Effect of micro-texture and orientation incompatibility on the mechanical properties of Ti60 alloy

Abstract

In this work, the effects of no-micro-texture regions (no-MTR, weak texture) and strong-MTR on the mechanical properties of Ti60 alloy engine blisk materials were investigated. It has been shown that MTR has a small effect on the room temperature strength of the alloy, but strongly affects plasticity, which reaches 18.5% for no-MTR alloy is twice as high as for MTR alloy. In contrast to no-MTR alloys, MTR alloys have only two-stage strain hardening behavior and fracture before meeting the instability criterion. Based on digital image correlation (DIC), high-resolution DIC and in-situ tensile analyses show that no-MTR alloys produce more uniform strains in deformation than MTR alloy. MTR exacerbates the slip deformation and local strain inhomogeneity in the hardening stage. Prevent premature fracture by eliminating MTR, thereby substantially increasing no-MTR alloy plasticity and triggering excellent work-hardening ability due to the uniformity of local deformation and dislocation multiplication. Meanwhile, the unique deformation characteristics of the combination of (0001) and (10 1‾ 0) soft orientations are proposed and elucidated. The incompatibility of the two orientations causes stronger slip deformation incompatibility, resulting in local strains and dislocation slips clustered mainly at the grain or MTR boundaries of the (0001) and (101‾ 0) soft orientation features, which further exacerbates the alloy failure at the microscopic level.