An investigation of dynamic mechanical behaviour of Ti6Al4V titanium alloy at room temperature

Chun Ran,Baoqiao Guo,Ling Li,Haibo Liu,Pengwan Chen,D Zhang,G Cui,H Ding,B Zi

doi:10.1051/matecconf/20167703002

Abstract

To study the high strain rate shear behaviour of Ti6Al4V titanium alloy, a series of dynamic compression experiments has been performed by split Hopkinson pressure bar (SHPB) using Flat Hat-shaped specimen at room temperature. Macro true shear stress-true strain curves were obtained under different strain rate loading conditions at room temperature. The effects of strain hardening and strain rate hardening on the dynamic mechanical properties of Ti6Al4V titanium alloy were discussed. Results indicate that a) The higher the strain rate, the higher the flow stress, therefore, the material has obvious strain rate hardening effect, b) It is ductile failure for Ti6Al4V titanium alloy under quasi-static loading condition, c) For dynamical tests, the values for true shear stress increase with increasing true strain till the maximum true shear stress, on the contrary, the values for true shear stress decrease with increasing the true strain after the maximum true shear stress and d) The flow stress increases with increasing the true strain under quasi-static loading condition during the plastic deformation.

Highlights

Ti–6Al–4V, an α+β titanium alloy, is world widely used to manufacture the engine fan and blade in aerospace industries due to its highly attractive material parameters, such as low mass density, high strength and high temperature stability ([1])
To reduce edge effect and measure the temperature rise during the deformation, the Flat Hat-shaped (FHS) specimen was designed by Clos ([16, [17])
The true shear stress-true strain can be calculated based on eqs.(2)-(6)

Summary

Introduction

Ti–6Al–4V, an α+β titanium alloy, is world widely used to manufacture the engine fan and blade in aerospace industries due to its highly attractive material parameters, such as low mass density, high strength and high temperature stability ([1]). A profusion of studies on the dynamic mechanical behaviour of titanium and titanium alloys have been carried out ([2]). Chichili et al ([3]) and Dong et al ([4], [5]) investigated dynamic mechanical behaviour of α-Ti at room temperature by using split Hopkinson pressure bar (SHPB) and found that the strain hardening is strain rate and temperature dependence. Hat-shaped (HS) specimen was invented in 1977 by Hartmann and Meyer at the Fraunhofer Institute (IFAM, Bremen, Germany). Due to the unique geometry of HS specimen, extremely high strains at high strain-rate can be reached. To reduce edge effect and measure the temperature rise during the deformation, the Flat Hat-shaped (FHS) specimen was designed by Clos ([16, [17])

Objectives

Results

Conclusion