Effect of Solution Temperature on Grain Size in a Mg-4Y-3Nd-3Dy-0.5Zr Alloy

The effects of solution treatment on the grain size and microstructures of an Mg-4Y-3Nd-3Nd-0.5Zr alloy were investigated. Grain size increased slowly when treated at 500 oC and 525 oC, showing that the hindering effect of eutectic phase on grain growth can be ignored. The fitting relationship equations for average grain size vs. solution time h are =49.92t0.15 and =45.44t0.15, respectively. When the solution temperature was increased to 550 oC, the fine dispersion phases was dissolved gradually, leading to a rapidly increase in grain size. The fitting relationship equations for vs. h is=39.69t049. The grain growth exponent n at 550 oC is far higher than those at 500 oC and 525 oC.