Principal investigator: Markus Chmielus

University: University of Pittsburgh

Industry partners: General Carbide

Tungsten carbide parts are used in a variety of highly demanding applications-including tooling-for a wide range of industrial wear and metal forming applications. Those tools are currently limited by the traditional subtractive manufacturing methods. While additive manufacturing (AM) is being increasingly adopted by industry to build highly complex metal parts, the commonly adopted energy beam-based AM (e.g., selective laser melting/sintering), produces large thermal gradients through repeated rapid heating and cooling. Tungsten carbide cracks when exposed to these extreme conditions. Binder jet 3D printing selectively joins powder particles via binder in a layer-by-layer fashion and does not introduce high temperature gradients during printing. Therefore, it does not lead to fracture during AM. While the choice of this AM method seems trivial, optimizing print parameters for non-standard powders with high porosity and varying flow properties requires a careful and systematic study to produce parts that are dense and stable enough for hot isostatic pressing (hipping) that will densify and harden them. During the project proposed here, Dr. Chmielus’ research group from the University of Pittsburgh and the General Carbide Corporation will investigate the best base powders that can be used in binder jet 3D printing, optimize the printing process for these powders to produce stable parts, as well as study in detail the sintering and hipping process so that final parts have mechanical properties and shape changes acceptable to General Carbide. The successful project will enable General Carbide to gain a competitive technological edge over international competitors, increase their portfolio of parts with highly complex shapes, and decrease production costs for the most demanding low count parts. Additionally, two female students will have the opportunity to perform research in a fundamental and applied research project and directly engage with a local PA company.