From art to part

HMR International Consultants' CTO, Graham Mitchell examines the rise and rise of laser additive manufacturing. Additive manufacturing first emerged in 1987 with stereo lithography from 3D systems. Solidifying thin layers of ultraviolet (UV) light-sensitive liquid polymer resin using a laser to form solid rapid prototypes, the technology continues to evolve to the present day. Fast forward to the 1997 AeroMat Conference, which was when I saw a new technology process whereby the liquid polymer resins were substituted by titanium particulate powder, the company in question, AeroMet  (a division of MTS Systems) had developed a process called laser additive manufacturing (LAM) that used a high power laser and powdered titanium alloys to create aerospace quality titanium parts directly from software designs without the need for forgings or castings and the associated tooling costs.  Until it shut down in 2005, AeroMet had successfully manufactured parts for the US aerospace industry. When it ceased operations, MTS announced that making titanium parts for the aerospace industry wasn't a profitable business model. In 1998, Optomec commercialised its own laser-engineered net shaping (LENS) metal powder system based upon technology developed at Sandia National Labs. LAM/LENS further extends the earlier techniques of rapid prototyping/rapid manufacturing. These techniques, now a $1 billion industry, use lasers to heat plastics into liquid and then form prototypes, decreasing the waiting period from months to weeks between conception and its appearance as a finished product. The future of LAM is also envisioned to advance beyond the production of monolithic parts and into the realm of producing advanced materials, e.g. functionally graded materials (FGM) and smart structures. As the understanding of the LAM process improves, so the feasibility of achieving such goals becomes more realistic. However, the path to flying the clearly heterogeneous FGM and smart structures is fraught with challenges in the areas of structural design, process qualification, and structural certification. The FGM process can produce materials with outstanding mechanical properties. Another plus is the process' ability to percentage mix powder streams of different materials. The ultimate goals are to make intricate and graduated material combinations in complex geometries and out of hard-to-machine materials. As engineers develop the know-how to build hybrid and/or graded structures, the design and design verification communities must concomitantly develop structural sizing and lifing tools and the associated qualification and certification techniques - if these structures are to find their way into any mainstream aircraft manufactures. Continued pressure from airlines to reduce operating costs and the environmental impact of aircraft means new aircraft will be based on very different product and manufacturing technologies from those currently in use. The ability of UK industry to develop and apply these technologies will be crucial to the future of the sector. Failure to achieve this will make it virtually impossible for it to generate the skills and capabilities to compete and secure a share of this work on future aircraft. It's clear there are some areas where current UK capabilities are becoming fragmented and fragile as a result of under-investment and a lack of a long-term strategy supported by both industry and Government.  By developing supply chains with high rates of innovation, rich in new technologies, the UK will be better positioned to offer the right products and services, at the right time and ahead of global competition. Industry continues to invest in technology development globally. However, capabilities in the UK cannot be sustained without joint industry and Government approach. The timescales for a return on investment and associated risks are too great for companies to bear on their own and even harder to bear lower down the supply chain. When LAM/LENS and FGM technologies are understood, matured and finally get going, $1 billion is going to look like a very small number indeed. genesis137g@hotmail.co.uk