Solid State Reaction in Mechanically Alloyed Magnesium with Addition of Low-Melting-Metal Oxides

摘要

Pure magnesium powders were mechanically alloyed powders of low-melting-metal oxides (SnO_2, PbO and Sb_2O_3) by using a planetary ball mill under an Ar atmosphere. After mechanical alloying, the powders were consolidated to the P/M materials by vacuum hot pressing. Solid state reaction in the mechanically alloyed powders and the P/M materials was studied by XRD and DSC. In these systems, the solid state reaction started to occur during MA processing between Mg and low-melting-metal oxides. The added low-melting metal oxides decomposed and formation of MgO and intermetallic compounds (Mg_2Sn, Mg_2Pb, Mg_3Sb_2) occurred. Such solid state reaction further progressed during hot-pressing and subsequent heat treatment. Microstructures were studied by TEM and mechanical strength was discussed by hardness values for both MA powders and P/M materials.