Cyclic Stress Response Behavior of Near β Titanium Alloy and Deformation Mechanism Associated with Precipitated Phase

Siqian Zhang,Haoyu Zhang,Jing Liu,Jie Sun,Lijia Chen,Junhong Hao

doi:10.3390/met10111482

Siqian Zhang, Haoyu Zhang + Show 4 more

Open Access

https://doi.org/10.3390/met10111482

Copy DOI

Abstract

The cyclic stress response behavior of Ti-3Al-8V-6Cr-4Mo-4Zr alloy with three different microstructures has been systematically studied. The cyclic stress response was highly related to the applied strain amplitude and precipitated phase. At low strain amplitude, the plastic deformation was mainly restricted to soft α phase, and a significant cyclic saturation stage was shown until fracture for all three alloys. At high strain amplitude, three alloys all displayed an initial striking cyclic softening. However, the softening mechanism was obviously difference. Interestingly, a significant cyclic saturation stage was noticed after an initial cyclic softening for alloy aging for 12 h, which could be attributed to the deformation of {332}<113> twin and precipitation of α″ martensite.

Highlights

Near β titanium alloys are extensively used in industry due to their high specific strength, adequate ductility, fracture toughness, biocompatibility and excellent corrosion resistance [1,2,3]
The cyclic stress response behavior of titanium alloys tends to be remarkably complex, which is highly dependent on the test temperature, applied plastic strain amplitude, strain rate, microstructure and so on [8,9,10,11]
An obvious cyclic saturation stage is noticed after an initial cyclic softening until fracture

Summary

Introduction

Near β titanium alloys are extensively used in industry due to their high specific strength, adequate ductility, fracture toughness, biocompatibility and excellent corrosion resistance [1,2,3]. As titanium alloys are cyclically strained during fatigue, the response stresses generally show an increase or a decrease as the number of cycles increases, which is termed cyclic hardening or cyclic softening, respectively. The cyclic stress response behavior of titanium alloys tends to be remarkably complex, which is highly dependent on the test temperature, applied plastic strain amplitude, strain rate, microstructure and so on [8,9,10,11]. It may display an initial cyclic hardening, an obvious softening, and a saturation stage is reached. An obvious cyclic saturation stage is noticed after an initial cyclic softening until fracture

Methods

Discussion

Conclusion