Thermal fatigue testing of CuCrZr alloy for high temperature tooling applications

CuCrZr alloy offers good mechanical and thermal properties and was investigated in the present work for its potential as tooling material in thixoforming of steels. Samples of CuCrZr alloy were cycled thermally between 450 and 750 °C, every 60 s. The thermal conductivity of the CuCrZr alloy, nearly an order of magnitude higher with respect to that of the conventional hot work tool steel, proved to be very beneficial in terms of thermal stresses generated at the surface upon thermal cycling. The maximum compressive and tensile stresses produced at the front face of the CuCrZr alloy were estimated to be approximately 30 and 10 MPa, respectively, much smaller than those endured by the conventional hot work tool steel. The very favourable thermal stress state in the CuCrZr alloy die was largely negated, however, due to its inferior resistance to high temperature oxidation.