Abstract
Fine W-Cr alloyed powders (up to 30%Cr) were produced by the carbon and subsequent hydrogen reduction of tungsten and Cr2O3 powder mixtures. The powdèrs produced showed excellent compactibility. The green compact formed at the pressure of 4 ton/cm2 was easy to handle. These powders showed also excellent sintering properties. The densities of alloys sintered at 1500°C for 3 hrs in hydrogen attained over 95% of the theoretical densities.
Although as-sintered alloys consisted of tungsten-rich and chromium-rich coarse phases, after the sub-sequent anneal at 1200°C for 5 hrs these phases became fine and homogeneous.
In these dense alloys, an alloy containing 30% chromium showed good resistance to the oxidation in air in the range of temperature, 1000-1200°C.
