A brief discussion on the tensile creep deformation behaviour of wrought single-phase γ-TiAl

Abstract

Creep deformation behaviour in single phase γ-TiAl alloy has been an extensively studied topic since the late 1970 s. A lot of literatures have reported creep behaviour of γ-TiAl alloys, manufactured using different processing techniques [1], [2], [3], [4], [5], [6], [7]. The present discussion revisits the original work on understanding the tensile creep deformation behaviour of wrought single-phase γ-TiAl alloy by Hayes et al. [8] and is aimed to develop an understanding of steady state creep, through strain vs strain rate and strain vs ln(strain rate) plots. Besides, it also attempts to study the variation of stress exponent with temperature between 760 and 900⁰C and also, to determine activation energies using the two most common approaches, namely: Zener-Hollomon (Z-H) [9] and Sherby-Dorn (S-D, temperature compensated time approach) [10] for stress levels of 69.4 and 103.4 MPa between 760 and 900⁰C.