Tool determination and geometry parameter optimization of carbide tool in high-speed milling of third-generation γ-TiAl alloy

Abstract

Gamma titanium aluminide alloys (γ-TiAl) are widely recognized as potential replacement for nickel-based superalloys in aerospace. However, along with brittleness at room temperature, poor surface quality and sever tool wear undermine their machinability, so that γ-TiAl alloy is considered as a typical intractable material. Tool selection and geometry optimization are encouraging strategies to improve the machinability of this kind of material. In this work, the cutting performance of six carbide grade tools is compared. And the cutting force, surface roughness and tool wear are selected as the evaluation criterion for the tool material determination. Then, the effects of tool geometry parameters including rake angle, primary relief angle and helix angle on surface roughness and tool wear are further studied. The sample dataset is utilized to formulate the first-order model with interaction. The predicted results of these models accorded well with the measured results. Due to the multi-performance characteristics, grey relational analysis method is introduced into the optimization of tool geometry parameters. The analysis of variance is employed to identify the most significant factor. And then, the confirmation test showed the improvement of the multi-performance characteristics.