Abstract
Partial pressures of the gases evolved during vacuum sintering or degassing treatment of some alloy powders were measured by use of a mass-spectral analyser. A mixture of tungsten carbide and cobalt, water- and gas-atomized high speed steel powders, powdery carbonyl nickel, tungsten and zirconium hydride were respectively heated in a vacuum, the extracted gases being analysed stepwise at temperatures up to 1000°C.
The distinctive features in the results are as follows:
(1) WC-Co compacts and high speed steel powders evolve carbon dioxide at 300-600°C, and carbon manoxide at 500-1000°C.
(2) Carbonyl nickel noticeably evolves carbon dioxide.
