The ExOne Company reported it has developed a clean-burning metal binder that will make possible binder-jet printing of in-demand nonferrous metals like aluminum and titanium, which are sensitive to carbon residue left behind by other binding agents during sintering. CleanFuse is a patent-pending formulation that will be commercially available during Q1 2020.
ExOne develops and manufactures various models of 3D-printing or additive manufacturing (AM) machines and printing products, including binder formulae that are mixed with printing materials (in this case, metals) to ensure the powder constituents hold the intended shape.
In binder-jet 3D-printing, a CAD file is translated to .stl format to guide the motions of a printer as it builds a component in layers, depositing metal, sand, or ceramic to create the solid shape. Metal powder must be sintered after the shape has been completed, in order to fuse the particles into single metal unit.
However, when binders are not burnt away cleanly during sintering, carbon residue can alter the chemistry and thus the performance of some sensitive metals. According to the developer, one benefit of 3D printing metals with CleanFuse is preserving consistent part performance, including its weldability — which is important in aerospace, automotive, and defense manufacturing, where parts may be integrated or assembled into a final product.
ExOne binder-jet systems already are qualified for printing several metals, including stainless steels 316L, 304L, and 17-4PH. However, a clean-burning binder is a preliminary step to establishing binder-jet 3D printing for some high-demand metals and some ceramics.
"CleanFuse is an important advancement for the field of binder jet 3D printing,” stated CEO John Hartner. “In addition to enabling the future binder-jet 3D-printing of aluminum and titanium, CleanFuse also will be important for 3D printing some beta materials now moving through our strict qualification process, such as Inconel 718 and 625.”