Tungsten and tungsten alloys have been manufactured via Vacuum Plasma Spray (VPS) forming for a number of extremely high temperature applications. The results of a systematic study of tungsten alloyed with rhenium and reinforced with hafnium carbide are discussed. A microstructural analysis along with tensile and thermal conductivity data at room temperature and elevated temperature are presented. Microstructural data shows a significant reduction in grain size for alloys containing hafnium carbide due to pinning of the grains by the reinforcement. Mechanical test results show the tensile properties of tungsten are improved by rhenium additions as small as 2% with hafnium carbide additions below 1%.  In contrast, high rhenium additions (25% or greater), significantly reduce room temperature thermal conductivity of tungsten due to the relatively low thermal conductivity of pure rhenium.  However, at high temperatures (greater than 1000ºC), the lowering effect of rhenium additions on thermal conductivity of tungsten-rhenium alloys is greatly reduced.