Study on Hot Working Characteristics and Deformation Response of as Cast AZ91 Mg Alloys

Abstract

The deformation response of magnesium alloy AZ91 was investigated by means of hot compression tests. The flow curves were obtained in the temperature and strain rate range of 300–500°C and 0.001–1 s^-1, respectively. The processing maps of the studied material were obtained by interpreting them on the basis of the dynamic material model. The activation energy maps were developed based on Lyapounov’s function and the safe processing zones were confirmed by comparing both the maps taking into account the largely accepted conclusions in the form of the constitutive equation that correlates flow stress, strain rate, and temperature in these materials. The flow instability between strain rates 0.31–1.0 s^-1and temperature range between 300 and 480°C were studied. The optimum domains and instability zone were obtained for the hot workability of the material.