Microstructure and anisotropy of mechanical properties in ring rolled AZ80-Ag alloy

Abstract

The microstructure, anisotropy in tensile strength and tensile creep resistance of the ring rolled AZ80-Ag alloy were studied. The ring exhibited higher strength along rolling direction (RD) than transverse direction (TD). The microstructure characterization and texture analysis demonstrated that the tilted basal texture was responsible for the higher tensile performance along RD. Investigations on the creep anisotropy revealed that the samples along RD had lower creep resistance, higher creep strain and higher steady creep rate at 70–80 MPa, compared with that along TD. The nominal creep stress exponent (n) values, 1.13 for RD and 3.86 for TD, indicated that diffusional creep and dislocation climb were the two corresponding creep mechanisms. During creep of the alloy, Mg₁₇Al₁₂ phase discontinuous precipitations were witnessed and their volume fraction enhanced with increasing stress.

Keywords

creep / anisotropy / precipitation / ring rolling / magnesium alloy

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