Calciothermic powders of rare metals and intermetallic compounds

Abstract

This paper presents a profound review of scientific and technical literature on the issues of calciothermic production of powders of rare metals, intermetallic compounds, composite materials and refractory oxygen-free compounds (carbides, nitrides). Calciothermic reduction is a metallothermic synthesis method for those substances where calcium or its derivatives, such as calcium hydride or calcium carbide, are used as a reducing agent. Thermodynamics aspects of a reduction process are covered in the paper broadly, with particular emphasis on assessing the reduction depth of original oxide raw materials, as TiO2. The mechanism and kinetics of calciothermic synthesis of single-component and multi-component alloys are described. Presented are both technological means of obtaining materials and hardware resources of many varieties of calciothermic method. The key features of the work are generalization and systematization of properties (chemical, physical, technological) of materials synthesized by calciothermic method. The data are accumulated in the appropriate tables and divided by substance classes (powders of metals and alloys, powders of intermetallic compounds, powders of carbides, powders of nitrides, and powders of composite materials). Methods of calciothermic powder making in case of the singlecomponent and complex multi-component systems are briefly described. This work will be interesting to the students of metallurgical profile and specialists whose scientific interests are in the field of material synthesis by methods of powder metallurgy.