Microstructure and deformation behaviour of the ECAP Al-Mn-Sc-Zr alloy

Abstract

The Al-Mn alloy stabilized by the addition of Sc and Zr was subjected to equal-channel angular pressing (ECAP) at room temperature. The microstructure evolution as a function of the number of ECAP passes was studied by transmission electron microscopy. The room temperature strength was characterized by microhardness measurements and tensile tests. The stability of the very fine-grained microstructure and strength characteristics were studied at elevated temperatures. Due to a good microstructure stability even after annealing at 500°C the possibility of superplastic behaviour was tested. The value of the strain rate sensitivity parameter m exceeding the bottom limit of superplastic behaviour was found.