Reaction Processing of Ultra-high Temperature W/Ta₂C-based Cermets

A reactive processing method was used to produce dense (>99.5% relative density) W/Ta ₂ C/Ta ₂ WO ₈ cermets from Ta ₂ O ₅ , WC, TaC, and phenolic resin. the powder compacts were reacted under vacuum at 1450°C and then densified at 1850°C. the microstructure of the cermets was examined using scanning electron microscopy and found to contain fine grains on the order of 1-3 μm in diameter. X-ray diffraction, transmission electron microscopy, and parallel energy electron loss spectroscopy were used to identify the composition and structure of the phases in the composites. the composites were found to contain approximately 47.5 wt% W, 47.3 wt% Ta ₂ C, and 5.2 wt% Ta ₂ WO ₈ . Crack-free and dense W/Ta ₂ C-based cermets were prepared by an in situ reactive sintering process without the application of pressure during densification.