Amplitude Dependence of Dynamic Young's Modulus of CuZnAl Alloys near Martensitic Transformation

Abstract

The dynamic Young's modulus E of CuZnAl alloys displays non-linear behaviour in the vicinity of the martensitic transition as it decreases with increasing the amplitude of vibration.The difference AE between the Young's modulus measured at the lowest strain e0 and that at the current strain e shows a double peak in the transition region, both during heating and cooling.These peaks are believed to be associated with some lattice instabilities such as those leading from the austenitic β1 and β2 phases to the β’1 and β’2 martensites, respectively.The observed elastic non-linearity appears to be a bulk lattice effect.as it occurs even over temperature regions far above Ms’ where the system is a homogeneous single phase.