Strain Rate Sensitivity of Tensile Properties in Ti-6.6Al-3.3Mo-1.8Zr-0.29Si Alloy: Experiments and Constitutive Modeling.

Jun Zhang,Bin Zhang,Junhong Chen,Peng Wang,Hanjun Huang,Yang Wang

doi:10.3390/ma11091591

Abstract

The complex deformation usually involves wide strain-rate change. However, few efforts have been devoted to investigate the effect of strain rate history on the tensile behavior of α + β titanium alloy. In present paper, tensile tests of Ti-6.6Al-3.3Mo-1.8Zr-0.29Si alloy were carried out under both constant and variable strain-rate conditions within the region from 10−3~500 s−1. A single stress pulse experimental technique was utilized to conduct the recovery tests. The strain-rate history effect was examined. It is found that the flow stress is independent on the strain rate history, though the alloy exhibits obvious positive strain rate sensitivity. The Taylor-Quinney coefficient of the plastic work converted to heat is proved as 0.9 at high strain rates. The cavitation fracture mechanism is revealed by microstructural observation over the full range explored. In basis of the experimental results and other pulished literatures, empirical Khan-Huang-Liang constitutive model was suitably modified to account for the strain-rate dependent behavior. Good agreement is achieved between the modeling prediction results and experimental data.

Highlights

The complex deformation usually involves wide strain-rate change
Few efforts have been devoted to study the tensile behavior of titanium alloy at high strain rates, despite the fact that tension-compression asymmetry has been found in the stress-strain responses and failure mechanism of α and α + β type titanium alloys [17,18,19]
The conclusions were drawn as follows: (1) An increase of flow stress is observed under the variable strain-rate loading from 10−3 s−1 to 500 s−1, (1) indicating

Summary

Introduction

The complex deformation usually involves wide strain-rate change. few efforts have been devoted to investigate the effect of strain rate history on the tensile behavior of α + β titanium alloy. Considerable efforts have been devoted to acknowledge the rate-effect on the dynamic responses of Ti-6Al-4V alloy which has been most widely used α+β titanium alloy [10,11,12,13,14,15,16] These studies have demonstrated that strain rate has great influence on the compressive behavior of titanium alloy. Few efforts have been devoted to study the tensile behavior of titanium alloy at high strain rates, despite the fact that tension-compression asymmetry has been found in the stress-strain responses and failure mechanism of α and α + β type titanium alloys [17,18,19]. There should be a continuous temperature rise in the specimen generated from the plastic work It is of great significance for the accurate description of mechanical behavior to evaluate effect of the adiabatic temperature on the flow stress

Objectives

Methods

Conclusion