Synthesis and characterization of porous tungsten carbide with added tungsten silicides

Abstract

Porous materials made of commercial tungsten carbide (WC) with the addition of thermally obtained tungsten silicides (WSi2 and W5Si3) were made. The main research's contribution is firstly finding optimal conditions for synthesis tungsten silicides from elementary powders, and lately obtaining porous materials with excellent cavitation resistance. A phase transformation during synthesis of silicides was studied by changing temperature and time of heating. Obtained silicides were added to WC in different mass percentages. Mixtures were spark plasma sintered. Nanoindentation tests were performed on sintered samples, as well as cavitation erosion testing accompanied by measuring of mass changes and the profilometry measurements to scan the surface. Microstructure and morphology were determined by scanning electron microscopy (SEM), while porosity percentages based on SEM images were calculated by computer software QWin.