Microstructure and mechanical properties of in-situ formed ZrC nanoparticles dispersion-strengthened tungsten alloy

W-Zr-C alloy with nanoscale ZrC particles dispersion was fabricated via powder metallurgy method using W, ZrH2 and nanoscale C powders as starting materials. The average size of in-situ formed particles is 55 nm. The smaller particles in the grain interior are dominantly ZrC particles. Zr decomposed from ZrH2 can also react with impurity oxygen to form ZrO2 particles and reduce the detrimental effects of oxygen on grain boundaries. The as-swaged W-Zr-C alloy is ductile at 200 °C, and the ultimate tensile strength and total elongation (TE) at 300 °C are 643.5 MPa and 23.5%, respectively. After annealing at 1400 °C, the UTS at 300 °C of W-Zr-C alloy is still as high as 611.4 MPa and the TE is 33.2%. The recrystallization start temperature of the as-swaged W-Zr-C alloy is between 1400 and 1500 °C, which is 200 °C higher than that of pure W. The in-situ formation of nanoscale second-phase particles via the dissolution-precipitation mechanism provides a feasible strategy for improving the low-temperature toughness and high-temperature stability of tungsten alloys.