On Tuesday I attended the launch event for MAPP at the University of Sheffield. MAPP is an EPSRC funded Future Manufacturing Hub (€10 million 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, and it’s not just about metal powders! Although if yesterday 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 Pennines, at snail 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, to say the least, and positively reinforced the composition, mission and intent of the MAPP project. Said 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 manufacturing catapult centres across the UK, serves as a functional conduit between the two. MAPP is essentially a consortium of five universities (Sheffield/Imprerial College London/ Leeds/Manchester/Oxford) with 17 further partners from industry (powder material suppliers and OEMs). The people I spoke with on Tuesday from all sectors were certainly open, enthused and motivated by MAPP and keen to contribute input 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 that are focusing in on powders, particularly metal powders, is significant. This is because demand is increasing dramatically. While the opportunities are real, as you might expect there are challenges and barriers. These were specifically identified by Prof Todd as being: variability of input material and thus process outcomes; lack of explicit process understanding; absence of suitable real time modelling; no direct link from processing to in-service performance; and a skills gap for the next generation of engineers to make this all happen. Indeed, the professor stressed this last one, as an issue that: “time and again, I hear it over and over. We NEED the people — new people that understand these issues and the experience to overcome them.”
This last one was necessary to say, because it’s true, we all know that it’s true but it was not a direct issue addressed on the day. It certainly needs some grave attention though.
You don’t have to be a materials scientist to fully understand the challenges Iain was talking about — good job really because I don’t even come close. But as the most basic level, when it comes to powder manufacturing processes: the quality of the input (powder) determines the quality of the outcome (part). You might be thinking “Duh!” but actually in terms of the current situation, the quality of powders and the many different ways of producing powdered material that have a direct effect on that quality is occupying the activities of many material scientists. It is time and cost intensive work, but vital for the progression of the AM industry. Moreover, the characteristics of high quality powder for, say, the laser melting process do not necessarily translate directly to the EBM process. One step on from that is how the powder material reacts in-process. Currently this is a big barrier in that there is only limited, if any, monitoring capabilities which contributes to output that is variable. The goal is consistent, reliable, certifiable outputs. The way to do this, according to the MAPP vision is to make the powder material designed for process and then to monitor that process with dynamic control via machine learning such that the output has the necessary quality built in.
In line with this, then, Prof Todd outlined the three themes of the MAPP research programme: in-situ process, characterisation 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; Peter Lee from the Uni of Manchester & Research Complex at Harwell; Alison Waglund from Johnson Matthey; Andrew Bayly from the Uni of Leeds; and Phil Caroll, CEO at LPW.
I couldn’t keep up with all of the science, my brain is just not wired that way, but some of the big picture themes that emerged from the day gave me plenty of pause for thought in terms of what still needs to be achieved with additive manufacturing to meet the needs of widespread industrial applications.
The big one (after powder quality), which recurred over and over throughout the day was in-process monitoring. If you actually stop and think about this, it goes way beyond putting a camera inside the build chamber of a hardware system. Which, if I’m honest, is kind of how I thought about it. To get the certified quality of part demanded by many industries, especially the highly regulated ones such as aero and medical, in-process monitoring demands critical information at the nano-scale.
A couple of stand-out technological advancements in this area were highlighted on Tuesday by Peter Lee. Lee talked about his work at the Research Complex at Harwell which focuses on in-situ AM synchrotron set up using the Diamond Light Source (DLS) facility. This revelation blew my mind somewhat, as Peter explained that the DLS is 10 billion times brighter than the sun. I seriously thought I’d misheard, but he repeated it (and I triple checked). The extremely high energy x-rays of the DLS permits the characterisation of metal products, inside and out, which in layman’s terms means you can look through very thick / dense metal. Peter expanded how this means that it is possible to look at materials in different ways, and more specifically look inside powdered metal materials to better understand how to make them and what happens to them as they are processed in side 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 characterisation of metal powders in-situ.
Another bombshell moment came from Phil Carroll of LPW, when he focused on the user costs of metal AM with powder bed processes. LPW is a multi-disciplined company focused on AM, however powder materials is a primary discipline. Part way through his presentation, Phil highlighted one of the often cited advantages of AM, namely how it minimises material waste. He then went on to illustrate through some costings developed in house, how waste (and the inherent costs) is still an issue with AM. I’m following up on this and will cover it in more detail a separate feature as it needs attention.
Finally, my day in Sheffield also highlighted some fascinating research into future manufacturing technologies. In particular, Diode Area Melting got my attention. It’s a process that was described as being similar to HSS in terms of it being fast and scalable in its approach with Stainless Steel material. The process uses laser modules with higher wall-plug efficiency compared with traditional fibre 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 Sheffield Uni project, not directly part of MAPP, but notable nonetheless. It is said that the Fast Forge technology will 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 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 programmes opening up.
In closing, I just want to relay a conversation I had with a source from an automotive company that was 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.”