Mechanical properties of Al–Mg alloys with equiaxed grain structure produced by friction stir processing

Abstract

The equiaxed grain structure binary Al–Mg alloys with different Mg contents and grain sizes were fabricated by friction stir processing (FSP). The fine grain-structured Al–Mg alloy with high Mg content exhibited higher strength than other FSP alloys because of its higher grain boundary, dislocation, and solution-strengthening effects. The ductility of the equiaxed grain structure Al–Mg alloys also increased with increasing Mg content and decreasing grain size. The work hardening rate and stress distribution of the Al–Mg alloys during tensile process could be improved by the high amount of Mg solution atoms and fine equiaxed grain structure. Thus, the yield strength, ultimate strength, uniform elongation, and total elongation of the Al–6.8 Mg with fine equiaxed grain structure could reach 188 MPa, 341 MPa, 30%, and 35%, respectively.