The influence of microstructural and physical properties on wear mechanism of cemented carbides

A comparative analysis of three different cemented carbide tool materials was made for their microstructure, hardness and fracture toughness. The microstructure of cemented carbides were examined in terms of carbide grain size, carbide grain distribution and cobalt layer thickness. The fracture toughness was measured using Palmqvist technique which involved interpretation of toughness of hard metals in terms of crack length created by a Vicker hardness tester. The three different cemented carbide materials were ranked in terms of their physical and mechanical properties. The physical and mechanical properties were correlated to the wear mechanisms by independent sliding tests. The sliding tests were performed using a pin on disk machine, lathe and machine center. These tests allowed the materials to be ranked in terms of wear resistance when rubbed against carbon fibre composite. The wear resistance was correlated to the material properties of the test specimen to determine the best carbide materials for machining carbon fibre composites. (author)