/min. By recommending an alternate machine tool, a different workholding configuration and more applicable cutting tools, Gardner Aerospace is now saving more than £37,500 per annum on this one job – and there is scope to add an even larger reduction to the already eye-watering cost saving.

By designing and manufacturing a fixture to clamp five parts, subsequently, machine the parts in a single set-up and then having the insight to utilise the 4th-axis to rotate the parts 180 degrees to machine the opposite side of the sphere, Gardner is realising massive productivity gains. MSC has been integral in this process and has reduced manual intervention, increased productivity and reduced costs.

From a tooling perspective, Stuart removed the previous indexable ball nosed tool and replaced it with a Dormer Pramet 32mm diameter high-feed end mill with five inserts and four edges per insert. Applying inserts with Dormer’s M6330 coating grade, the MSC expert increased the machining parameters beyond recognition. Running the new rough and semi-finish end mill at a 0.7mm depth of cut and a cutting speed of 180m/min, the MMR leapt from 6.64cm3/min to more than 50cm3/min. This reduced the cycle times from 5 minutes 49 seconds per part to just over 33 seconds.

The strategy applied by the MSC expert utilised the Dormer end mill for the semi-finish process and then complete the task with a larger 50mm diameter button tool. With 26 seconds of rough machining with the Dormer end mill and a seven-second cycle with the finishing tool, the total 33-second cycle has yielded Gardner Aerospace a saving of more than 5 minutes per part, a significant saving considering the annual quantities required. Commenting upon the strategy, MSC’s Stuart Wiezniak says: “The first challenge was to ensure machine availability to move the part from the turning centre to a machining centre. From there, we had the freedom to instigate process changes such as the 5-part fixture for multiple part machining. Devising a platform for rigid machining was the foundation block and once this was in place, we could look closer at tooling strategies and subsequent savings.”

“The beauty of creating partnerships with MSC is that we have access to hundreds of vendors and more than 120,000 product lines, so we are not constrained by a single source tooling supply. This means we can ensure the best tool for the application. In this specific application, the Dormer Pramet 32mm high-feed end mill was the optimal choice for high metal removal rates. For the finishing cycle, the rod end parts require an 8mm radius on the flats, so we opted for a 50mm button tool with four inserts and four cutting edges per insert. Running at a feed rate of 622mm/min with a single ‘finishing pass’ of 0.1mm DoC (depth of cut), the button tool delivers outstanding surface finishes with tool life of 400 parts per cutting edge.”

Summarising on the remarkable savings that have been made on this single process with the rod end parts, Stuart says: “Cutting tool strategies are always a balance of costs versus productivity rates. In this instance, the annual tooling cost increased by £321p/a to £2678, but we have slashed machine hours by 81% from 724 hours to 141 and the cost per part has reduced from £28 to £23. The saving of £37,542 not only absorbs the slight increase in tooling costs, but it also improves process reliability, frees-up machine capacity and man-hours and it improves component quality. We have exceeded customer expectations with regards to meeting the original objective whilst delivering the project goals on-time.”

The next step

Referring back to the ‘equally large cost reduction potential’ on this job, Stuart states: “The rod end parts has two different part families within the 8,000 quantity requirement. Some parts require a 24.8mm diameter bore on the machined flat whilst other parts need a 17.46mm diameter bore. Before the Covid pandemic and the subsequent lockdown, we investigated the possible options, trialled several tools and the results already look impressive. However, whilst we can expect another huge leap in cost savings, we have not yet had the opportunity for final approval with these tools. When the opportunity arises, I’ll be certain to deliver even more fantastic results for Gardner Aerospace.”

Renishaw is helping automotive supplier HiETA to move metal additive manufacturing (AM) from prototype processes into the commercial production of specialist heat exchangers. This process has been realised by adding a Renishaw RenAM 500M system that is dramatically reducing production times and costs.

Founded in 2011 to develop metal AM methods for producing complex, light-weight structures for various types of heat-management applications, HiETA manufactures recuperators, turbo-machinery and combustion components for micro gas-turbines, phase-change heat exchangers for fuel cells and integrated waste-heat recovery systems. HiETA now has over 25 staff that cover AM product development from initial design through to computational fluid dynamics (CFD) and finite-element analysis (FEA) through to manufacturing, testing and validation. The latest addition is the RenAM 500M a laser powder-bed fusion system designed for the production of metal components on the factory floor. Incorporating a powerful 500W laser to give faster processing than earlier models, the new RenAM 500M features automated powder handling to improve quality and reduced operator intervention.

Traditionally, heat exchangers are made from thin sheets of material welded together. The design complexity makes production both challenging and time-consuming, while the material used for the welding process adds to the overall weight of the part. Before the work at HiETA, little research had been undertaken into the use of AM for the manufacture of heat exchangers. The initial challenges were to confirm that AM could successfully generate sufficiently thin walls with high-quality surfaces, and then produce a complete component with the complexity of a typical heat exchanger. The third challenge was to move the process from the manufacture of samples and prototypes into low-volume production.

Solution

HiETA developed specific parameter sets for the production of leak-free thin walls in Inconel down to thicknesses of 150 microns. Both companies produced samples using a variety of settings on the AM250 at Renishaw’s facility in Stone, Staffordshire and then at HiETA’s base on the Bristol and Bath Science Park.

The test results enabled the companies to confirm the optimum parameters on the machines for thin-walled structures and also allowed HiETA to develop a design guidebook with parameters for heat transfer in heat exchangers manufactured using laser powder-bed fusion technology. Having achieved a leak-free wall, the next stage was a complete, full-size unit.

Two projects were undertaken with vehicle integrator Delta Motorsports. The first was a cuboid heat exchanger for electric vehicles. The second aimed to take the design of the components to higher levels of complexity. More complex shapes can improve performance, efficiency and reduce costs. The design chosen was an annular form that could be wrapped around other components and contain integrated manifolds. HiETA also used these projects to develop an extraction process for removal of excess powder material from the cores of the heat exchangers.

The first results on thermal transfer and fluid flow data were incorporated into the CFD and finite-element analysis programs used by HiETA. The first attempt at a complete product on the AM250 took seventeen days. This was reduced to eighty hours. Detailed testing showed that the component would improve performance and weight and volume by 30%.

“With almost all of our projects, we are trying to light-weight components and solve thermal management issues,” explained Stephen Mellor, Lead Project Engineer at HiETA. “Through our partnership with Renishaw, we have produced components that are typically around 40% lighter and smaller by volume than anything equivalent that is available on the market.

Following the success with the Renishaw AM250, HiETA invested in the more powerful RenAM 500M system to enable more cost-effective low volume production. “We are now producing parts for engines with real commercial applications and customers with very demanding requirements. Renishaw’s AM technology to gives high performance at competitive prices,” concludes Stephen.   

Having been entrenched in 3D printing and additive manufacturing (AM) for over 26 years, Dr Phil Reeves has a wide-ranging expertise and experience of the industry. In the first interview with Tanya Weaver, Phil discussed the barriers to AM; here he reveals adoption trends across various industries as well as discussing machine trends, especially those built for specific applications.

Today the use of additive manufacturing (AM) features in almost every industry. But as Phil Reeves stressed in the first article in this series, before adopting this technology users must consider how it will add value to the business.

“The question manufacturers should be asking is whether by using an AM machine they could cost-effectively redesign their product to give the customer a better product? A better heat exchanger, a better fuel injector, a better part of a pump - whatever that object is the question is whether it can be made better using the AM process and that’s where you get the business value of AM,” says Reeves.

There are industries where AM is creating such value and the one that is leading the pack is aerospace. An aircraft features thousands of parts, some of which are more suitable for the AM process and there is a lot of opportunities to use the technology to create these parts, especially in the engine. “Aircraft engines feature thousands of highly complex and high-value parts that are typically made of very expensive, exotic materials. All of these things play into the hands of 3D printing,” says Reeves.

However, not all parts of the engine are suitable for the AM process. In an engine, there is a hierarchy of complexity from static cold parts, static hot parts, dynamic cold parts to dynamic hot parts. The initial use of AM was for static cold parts, which are metal parts that are typically found on the outside of engines that don’t move and never get hot. For instance, inspection hatches and small manifolds for pumping oil and fuel.

Moving to inside the engine, there are static hot parts, which still don’t move but do get hot. For instance, these could be heat tiles and injector nozzles. Then the dynamic cold parts do move in that they rotate but they’re not at the hot end of the engine. An example is the fan blades produced by GE, which are made of composite but the very tip of them is 3D printed in titanium.

Whilst the three above are suitable for the AM process, there are currently no hot dynamic parts that can be 3D printed as yet. These are parts that are spinning rapidly inside the engine and are getting very hot in the process. Currently, most of these parts are cast using special alloys.

“There is certainly a lot of opportunities to use additive in the production of these parts but always the manufacture has to ask, what value does AM bring and does it improve upon what parts you have already? For instance, with the heat tiles, the reason why AM is used is because the geometry is complex and by creating a part with this design complexity allows for a really good heat transfer across the part. So they’re using the design complexity to make a better heat tile and so the value is through the design,” explains Reeves. 

Alongside aerospace is the space industry, which has also been using AM for many years and several additive parts have made their way into space. The advantage of using AM for these applications is that it’s very low volume, incredibly high-value parts that can be optimised to reduce weight, which has a huge impact on a space mission when considering that it costs £20,000 to send just one kilogram into space. “Every satellite that goes into space is rammed full of technology so if AM can be used to reduce the weight of the satellite infrastructure so even more technology can be packed, that is where the value lies,” says Reeves.

Next, is the medical industry, which is also rather established in its use of AM, particularly in the dental industry and for the manufacture of hearing aids, which have been 3D printed for years. “A market that is continually growing is medical implants, for instance - spinal, hips, knees, cranial, facial and so on. With the geometric complexity that can be achieved with AM means that the implant can be personalised for the patient and so offers a better implant,” describes Reeves.

With the automotive industry, although there are many applications that AM could potentially be used for, according to Reeves the economics of using it for part production only really makes sense for high-performance vehicles. For instance, Koenigsegg’s hypercars feature better-performing turbochargers whilst BMW’s i8 hybrid-electric supercar features several 3D printed parts including a fixture for the soft-top that has been printed in aluminium as well as a nylon window guide rail.

“Car manufacturing is the absolute opposite of AM as it’s all about producing parts for the lowest possible cost, and if something can be made in a modular fashion that is then shared among hundreds of different car platforms, all the better. Whereas AM is about low volume, high value and being highly customised,” he says.

The sector that is really grasping the opportunities of AM is the oil and gas and marine industries. The parts needed for both large and small-scale applications from hydraulic systems to thrusters play to AM’s strengths in that they are very low volume, highly complex and high-value parts. “A lot of the equipment used in these marine applications are made from the same alloys that are used in aerospace to make jet engine parts, which makes it easily transferable into oil and gas,” says Reeves.

The last sector is the rail industry, which is also seeing a lot more interest in AM. Taking cues from aerospace, which has been using AM to create low volume parts for its cabin interiors, the rail sector is starting to follow suit. For instance, rolling stock provider Angel Trains has started to 3D print replacement parts for passenger-facing parts on Chiltern Railways train interiors such as grab handles on top of seats. Angel Trains claims that it is currently working on producing more AM parts that are compliant with rail industry standards.

Alongside these industries that are adopting AM, there are now increasingly machines coming to market that are built for specific applications within these industries. “Historically, when the AM industry started, machine manufacturers were producing generic machines as they didn’t know what people were going to use them for other than prototyping. What’s happening now is we’re getting this divergence of machines where there are still generic machines that feature flexible technology but also machines that are dedicated to certain applications,” says Reeves.

An example of this is 3D Systems’ ProJet 6000, which is a specifically designed 3D printer for hearing aid production. Similarly, there are 3D printers that are only used to print dental models, such as dentures. For instance, Formlabs launched Formlabs Dental, a dentistry-centric printer called Form 3b that uses stereolithography (SLA) to create parts - from crowns and bridges to surgical guides, custom mouth guards and dentures - using dental resins.

“Another machine trend is the integration of 3D printers with other machine tools. This means that a CNC machine and an additive machine will be working together. The additive machine will be in a cell with a robot depositing material and the CNC machine will then be machining material. The aim is to make the workflow more automated because at the moment it’s still very manual,” says Reeves.

A machine manufacturer that has launched such an integrated system is Carbon 3D that has launched a 3D printer that integrates with a robot and washing system called Smart Part Washer, which is optimised to speed up post-processing. “It’s really very clever. There is an RFID tag inside the build platform, which the machine reads before it starts building the part. The robot then comes along, reads the RFID tag, takes the part out, knows what part its got, take it to the washing system where the washing system reads the RFID tag, works out how to wash the part, and then the part pops out the end. Then that build platform goes back the machine and it’s all completely integral,” he describes. 

But, of course, regardless of the machine being used, it all comes back to the value and business benefits that can be achieved through the use of AM. As Reeves says, machine vendors tend to shout more about their technology but don’t always reveal what the benefit of using it is and the value that it provides to the user. 

ELE Advanced Technologies Ltd is a company with an aerospace pedigree that dates back to 1955 when Earby Light Engineers (ELE) was founded to manufacture compressor blades for Rolls-Royce. In the 65 years since, the Colne company has expanded its scope by targeting the aerospace and automotive sectors.

In fact, the diversification into the automotive commercial diesel market has seen the company open a manufacturing facility in Slovakia to supply global commercial diesel engine manufacturers. In the last decade, ELE has invested heavily in production equipment for the manufacture of IGT, aerospace and automotive power generation components and assemblies such as blades, vanes and a range of turbine components. Part of this investment has included the installation of three Kitamura machining centres, with the latest machine arriving from Dugard at the start of April - during the pandemic lockdown period.

The Kitamura Mycenter HX500iG/630 from Dugard Machine Tools is an identical model and specification to an HX500iG/630 installed in 2017. Commenting on the purchase of the third Kitamura, David Dudley from ELE Advanced Technologies says: “The reason that we bought the third machine is that the process from the other two machines is such a repeatable process, we wanted a machine that we could plug in and play, and just start making components that will conform to specification perfectly.”

Alluding to the Mycenter HX500iG/630 machine, David continues: “The parts we are making on the Kitamura machines are being installed on an industrial gas turbine engine and they are manufactured from exotic materials like nimonic. The parts have very tight tolerances and the materials are very difficult to machine. With the Kitamura machines, you can load a part, machine it and then be confident that when you put it on the CMM, everything will be 100% correct.”

Extending upon this point and referring to the long cycle times required with the parts, David says: “The beauty of the Mycenter is that we can now use ceramic endmills from NTK and these allow us to remove material a lot faster than before. This gives us the ability to rough machine a lot faster and then come in with finishing tools for the final passes.”

Taking this productivity a step further, the Kitamura Mycenter HX500iG/630 machines have a 50 tool ATC as standard, along with a high-torque 12,000rpm dual contact BT50 spindle configuration and a twin pallet configuration. Discussing this, David says: “The reason for the twin pallet setup is twofold. Firstly, there is the obvious benefit that we can load one pallet whilst the other is ‘in-cycle’ which reduces our setup times and keeps the spindles turning. Additionally, we are introducing a lot of new products all the time. With the twin pallet, we can use one pallet for production parts whilst simultaneously using the next pallet for development parts. This ensures we can get new projects up and running without disrupting production. This allows us to mix-and-match our production.” Furthermore, the Kitamura incorporates a 500 by 500mm pallet with the facility for a 630mm pallet, if needed. Machining all faces with sufficient clearance is not an issue as the machines have an X, Y and Z-axis travel of 870 by 800 by 930mm.

Both Dugard and Kitamura actively promote the geometric precision of the machines and the hand-crafted manual scraping that makes the Mycenter range so precise. Commenting on this, David says: “The three Kitamura machines are heavy-duty machines and we know we can load both pallets on the machines and be confident that the parts coming off the machine are right first time. From a productivity perspective, we run the machines at 12,000rpm with 60m/min rapids. Both the Kitamura HX500iG machines in this cell are identical. They have the same spindles, tooling carousels and configurations.”

Looking at the machining strategy and potential for deflection when machining turbine components, David says: “This was something we clearly had to consider when we were buying these machines, but the robustness of the Kitamura range means that deflection is not a factor.”

Concluding on the service, David summarises: “The service has been fantastic. We bought the machine at the end of 2019 and the delivery was scheduled during the height of the pandemic. We are in the north of England and Dugard are in Brighton, but they delivered the machine and got it running in a matter of weeks, an excellent effort.”

As an independent research and technology organisation, TWI Ltd has recently invented a highly disruptive, new sub-surface machining technique called CoreFlow™. As soon as MTD magazine heard the term ‘Sub-Surface Machining’, we were intrigued, so here Senior Project Leader, Vito Di Pietro takes us through this ground-breaking innovation.

This new solid-state process is an evolution from friction stir welding (FSW) and friction stir channelling (FSC) that allows for sub-surface networks of channels to be machined into two-dimensional or three-dimensional monolithic parts in a single manufacturing step. These channels can then be used for applications such as heat exchange. Figure 1 shows a cooling plate demonstrator recently produced in aluminium (AA6082-T6) with infrared thermal imaging evidencing the circulation of liquid coolant.    

At the forefront of solid-phase friction welding and processing technology, TWI has been innovating welding research and development since the 1960s, responding to industry needs and providing consultancy and support to all industry sectors. Providing everything from advice on component design, process selection and quality issues, troubleshooting, feasibility and pre-production trials, application, and prototype equipment development, TWI has been responsible for many key innovations and developments in solid-phase joining. The most notable examples are friction stir welding (FSW), invented at TWI in 1991, and the development of linear friction welding (LFW) into a mature joining process for turbine blades.

The uptake of FSW has been very rapid, especially when compared with other innovations in materials joining. First demonstrated in the laboratory in late 1991, by 1995 it was in industrial production fabricating panels for refrigeration purposes. Many other applications rapidly followed including its use in launch vehicles, railcars, airframes, automotive structures, heat sinks and ships.

FSW uses a rotating tool designed to generate frictional heating to soften the adjoining metal to a point where it can be viscoplastically deformed and displaced around the tool (Figure 2). The FSW tool traverses the joint line between two parts, where its stirring action enables the formation of a solid-state weld. This has revolutionised welding of aluminium alloys due to the sub-melting point processing conditions, which prevent solidification cracking and porosity formation while reducing distortion and minimising the loss of parent material properties. The resulting joint has excellent tensile strength and fatigue and fracture properties.

Derived from FSW, Friction Stir Channelling (FSC) is an innovative solid-state process that integrates sub-surface networks within metal structural elements. The original FSC concept was patented by Rajiv S. Mishra in 2005. In his work, poor material consolidation during FSW was deliberately promoted to produce a continuous void along the tool path. However, despite its great potential, this technology has not yet been adopted by industry, mainly by not fulfilling the required repeatability, surface finish or design flexibility.

TWI has recently invented and patented a new stationary shoulder variant of FSC (SSFSC) which has overcome many drawbacks of conventional FSC. As shown in Figure 3, a stationary shoulder is employed to confine the nugget of viscoplastic material, limiting the flow of material extracted by the probe. With the appropriate rotation direction, the geometrical features of the probe causes part of the nugget material to be conveyed into the shoulder. The material extracted is then re-directed towards a series of vents in the shoulder and expelled.

As the tool assembly traverses along a pre-defined path, the process of extracting the material leads to the formation of a closed channel within the workpiece and the production of extruded wire.

The four main stages in the process are shown in Figure 4. The cycle is initiated by plunging the rotating probe into the plate and once the probe reaches its target plunge depth, the machine initiates its traverse motion along the workpiece, the plasticised material is conveyed upwards by the rotating probe threads, into the shoulder and then expelled as extruded material. This subtraction of material leads to the formation of a closed sub-surface channel.

Applications for CoreFlow™

CoreFlow™ already looks set to find revolutionary applications in the manufacture of heat exchangers, cooling systems, integrated fluid management and the light-weighting of structures. Heat exchangers can be found everywhere from cars to aeroplanes, but also communication platforms, satellites and ships.

The automotive opportunities

In the electric vehicle (EV) market, there is an increasing need for faster-charging rates, improved speed and autonomy, increased power density, and a general ambition to make EVs affordable. These expectations are resulting in increased heat generation and are driving a collective demand for low cost, compact, lightweight and efficient heat transfer solutions.

Battery packs release heat during charging and driving due to electric resistivity. This is aggravated for higher intensity charges and discharges. Currently, serpentine pipe heat exchangers are incorporated inside the battery pack to prevent excessive temperatures that could lead to cell chemical degradation or battery derating. These systems take up space, add weight and manufacturing complexity to the vehicle, therefore CoreFlow represents a huge opportunity to solve these challenges by manufacturing battery trays with integral cooling channels built into the metallic structure.

Another example is the thermal management of electric motors. These components heat-up mainly due to the resistivity of the copper windings and eddy-current losses, this excess heat is detrimental to motor performance. Cooling systems are usually incorporated into the casing based on natural or forced convection of air or liquid. CoreFlow™ could be used to incorporate channels in thin-walled motor casings for active cooling, reducing weight and improving performance.

The aerospace industry is another potential beneficiary. Aircraft engine cooling is usually performed by heat exchangers located between the engine and the nacelle, cooling engine oil using air or fuel. These components disrupt airflow, create drag and decreasing thrust. With CoreFlow™, cooling networks could be incorporated directly in the nacelles. The same applies to hydraulic cooling systems that could be replaced by integrated CoreFlow™ manifolds rather than hoses and pipes.

Currently, FSW is one of the most promising technologies for manufacturing heat exchangers. Their complex geometry currently forces engineers to split production in two stages (see Figure 5). Typically, a housing is machined from a solid block of metal that incorporates cooling features and channels to circulate the cooling fluid through the part. In the second stage, a lid is joined and friction welded to isolate the cooling channels from the environment. FSW has become the most effective solution for this process.

CoreFlow™ has overcome these challenges by machining the cooling channels in a single step. By creating a channel below the surface of a structure, CoreFlow™ provides an integrated method to vent heat from a part without having to add pipework or other complex and costly solutions.

This creates a simpler, more efficient manufacturing method, using approximately 20% less raw material, producing almost 80% less waste (in form of wire), and weighing less than its conventional counterpart (see Figure 5).

This new technique provides heat reduction and can be used for the production of anti-icing features on wings and flight control surfaces for aircraft. The technique can also be used to create lubrication networks for hydraulics, to embed instruments into a structure, to perform cable management or simply for light-weighting. Outside of transport, CoreFlow™ can be used for cooling data servers, communication infrastructures and radar installations or to manage the thermal load in manufacturing equipment – opportunities are huge.

Aluminium AA6082-T6 and AA1050-H14 plates with a thickness from 5 to 50mm have been successfully processed and the application has already moved on to flat and tubular demonstrators (see Figure 6 below) that feature channels along linear and helical trajectories. The demonstrators passed both leak and pressure testing, with leak rates well below 10-8 mbar∙L/s and pressure up to 9 bar.

The development of CoreFlow™

In the last few years, CoreFlow™ has been demonstrated and further developed by TWI. Trials have been conducted on an ESAB SuperStir™ machine (Figure 7) with a purpose-built FSW gantry fitted with TWI’s proprietary stationary shoulder system.

The probe used is a cylindrical proprietary cobalt-nickel-chromium alloy threaded probe with a diameter of 9.8mm and a length of 7mm. The shoulder has a flat surface, a 30mm outer diameter and a bore diameter of 10mm. The shoulder features four orthogonally-positioned, radial vents with 3mm diameter holes that increase to 5mm to ease the expulsion of plasticised material. The probe and shoulder are usually designed specifically for the material and application.

In Figure 8, an aluminium AA6082-T6 test piece with a thickness of 15mm has been processed with CoreFlow™ using two main process parameters; traverse and rotation speed.

In Figure 9, the superficial appearance of samples produced using rotational speeds varying from 400 to 1200rev/min and traverse speeds from 25 to 150min/min are shown. Fully-consolidated ceilings are achieved when combining low traverse speeds with low rotation speeds whilst increasing the rotation speed resulted in intermittent surface voiding; an effect more noticeable for higher traverse speeds tested.

All channels feature a flat bottom surface with well-defined edges, coincident with the probe outline (Figure 10). The channel produced is fully consolidated and is 9.89mm wide with a maximum height of 2.53mm and a minimum ceiling thickness of 4.46mm. From the micrograph, it is also possible to appreciate how the anisotropic grain orientation in the parent material, caused by the plate sample rolling process, transforms into a fully recrystallized microstructure in the channel ceiling due to the stirring action of the probe.

The material extruded in the form of wire can be used as feedstock for processes such as wire-based additive manufacturing or even welding wire. CoreFlow™ is capable of extruding an unlimited length of wire from a plate or a pipe.

This process, labelled ForgeWire, is of great interest for producing a spool of wire from materials with poor extrudability, such as alloys of aluminium or magnesium. Wire manufacturers or additive manufacturing process developers now have a quick option for producing wire with tailored chemical composition and from experimental alloy formulations (e.g. Aluminium-Lithium or Aluminium-Scandium), potentially even directly from the rolled product or cast billets.

TWI is continuing to develop CoreFlow™ by defining guidelines for use with different materials while working on a range of industrially-relevant demonstrators. With a variety of applications having already been proposed, this new friction technique is potentially the next paradigm shift forward in manufacturing technology.