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

In this study a two-phase gamma-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 2x10(-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. (C) 2000 Elsevier Science Ltd. All rights reserved.