Mechanical Properties of an Al-Mg-Sc Alloy Subjected to Intense Plastic Straining

Abstract

Effect of intense plastic straining on rollability and service properties of an Al-6%Mg-0.3%Sc alloy was examined. Ultrafine-grained structure (UFG) was produced by equal-channel angular pressing (ECAP) to a strain of 8 at a temperature of 325oC. The formation of UFG structure resulted in increase in the yield stress from 223 MPa to 285 MPa and ultimate stress from 350 MPa to 389 MPa in comparison with initial hot extruded condition. Total elongation slightly decreased from 33% to 29%. After ECAP, the material was subjected to cold and isothermal warm rolling. The formation of UFG structure resulted in enhanced rollability of the present alloy at room temperature. Cold rolling with high reduction provides the development of heavily deformed microstructure with high dislocation density, while the isothermal warm rolling does not remarkably affect the microstructure produced by ECAP. The mechanical properties after ECAP and ECAP with subsequent isothermal rolling were roughly similar. In contrast, cold rolling to the same strain resulted in significant increase of yield stress (495 MPa) and ultimate stress (536 MPa). Total elongation attained was 13%.