2003 Volume 44 Issue 12 Pages 2468-2474
To realize the lightweight effects by materials technology, a new process for fabricating high-performance magnesium composites via a solid-state reaction by using high purity SiO2 glass scraps has been established. From a viewpoint of the microstructures control of the composites, the core technologies to improve the physical and mechanical properties are; a solid-state synthesis of Mg2Si and MgO particles by the deoxidization of SiO2 glass by magnesium, and a refinement of both their dispersoids and the magnesium matrix grains by the RPW process. For example, when using the elemental AZ31 magnesium alloy and 2 mass% SiO2 glass powder mixture as starting raw materials, the hot extruded composite including Mg2Si and MgO shows 363 MPa of the ultimate tensile strength. The addition of only 2 mass% SiO2 powder also causes the remarkable improvement of the corrosion resistance because of the uniform distribution of refined Mg2Si not only at the particle boundary but also inside the grains. This process is quite safety and environmentally benign compared to the conventional re-melting process, because of utilizing course magnesium raw powder and no use of SF6 toxic gas. It also shows a possibility to employ SiO2 glass scraps as starting raw materials to fabricate magnesium alloys.