Anyone who works with advanced powder processing in manufacturing is familiar with the challenge of achieving consistent results using variable materials. Tackling this issue and delivering on the promise of powder-based processes are some of the key objectives behind the EPSRC Future Manufacturing Hub, MAPP. University of Sheffield’s Iain Todd, talks powder, collaboration and crisp packets.
You can argue that the idea for forming the MAPP (Manufacturing using Advanced Powder Processes) Hub began with a packet of crisps. In 2015, I was attending a session on variability in manufacturing at a food-focused conference in Cambridge when someone made an interesting comment that stuck with me: ‘potatoes come in all shapes and sizes and yet we are still able to make packages of crisps that look and taste the same each time.’
With a background in materials processing, I immediately drew a comparison between the potatoes and metal and polymeric powders – they are all variable materials. Generally speaking, putting variable materials through a fixed process will achieve a variable outcome. By accepting the variation of the starting material (like potatoes or powder) and varying the manufacturing processes, however, we can achieve relative consistency (like packets of crisps).
The pharmaceutical industry takes a similar approach – they design the quality into the part, rather than testing it afterwards.
They start by classifying the materials they put in and modify the process to accommodate them to ensure a consistent quality of the outcome. Food and drugs are both highly regulated industries and have therefore opened the door for other variable materials like powder when it comes to manufacturing.
This thinking lies at the heart of MAPP. By bringing together teams and specialists from University of Sheffield, Leeds, Manchester, Oxford, Imperial College London and University College London as well as 17 industry partners, MAPP is able to combine skills and expertise with the aim of delivering on the promise of powder-based manufacturing: to provide low energy, low cost, and low waste, high value manufacturing routes and products.
Addressing problems, not processes
As a collective, MAPP is process agnostic, we work across emerging powder-based manufacturing technologies including spark plasma sintering (SPS), freeze casting, inkjet printing, layer-by-layer manufacture, hot isostatic pressing (HIP), and laser, electron beam, and indirect additive manufacturing (AM). Rather than owning these processes, however, we own the problems with advanced powder processing – this allows us to take a step back and look at the fundamental challenges that limit the development and uptake of powder-based processes like cost, consistency, repeatability and waste.
MAPP’s research focuses on a range of engineering materials that lend themselves to powder processing – from advanced ceramics to polymers and metals – all with the objective of addressing common problems and issues to achieve ‘right first time manufacturing’. We apply machine learning, advance monitoring and control, combining these with live data from hybrid models to create a picture of what will happen to the powders using various manufacturing methods. We can then compare these models to the actual effects of powder during the manufacturing process. This ‘live testing’ can be used to develop rules for manufacturers using advanced powders to improve components.
MAPP’s Tailorable & Adaptive Connected Digital Additive Manufacturing (TACDAM) project is an example of machine learning at work. Combining expertise from industry and academia, TACDAM is focused on developing an adaptive quality assurance model by introducing parametric design as a key process variable to demonstrate the capability to deliver quality outcomes to the automotive industry. This model-based approach helps to optimise the part life-cycle and identifies methodologies that ‘learn’ from data, contributing to the better fundamental understanding of the manufacturing process.
Control Engineers – the ‘secret sauce’
Understanding of the underlying physical principles related to materials processing is key to the control of material form, integrity and function and, ultimately its economic value. Including control engineers in the mix of MAPP’s specialists in powder atomisation, energy and energy storage, ceramics and ceramic matrices, computer tomography, light sources, higher speed and novel additive processes help to make up the ‘secret sauce’ that contribute to its success in tackling the problems associated with advanced powder processes. By optimising active control, these engineers allow machines to run in virtual isolation, essentially enabling the closed loop manufacturing of parts. This level of advanced control helps to maximise resources and minimise waste, supporting MAPP’s vision of achieving 100% material use 100% of the time.
And speaking of maximising resources, finding ways to minimise powder wastage will go a long way to realising the economics of advanced powders. Industry partners, particularly in the ceramic sector, are making good headway in this area by using large and small powders in the same factory. This practice means all processes can take place under the same roof and therefore make the most of the resources and materials – a trend we have yet to see with metal powders. We’re also seeing work taking place with the end of life use of powders and oversplash aimed at reducing waste and fuelling the move to 100% utilisation.
These are only a few illustrations of the work MAPP is achieving through collaboration across industrial and academic sectors. We are committed to delivering low energy, low cost and low waste, high value manufacturing through advanced powders. Together we are making headway in solving the fundamental challenges that limit the uptake of powder-based processing. We are opening doors for greater innovation and adoption across a number of industries, with the ultimate goal of growing British manufacturing.
Professor Iain Todd – Director, Manufacture using Advanced Powders and Processes (MAPP), EPSRC Future Manufacturing Hub
To learn more about MAPP and the projects it supports, head along to Additive International’s pre-conference day on 9th July. Register here: https://www.additiveinternational.com/register/