On the origin of acoustic emission during room temperature compressive deformation of a γ-TiAl based alloy

In this study a two-phase γ-TiAl based alloy with near gamma microstructure was deformed in uniaxial compression at room temperature. The deformation experiments were carried out at a strain rate of 2×10−4 s−1. The acoustic emission during deformation was monitored continuously using a root mean square voltmeter. Different annealing experiments between deformation cycles combined with transmission electron microscopy investigations revealed the formation of mechanical twins as the decisive mechanism for the acoustic emission.