Effect of Post-HPT Heat Treatment on the Mechanical Performance in Ti/Cu-Cr/S20C Clad Materials

Abstract

In this study Ti/Cu-Cr/S20C were clad by High Press Torsioning(HPT) and the effect of post-HPT heat treatment on the interfacial reaction products and the mechanical performance in Ti/CuCr/S20C clad material were studied. No cracks were observed to be emanated from the corner of the indentation mark on the intremetallic compound layer at the Ti/Cu-Cr interface, suggesting those intermetallic compounds is not so brittle. The stress-strain curves exhibited three steps in as-HPTed clad samples and those heat-treated at 500°C for 1hr. Step-wise fracture occurred in the sequence of S20C, Cu-Cr and Ti with each fracture resulting in the sudden drop of the stress. The stress-strain curves exhibited two steps in clad metals annealed at 600°C for 1hr, with first step corresponding to the fracture of S20C plate and the second one corresponding to the concurrent fracture of Ti and Cu-Cr plates. Ti/Cu-Cr/S20C heat-treated at 600°C for 24hrs exhibited just one step final fracture, suggesting that the bonding strengths are high enough to resist the localized strain concentration at the interfaces.