Sandvik Additive Manufacturing, Sweden, announces that it has developed a technology for producing a 3D-printed diamond composite part with a complex shape, extremely high hardness, and exceptional heat conductivity. The diamond composite also provides low density, very good thermal expansion, and “fantastic” corrosion resistance. According to Sandvik, the diamond composite is three times stiffer than steel, with heat conductivity higher than copper, thermal expansion close to Invar, and density close to aluminum.
The process involves additive manufacturing and a proprietary post-processing method that enables fabrication of composites that can be formed into almost any shape, even those that are highly complex. Most of the composite is diamond, but to make it printable and dense, it is cemented into a very hard matrix material (which Sandvik has not revealed), keeping the most important physical properties of pure diamond.
“Our additive manufacturing process is highly advanced,” says Mikael Schuisky, Head of R&D and Operations at Sandvik Additive Manufacturing. “We are printing in a slurry consisting of diamond powder and polymer using a method called stereolithography, in which complex parts are produced, layer by layer, using ultraviolet light.
“The step after the 3D-printing is even more demanding. This is where Sandvik has developed a tailor-made, proprietary post processing method making it possible to achieve the exact properties of the super-hard diamond composite. This step was extremely complicated. However, after extensive R&D efforts and several trials, we managed to take control of the process and made the first 3D printed diamond composite.”
