Dynamic Behavior in Ti-5553 Alloy with β Phase under Compression Loading

Abstract

In this paper, the shock phase transformation of β phase in Ti-5Al-5Mo-5V-3Cr-0.5Fe (Ti-5553) was investigated. Split Hopkinson Pressure Bar (SHPB) and light gas gun were employed to investigate the dynamic properties under high strain rates from 1000s-1to 3500s-1. Microstructure characterization was carried out by optical microscopy (OM), scanning electronic microscopy (SEM) and transmission electron microscope (TEM). The experimental results demonstrate that the Ti-5553 alloy with β phase exhibit no obvious strain rate hardening effect with the high strain rate from 1000s-1to 3000s-1. However, compared with the quasi-static compression test results (10-3s-1), this alloy shows an evident strain rate hardening effect, with the yield strength significantly improved. Second time loading indicates light gas gun dynamic tensile loading and then SHPB dynamic compression loading in Ti-5553 alloy with β phase. The results show that the shock-induced β to αʺ martensite phase transformation dramatically influences the postshock mechanical properties of these alloys. The yield strength of this alloy decreased after the shock wave effect of light gas gun, its ductility increasing. Higher shock pressures yielded an increased dislocation density and a gradual increase in the yield strength. Adiabatic shear band (ASB) exists in second time loading Ti-5553 alloy under 103s-1strain rate. SHPB loaded the alloy: The results show that the Ti5553 alloy with β phase is adiabatic shear failure in high strain rate (3000s-1).