Principal investigator: Markus Chmielus

University: University of Pittsburgh

Industry partners: General Carbide

Tungsten carbide (WC) is a material used in many applications including finishing tools, metal forming, wear parts and specialty components. Most of these applications require extremely complex-shaped parts. Due to the current limits of traditional subtractive manufacturing, the potential of WC applications is not fully explored, especially when it comes to complex internal part shapes or layered metal-WC composites. While additive manufacturing (AM) is increasingly adopted by industry to build highly complex metal parts, WC has yet to see this adoption due to a variety of aspects including crack initiation when exposed to extreme thermal gradients and rapid cooling as is common in energy beam-based AM. In a first project, this project team currently investigates the use of binder jet 3D printing without heat input during printing for WC. But this method will not enable layered composites or even repair by adding WC to WC parts. During a very limited feasibility test using direct metal deposition AM, it was shown that there is a process parameter space that does not result in cracking of WC during metal deposition. The project team (University of Pittsburgh research group of Dr. Chmielus and the General Carbide Corporation) will systematically investigate the influence of deposition parameters on microstructure, crack initiation, hardness and strength of layered WC-metal composites and WC on WC. Heat treatments and hot isostatic pressing will be investigated to reduce or even eliminate residual porosity and stresses in the composites, to achieve mechanical properties and reliability acceptable to General Carbide. The successful project will enable General Carbide to gain a competitive technological edge over international competitors and increase their portfolio by offering layered composites. The fellowships for two female students will further enable them to perform research in a fundamental and applied research project and directly engage with a local PA company.