Crystallographic texture evolution and tribological behavior of machined surface layer in orthogonal cutting of Ti-6Al-4V alloy

Abstract

The machining-induced crystallographic orientation variation in the plastic deformation layer on the mesoscopic scale usually occurs when severe plastic deformation undergoes in the machined surface layer, which will further affect the macroscopic mechanical performance of the machined parts. The orthogonal cutting experiments of Ti-6Al-4 V titanium alloy were carried out to confirm the effectiveness and reliability of the established finite element method (FEM) simulation cutting model with ABAQUS. From the perspective of macroscopic deformation, the shear strain and strain rate history were obtained, and this provided the fundamental data to simulate the machining-induced surface crystallographic texture evolution process using a visco-plastic self-consistent (VPSC) code. The pole figures and orientation distribution function (ODF) maps of crystallographic texture were produced and analyzed using a toolbox of Matlab. In order to validate the existence of crystallographic texture orientation with anisotropy, friction and wear tests were performed to explore the influence of crystallographic texture variation on the macroscopic properties of machined surface. The difference of friction coefficients and wear track width in the cutting direction and vertical cutting direction confirmed the hypothesis, and the machining-induced crystallographic texture evolution will alter the surface integrity and eventually the mechanical behavior of machined parts. Keywords: Crystallographic texture evolution, Titanium alloy, Machined surface, Shear texture, Friction property, Anisotropy