Laser additive manufacturing: separating fact from fiction

11 Apr 2014

UK industry gathering organized by AILU considers challenges and growth strategies for AM/3D printing sector.

Acknowledging the growing importance of additive manufacturing (3D printing) the UK’s Association of Industrial Laser Users last week hosted a workshop to “help attendees separate fact from over-sold fiction”. The event was entitled Metal Additive Manufacturing: Opportunities in Applications and Improvements in Process Technology and took place in Sheffield, aka “the Steel City”, which has long association with metals processing.

Rob Scudamore Workshop Chair, who is Associate Director and manager of the Joining Technologies and Additive Manufacturing Group at TWI (formerly The Welding Institute), introduced the meeting saying, “Additive manufacturing, also known as 3D Printing, has seen a meteoric rise in recent years. From White House funding programmes in the USA, controversial press reports of AM handguns to ‘print me a Stradivarius’, it seems that anything is possible with this technology.

”Certainly, AM potentially offers large improvements in performance through enhanced design capability, combined with reduced cost and material consumption. The aerospace and medical sectors are leading the way in metallic AM, but applications are now being exploited in almost every industrial sector.”

The scope of the day-long AILU workshop reflected the broad skills base needed to exploit AM, spanning materials, testing, processing, design, CAD and mechanical engineering. It also showcased the variety of techniques used to add material to create components layer-by-layer, many of which are based around laser technologies. Topics included: technology development regarding processes; up and downstream factors; technical areas that are a commercial reality; case studies of AM successes; and strategic development of the technol-ogy in research and industry.

Here, optics.org reviews a presentation that stirred great interest among the attendees and in the coming weeks, we will bring further news of other key talks from the AM conference.

Dirty secrets

Of the many presentations covering different aspects of laser additive manufacturing, one notable topic exemplified how this technique is coming of age: “Design and Dirty Secrets: Getting the best out of Additive Manufacturing” was given by Robin Wilson, Lead Technologist, High Value Manufacturing at the UK’s Technology Strategy Board, the UK’s innovation agency, established by the Government to stimulate business innovation.

After introducing the Technology Strategy Board, Wilson told the 100-strong conference – drawn from a variety of academic and industrial sources across the UK – about what he meant by dirty secrets. “Despite all the great promise that laser additive manufacturing is showing, there are still a lot of seriously difficult engineering challenges that remain to be solved.

“The AM promise is that you can just print a desired solid product from a CAD file; just get your 3D CAD model, put it in a 3D printer and there you have it. But in fact there is a lot to be done before you can actually start making something, which we can call the digital data supply chain. Then you have to make it, which is also a multi-stage process, and afterwards you usually need to clean it up. There is inevitably a good deal of post-processing after you have made the basic product.”

Wilson showed a slide with an eleven-stage process to illustrate the point that there are many technical challenges – the “dirty secrets” – remaining to be solved. These are broken down into three phases: digital supply chain, additive manufacturing itself, and post-processing:

Stages of additive manufacturing

Digital supply chain: 1. Data generation (e.g. CAD, CT or MRI processes); 2. File translation; 3. File preparation, including orientation and support; 4. Build preparation, including packing and positioning; and 5. Build slicing of the part(s).

Additive manufacturing: 6. First layer creation (consolidate or deposit); 7. Index build platform (one layer thickness); or 7.1 material recoating (powder bed process); 8. Process next layer(s), by consolidation or deposition.

Post processing 9. Removal from machine (and spare material recovery/recycling); or 9.1 Heat treatment (stress relief); 10. Support removal (mechanical / chemical); and 11. Post process (thermal / chemical).

The TSB has acknowledged the importance of solving these “dirty secret” design challenges by last year launching and co-funding to the tune of £8.5 million no fewer than 18 projects across the spectrum of industrial research, applications and consumer markets. The umbrella name of the project is “Inspiring New Design Freedoms in Additive Manufacturing/3D Printing”. Co-funding from the companies involved takes the total investment to £15m.

Wilson added, “What we have tried to do with this call is to address these problems, including trying to solve the dirty secrets in 15 out of the 18 projects. It’s okay to ask for funding to address these areas that may not seem very sexy. So far, this is only a drop in the ocean from the TSB but a number of the projects are already making good progress.”

Amazing all of the attendees into stunned silence, Wilson concluded his presentation with a pledge that the TSB would next year make a further investment of one billion pounds into addressing the dirty secrets of additive manufacturing. But this was still 11.00 in the morning and it was the first of April. “But, in truth, we will likely be investing at least seven million pounds in future AM projects.”

About the Author

Matthew Peach is a contributing editor to optics.org.