Optimal selection of cutting tool materials based on multi-criteria decision-making methods in machining Al-Si piston alloy

Abstract

Cutting tools are the executor and core element of machining, and tool materials are of decisive significance for the development of high-speed machining technology. For a particular workpiece material, to select the appropriate tool material is an important prerequisite to increase the machining productivity and to improve the machined surface quality. In this paper, a compromised weighting method composed of the subjective judgment method and the objective judgment method was utilized to conduct criterion weighting in the cutting tool material selection when machining Al-Si piston alloy. The analytic hierarchy process (AHP) method was used to subjectively judge the significance of the material properties and determine their criterion weight, while the entropy weight method was adopted to objectively judge the significance and determine their weight values. The synthesis weights of the material properties were determined by the comprehensive assessment of both the AHP and entropy methods, and the synthesis scores of the different tool material candidates were obtained. Results revealed that PCD was found as best materials for Al-Si piston alloy machining, and YG8 is slightly more suitable than YG6X for machining Al-Si piston alloy. In short, the qualitative problems in tool material selection were realized systematically and hierarchically by quantitative calculation and analysis. This provides a new thinking in tool material selection for high-efficiency machining of difficult-to-machine materials.