Fabrication and mechanical properties of metal matrix composite in Mg-Al-B4C Systems

Mg is the lightest practical metallic materials, which has specific gravity of 1.74 g/cm3 and is excellent in specific strength. In this study, the powder metallurgy method was applied to make the particle-dispersed composite material with the addition of B4C in Mg-Al by. The effect of manufacturing conditions on the structures and mechanical properties of the sintered body was investigated how to exert its high strength and high functionality as an alloy. The sample composition of Mg-9 %Al and (Mg-9 %Al)13 %B4C was produced by hot pressing and pressureless resintering. Sintering temperature of 415 °C or 475 °C was adopted as for the hot press, and with the sintering temperature controlled at some temperatures between 500..700 °C. And, some samples were mechanical alloyed. The new alloy we made has following appearances and performances; (1) High strength was exerted by addition of B4C as the reinforcing particles. (2) Mechanical alloyed (Mg-9 %Al)13 %B4C made by the hot pressed at 475 °C and followed by resintered at 560 °C, showed bending strength of 603 MPa and Rockwell hardness of 100.6 HRH.