Sintering of tungsten carbide cermets with an iron-based ternary alloy binder: Processing and thermodynamic considerations

Abstract

Cemented tungsten carbide materials are traditionally bonded using a cobalt matrix, resulting in a material that possesses a unique combination of exceptional properties. However, cobalt has been recently classified as “reasonably anticipated to be a human carcinogen,” and thus, removal of this hazardous phase is desired for many applications. This research focuses on the production of tungsten carbide bodies cemented with a non-hazardous iron-based alloy binder phase. This binder has roots in the previous transition metal binders and additives for tungsten carbide and is based on the principles of high-entropy alloys; however, it relies on a novel means of carbide formation and dispersion from prior investigations. Sintering studies were conducted through uniaxial hot pressing, field-assisted sintering techniques, and pressureless sintering techniques. While some of the results of hot pressing and field-assisted sintering technique were positive, the resultant mesostructure exhibited an undesired, graded, heterogeneous form. Pressureless sintering, on the other hand, was capable of producing a homogeneous microstructure with high theoretical density along with promising hardness and indentation toughness values.