Constitutive Equation for V–5Cr–5Ti at High Temperatures Measured Using the SHPB Technique

Abstract

A high temperature split Hopkinson pressure bar (SHPB) test system is used to investigate the effects of temperature as well as those of strain and strain-rate. Effects of temperature for the vanadium alloy (V-5Cr-5Ti) are investigated by developing a high temperature SHPB test system. In this work, high temperatures greater than 1100°C are attained in the SHPB test specimens by using a synchronically assembled heating system .When testing with the high-temperature SHPB apparatus, care is required to prevent oxidation of the surface of the specimen, and to prevent an inhomogeneous temperature distribution from developing in the specimen. To determine the true flow stress–true strain relationship, specimens are tested from 15°C to 1100°C and at a strain-rate of about 3000 s-1: The parameters for a Johnson–Cook constitutive equation is determined from the test results. The Johnson–Cook constitutive equation is suitable for expressing the dynamic behavior of the V-5Cr-5Ti vanadium alloy.