Mechanisms of action of different alloy elements for adiabatic shearing sensitivity of titanium alloy

Abstract

The cutting experiments were conducted for the industrial pure titanium (TA2) and titanium alloy (TC4) under the same cutting condition to obtain the chips of different shapes. The mechanisms of action of different alloy elements for adiabatic shearing sensitivity were studied from the perspective of valence electron structure. The results show that the interface electron density and the lattice electron density are related to adiabatic shearing sensitivity. The bigger the interface electron density is, the higher the interfacial bonding strength, and the higher the adiabatic shearing sensitivity. Also, the lower the lattice electron density is, the lower the thermal conductivity, and the higher the adiabatic shearing sensitivity. For TA2, the electron density is smaller and the lattice electron density is higher, so its adiabatic shearing sensitivity is low. The shape of chip is approximate ribbon. For TC4, the bi-phase interfaces are caused, interface electron density is increased and the lattice electron density is decreased due to aluminum (Al) and titanium (Ti) addition, so its adiabatic shearing sensitivity is higher than that of TA2. The saw-tooth chip divided uniformly by Adiabatic Shear Band (ASB) was formed. The basis can be provided for optimizing process parameters and selecting materials with different cutting performance by studying the specific alloy elements on the influence of adiabatic shearing sensitivity to predict the chip morphology tosomeextent in valence electron structure level.