The effect of heat treatment on the tensileand creep behaviour of “neat” matrix Ti-22Al-23Nb

Abstract

A study has been conducted to examine the effect of post-consolidation heat treatment on the longitudinal tensile and creep properties of an orthorhombic-based titanium aluminide, Ti-22Al-23Nb (a%), in neat matrix form. Heat-treatment parameters were selected such that they would be consistent with future inclusion into the consolidation cycle for the fabrication of continuously reinforced orthorhombic titanium matrix composites (O TMCs). The effects of heat treatment on microstructural evolution, including type and morphology of the phase constituents, was examined via scanning secondary electron microscopy and quantitative image analysis. Variations in microstructural features were correlated with resulting room-temperature tensile properties including: ultimate tensile strength, yield strength, total elongation and modulus, as well as isothermal creep response at 650°C/172 MPa.