A comprehensive method for selecting cutting tool materials

Although there are many types of cutting tool materials, no single cutting tool material meets all the needs of machining applications because of the complex and changeable cutting conditions. It is crucial to study the matching between tool materials and workpiece materials for improving productivity, obtaining good surface quality and reducing machining cost. In this paper, rule-based reasoning (RBR) method and gray complex proportional assessment (COPRAS-G) method are applied to solve the problem of cutting tool material selection. RBR is used for primary selection of tool materials to reduce the number of alternatives and the computational complexity in COPRAS-G method. Ten attributes of tool materials including physical, mechanical, chemical, and cost parameters are selected as criteria in the COPRAS-G method, and entropy method and analytic hierarchy process (AHP) are used to determine the objective weights and subjective weights of attributes, respectively. Finally, the ranking of several alternatives is obtained to select the most suitable cutting tool material. Taking the cutting tool material selection of machining CGI as an example to validate the method proposed in this paper. The research results revealed that the alumina ceramic has the best comprehensive performance, alumina ceramic cutting tools containing carbides to improve the flexural strength and fracture toughness, or cemented carbide cutting tools with alumina coating are preferred for machining CGI. High-speed milling experiments of CGI were carried out, and the results showed that the alumina-coated tungsten carbide tools had longer tool life than the silicon nitride ceramic tools, which confirmed the effectiveness of the proposed cutting tool material selection method. And this method can be extended to other engineering applications in material selection problems.