Abstract
The transverse-rupture strength of WC-(10, 20)%Co alloys oxidized in air at the temperature of 973-1173 K for the time of 0.3-1.8 ks was studied as a function of Co content, carbon content of alloys, WC grain size and r-domain size. It was found that the strength of the alloy decreased owing to the surface oxidation and the strength decrease became larger with rising temperature and increasing time. It was noted that the strength decrease was enhanced with increasing r-domain size. It was also found that the rate of oxidation was faster in the domain boundary than inside the domain, so that the domain boundary after oxidation acted as a notch during transverse-rupture test, leading to the strength decrease.
