2003 年 44 巻 4 号 p. 440-444
The Mg97Zn1Y2 bulk alloy has been produced by MA-HDH P/M process using MgH2 powders as the starting material. As-extruded Mg97Zn1Y2 bulk alloy of MAed powders showed a high compressive yield strength of 616 MPa and a plastic strain of 4.2%. These values were much higher than those of commercial ingot metallurgy (I/M) Mg alloys, such as AZ91 and ZK60. This is originated from the refinement of hcp-Mg grains, the solid solution hardening of Zn and Y, and the dispersion hardening by MgO and Y2O3 fine particles. No degradation was observed in mechanical properties of the alloy even after annealing at 673 K for prolonging time. This is considered to be due to the inhibition of the hcp-Mg grain growth by the densely dispersed MgO and Y2O3 fine particles. Therefore, MA-HDH P/M Mg97Zn1Y2 alloy is promising as the structural material for high temperature applications.
