Effect of temperature on tensile properties of near-alpha alloy Timetal 834

Abstract

Tensile properties of titanium alloys are known to be strongly dependent on their microstructures and test conditions. Equiaxed alpha + beta microstructures offer high tensile strength and ductility, high resistance to fatigue crack nucleation and better LCF resistance as compared to the acicular microstructure. On the other hand, acicular microstructures exhibit better creep and fatigue crack propagation resistance and high fracture toughness. In general the flow stress decreases with rise in test temperature, however, under certain test conditions of temperature and strain rate, the flow stress shows a rising trend due to occurrence of the phenomenon of dynamic strain ageing (DSA). DSA was observed in the present investigation in various heat-treated conditions over a wide range of temperature from 623 to 823 K. In addition, a detailed account of the tensile behaviour of the alloy Timetal 834 both in the alpha + beta and beta treated conditions, over a wide range of temperature from 300 to 923 K has been discussed. (C) 2007 Elsevier B.V. All rights reserved.