It’s fair to say that there has been a certain level of scepticism about additive layer manufacturing (ALM). The idea of “printing” products by joining materials together, layer upon layer, rather than making them in more traditional subtractive manners such as milling, sounds such a radical and fantastical technology that it’s natural to harbour doubts.
But new figures show that the technology is being taken seriously by some significant players, especially in sectors such as aerospace, automotive and energy. The annual growth rate of ALM was 29.4% in 2011, with the industry expected to continue strong double-digit increases over the next several years.
The research, by independent consultancy Wohlers Associates, says that by 2015 the sales of ALM products and services will reach $3.7 billion worldwide, and by 2019 surpass $6.5 billion. Wohlers points out the extraordinary growth in the market for personal 3D printers – machines priced between $1,000 and $5,000.
These figures have made politicians in the US sit up and take notice. Last month, the Obama administration identified ALM as one of a handful of key technologies that could help to revitalise the stagnant US industrial base. So five agencies – the Departments of Defense, Energy and Commerce and the National Science Foundation and Nasa – have jointly committed to invest $45 million in a pilot research institute. The National Additive Manufacturing Innovation Institute, in Ohio, will look to centralise US expertise in 3D printing and attract investment from other countries.
Tom Kurfess, assistant director of advanced manufacturing at the White House Office of Science and Technology Policy, is a believer, saying that ALM is a technology whose time has finally come. Speaking last month in front of an audience of almost 4,000 scientists and engineers at National Instruments’ annual get-together in Austin, Texas, Kurfess said: “People have been thinking about ALM for many years. But now the technology is coming to fruition and we are getting all sorts of new materials. It is allowing us to move forward in interesting ways. This really is coming.”
So how does ALM work and where exactly is it being used? The technology uses thin, horizontal cross-sections from computer-aided design models and 3D-scanning systems to build up parts that can be difficult or impossible to produce any other way. It is primarily used to make physical models, prototypes, patterns, tooling components and production parts in plastic, metal and composite materials.
Wohlers Associates says that the technology has the potential to change the way organisations design and manufacture products. When used correctly, it can save impressive amounts of time and money. Some companies maintain that it has helped trim months off of design, prototyping and manufacturing schedules, while avoiding costly errors and enhancing product quality.
Kurfess, a mechanical engineer who graduated from the Massachusetts Institute of Technology and who has significant experience in high-precision manufacturing and metrology systems, thinks ALM will even enable the making of parts that would prove impossible with current production techniques. “We can start at the bottom of a part with steel and then functionally grade the material into aluminium at the top,” he says. “None of our existing computer-aided design systems allows us to functionally grade material. Yes, we can stack aluminium on top of steel, but we cannot do functional grading.”
Kurfess also believes that ALM will enable engineers to engage with CAD tools more effectively, particularly in the area of topological optimisation. “We can let mathematics decide where to locate material,” he says. “We can let the CAD system do the optimisation. The problem at the moment is, if you let the CAD optimise for weight, you may not actually be able to make the component. But with layered manufacturing, you can do it.”
Kurfess thinks the US is uniquely placed to exploit the potential of ALM, because it is home to the vast majority of existing machines – around 72% of all ALM machines are there.
He thinks that engineers will embrace ALM because it can make parts far more quickly than traditional prototyping technologies. “Pretty soon, we could even be using this sort of technology to make hard tooling,” he says.