MANUFACTURE OF POWDER OF CARBIDE IN SOLID SOLUTION STATE

摘要

PURPOSE:To obtain easily stable fine-grained W and Cr carbide powder in the form of solid solution by adding Cr or a Cr compound to WO3, melting them, spraying the melt on a cooling body, solidifying it by rapid cooling, and heat treating the resulting material in a carbonizing atmosphere while reducing it. CONSTITUTION:Cr2O3, other Cr compound or metallic Cr is added to WO3 and melted. The molten oxide is sprayed on a rotating cooling body or the like and rapidly cooled at =104 deg.C/sec cooling rate. The resulting dissolved oxide is heated to =1,100 deg.C in an atmosphere of a gaseous mixture consisting of H2 and CH4 in 1/10-100/1 ratio. It is preferable to generate plasma in the atmosphere by applying electric energy from the outside and to evacuate the atmosphere to 0.1-20Torr. Stable fine-grained carbide powder of W and Cr in the solid solution state having =about 1.0mum grain size can be manufactured with high productivity enabling mass production.