Fabrication, Structure, Properties and Application of Gradient Sintered Carbide-Steels with HS6-5-2 Matrix

摘要: This chapter presents essential information concerning sintered tool materials containing carbides, id est high-speed steels and metal matrix composites, including sintered carbides and carbide steels. Gradient materials, whose properties change gradually according to their volume, are characterised. The results of investigations are presented in the final part into the structure and properties of newly developed sintered graded tool materials fabricated by the conventional metallurgy method from a mixture of high-speed HS6-5-2 steel powder and WC carbides. Investigations are described for four-layer materials, where the successive transition layers with a smaller and smaller volume fraction of tungsten carbide were constituted from the surface layer side, until a substrate layer containing high-speed HS6-5-2 steel only. The outcomes are described of structural examinations in a scanning and transmission electron microscope, an X-ray microanalysis and the results of density, porosity and hardness examinations of sintered gradient materials and the results of structure and hardness examinations of heat-treated materials.