In a jointly funded project by Ford Motor and ExOne, experts have developed a patent-pending process for binder-jetting 3D printing and sintering of aluminium. The properties are said to be comparable to die casting.
"3D printed and sintered components are a real breakthrough for the automotive industry," says Harold Sears, Ford's technical manager for additive manufacturing. "Even though the 3D printing process is very different from stamping body panels, we now have a much better understanding of the behaviour of aluminium and its advantage in building lightweight vehicles." Currently, some aluminium alloys can be processed with laser 3D printing, but the process is considerably slower than the method developed by Ford and ExOne, they say.
The new process, he said, will help Ford cost-effectively produce complex components designed specifically for additive manufacturing. At the same time, the size and weight of the components can be reduced and the efficiency of the entire process improved.
The new innovation is based on the binder jetting process. The process is also known as "3D printing" and goes back to developments at the Massachusetts Institute of Technology (MIT). There, in the early 1990s, a machine was built based on an inkjet printer that shot the binder onto the powder instead of ink onto the paper.
The final bonded metal part is then sintered in a sintering furnace to fuse the particles into a solid part, increasing the strength and integrity of the metal. The sintering process for stainless steel is well known, but high densities of more than 99 per cent are an industry breakthrough for aluminium.
The joint development project between Ford and ExOne was launched in 2019. Final material and repeatability testing was led by Ford.
Further information: www.exone.com/aluminum
Photo: ExOne