On Tuesday 31st January, I attended the launch event for MAPP at the University of Sheffield. MAPP is an Engineering and Physical Sciences Research Council (EPSRC)-funded Future Manufacturing Research Hub (10 million GBP over seven years), and the acronym refers to 'Manufacture using Advanced Powder Processes'. It’s important to understand that this is not just about additive manufacturing (AM), and it’s not just about metal powders! Although if the launch is anything to go by, they are the two subject areas that most people want to talk about.
I tried not to have any pre-conceptions about the event, or the project itself, ahead of arriving in Sheffield. But driving over the very foggy Pennine hills, at a snail’s pace, I certainly wasn’t expecting such a high turnout—there were more than 150 delegates. This attendance level certainly made for a lively, busy and informative day. The speaker line-up was stellar and positively reinforced the composition, mission and intent of the MAPP project.
That mission, posted around the venue was hard to miss: ‘MAPP's vision is to deliver on the promise of powder-based manufacturing to provide low energy, low cost, and low waste high value manufacturing routes and products to secure UK manufacturing productivity and growth. Our mission is to work with academic, commercial and innovation partners to drive the research needed to solve many of the fundamental challenges limiting the development and uptake of many powder-based processes.’
Of course, this puts a spotlight on the age-old dichotomy that exists between academia and industry, and MAPP—in line with the increasing number of manufacturing Catapult centers across the UK—serves as a functional conduit between the two.
MAPP is essentially a consortium of five universities (Sheffield, Imperial College London, Leeds, Manchester and Oxford) and 17 industry partners (powder material suppliers and OEMs). The people I spoke with were from all sectors. They were open, enthused and motivated by MAPP and keen to contribute, believing the output would be exponentially more positive.
According to Prof. Iain Todd, director of MAPP: ‘We are in an exciting time for powder-based manufacturing. New market opportunities are rapidly opening up across a diverse range of high value sectors such as aerospace, energy, medical and automotive.’
Few would argue with this; the number of materials companies focusing in on powders, particularly metal powders, is significant. This is because demand is increasing dramatically. While the opportunities are real, there are, as you might expect, challenges and barriers, and these were identified by Prof. Todd as: variability of input material and thus process outcomes; lack of explicit process understanding; absence of suitable real-time modeling; no direct link from processing to in-service performance; and a skills gap for the next generation of engineers to make this all happen.
The professor stressed this last point: ‘Time and again, I hear it over and over—we need the people, new people that understand these issues and have the experience to overcome them.’
We all know this is true, but it was not directly addressed on the day. It certainly needs more focused attention.
Luckily, you don’t have to be a materials scientist to understand fully the challenges Iain was talking about. At the most basic level, the quality of the input (powder) determines the quality of the outcome (part). This requires time and cost-intensive work by materials scientists, but is vital for the progression of the AM industry.
To take one example, the characteristics of high-quality powder for the laser melting process do not necessarily translate directly to the electron beam melting (EBM) process. One step on from that is how the powder material reacts in-process. This is currently a big barrier due to limited variable output monitoring capabilities.
The goal is consistent, reliable, certifiable outputs. The way to do this, according to the MAPP vision, is to design the powder material for the process and then monitor that process with dynamic control via machine learning, ensuring the output has the necessary quality built in.
The themes of the MAPP research program tie in closely: in-situ process, characterization and modelling and control. Much of the rest of the day drilled down into these themes, with presentations from Rob Sharman, global head of AM at GKN Aerospace, Peter Lee from the University of Manchester and Research Complex at Harwell, Alison Wagland from Johnson Matthey, Andrew Bayly from the University of Leeds and Phil Carroll, CEO of LPW Technology.
I couldn’t keep up with all of the science, but some of the big picture themes that emerged gave me plenty of pause for thought in terms of what still needs to be achieved with AM to meet the needs of more widespread industrial applications.
The big one, after powder quality, which recurred throughout the day, was in-process monitoring. This goes way beyond putting a camera inside the build chamber of a hardware system. To get the certified part quality demanded by many industries, especially the highly regulated ones such as aerospace and medical, in-process monitoring demands critical information at the nano-scale.
A couple of stand-out technological advancements in this area were highlighted by Peter Lee. Lee talked about his work at the Research Complex at Harwell which focuses on the in-situ AM synchrotron, set up to use the Diamond Light Source (DLS) facility. Peter explained that the DLS is 10 billion times brighter than the sun, and the extremely high energy X-rays permit the characterization of metal products inside and out, which in layman’s terms means you can look through very thick or dense metal. This means that it is possible to look inside powdered metal materials to better understand how to make them and what happens to them as they are processed inside an AM system.
Peter also went on to outline some of his work at Manchester University which involves developing an AM process replicator. Essentially this enables system users to see the meltpool in-process. He reported, and showed, some very encouraging results that are allowing for the characterization of metal powders in-situ.
Another bombshell moment came from Phil Carroll of LPW Technology, when he focused on the user costs of metal AM with powder bed processes. LPW is a multi-disciplinary company focused on AM but with powder materials as a primary discipline. Using in-house costings, Phil illustrated how waste is still an issue with AM. I’m following up on this and will cover it in more detail in a separate feature, as it needs attention.
My day in Sheffield also highlighted some fascinating research into future manufacturing technologies. In particular, diode area melting (DAM) got my attention. It’s a process that was described as being similar to hollow structural sections (HSS) in terms of being fast and scalable in its approach with stainless steel material. The process uses laser modules with higher wall-plug efficiency compared with traditional fiber lasers, and laser spot overlap and focus can be adjusted to provide efficient optical pre-heat and component stress reduction. Moreover, DAM has the capability to instantaneously switch laser bar wavelength, enabling the processing of different materials. Seemingly a very interesting emerging AM powder bed process.
I was also very interested to learn more about Fast Forge, a new process for the production of aerospace-grade titanium alloys. This is a University of Sheffield project, rather than directly part of MAPP. It is claimed to provide engineers with more design flexibility and potentially lead to improved buy-to-fly ratios. This is being achieved through research into a new process that will transform rutile sand into novel titanium alloy aerospace components in the following three steps: production of titanium powder from the rutile sand; field-assisted sintering technology; and a one-step forging process.
In all, the MAPP launch event was hugely encouraging and I look forward to seeing where this goes. I will certainly be registering for the first industry conference in 2018 to find out more. For industry and academia there will also be engagement and outreach programs opening up.
In closing, I just want to relay a conversation I had with a source from an automotive company in attendance. When I asked how things were going, the response was: ‘We’ve come a long way in 20 years [of using additive tech], we are doing what we did 20 years ago but much more efficiently, much more cost-effectively and in much higher volumes. We’re still waiting for the next step-change though, but it does feel like it’s close.’