Additive Manufacturing, which is also called as 3D printing started in 1984 as a prototype development process that has come a long way today as a mainstream manufacturing process. It has now become a process of choice to make complex, small, and expensive components that are designed specifically for AM. The affordability of AM has increased a lot during the last 10 years to bring the process from the design departments to the mainstream manufacturing. Initially, AM was adopted to do develop tooling for processes such as investment casting. After its successful use in tooling with the developments in the metal AM machines, it is now possible to use AM to directly produce the final tooling. For example, Michelin prints close to a million metal tire moulds per year, which will be used in its plans for moulding the tires.
Most of the AM processes utilised laser to melt the build material either polymer or metal powder. These have the limitations on the strength due to the sintering process involved. Newer processes are under development for example, XJet is jetting tiny particles of metal into a liquid that provides a much finer metal grain structure. Similarly, Inkbit inject-head printing system uses conductive inks with high resolution, and good material properties, paving the way for high performance functional polymer parts.
One of the early adopters of AM are for the use in medical and dental industries. For example, orthodontist can get a 3D scan of your teeth and then custom design the braces specifically for you to provide Invisalign braces. MRI scan is used to get patient-specific cranial implants that have fewer side effects while lowering surgical costs. University of California researchers have developed ‘MucoJet’, a 3D printed vaccine administration device that has the ability to shoot a pressurised stream of vaccination into the cheek tissue, removing the need for injections.
Other major adopters are aerospace where complex geometries with lower mass are required. GE Aviation has been making fuel nozzles for its next generation turbofan engines that have been approved to fly by FAA. Similarly, other aerospace manufacturers have adopted AM to build parts for aircraft that would reduce the weight while also decreasing the cost of flying by improving fuel economy. It is expected that in GE by 2020, 25% of its products will be impacted.
Automakers have utilised AM as prototyping as well as for tooling applications from the very beginning. However, now they are also using to produce the direct parts that will go into the cars. To this extent, German car makers appear to be investing heavily in AM.
Time, therefore, has come for all manufacturers to look at the use of AM across the value chain where it can be gainfully employed to reduce the bottlenecks while improving the economy. Also, the academic institutions should incorporate AM in their curriculum in the long run and in the short run offer tailored courses for industry that would help propagate the use of AM.
This is a guest editorial feature by Dr Nageswara Rao Posinasetti, Professor, Department of Technology, University of Northern Iowa