An Investigation on Dynamic Tensile Properties of TiAl Intermetallic Alloy

Abstract

ABSTRACTRoom-temperature tensile properties of polycrystalline Ti–;47A1–2Mn–;2Nb alloy with nearly lamellar (NL) microstructures were investigated at the strain rates between 10-;5 and 1000 s-1 using a self-designed Split-Hopkinson tensile bar setup with a rotating disk and conventional testing machine. It was found that tensile ductility varies within a narrow range with the strain rate while dynamic strengths (σd) of the alloy are obviously higher than static strengths (σs). There exists a linear relationship between σs and the logarithm of the strain rate , and between σ d and the strain rate itself (). Fractography analysis indicated that the alloy fractured in a mixed mode of predominant transgranular cleavage and minor intergranular cracking under static and dynamic strain rates. Environmental effect was excluded from the main cause for the room-temperature brittleness of the investigated alloy.