Surface Covering Effects of Mg Alloys with Al<sub>2</sub>O<sub>3</sub> Particle Dispersed Mg Powders Using MM/SPS Method

To modify the surface of practical Mg alloy M1A, M1A laminated compacts were produced by laminating 20vol% Al2O3 particle-dispersed Mg mechanical milling (MM) powder (20vol% powder), which has higher hardness than practical Mg alloys, on both surfaces of M1A discs and then spark plasma sintering (SPS) treatment. The results of micro-Vickers hardness tests and wear tests of the M1A laminated compacts showed that the surface coating layer (20vol% layer) had higher hardness, lubricity and wear resistance than the M1A surface, and from optical microscopy lateral observations of the M1A laminated compacts broken by a three-point bending test, the 20vol% layer / M1A interface was found to be highly adherent. Elemental analysis by SEM-EDS and X-ray diffraction results identified the precipitates at the interface as Mn-Al intermetallic compounds. The relationship between the sintering time and the interfacial adhesion suggests that the interfacial adhesion is influenced by the amount of Al diffusion from the 20vol% layer to the M1A disc rather than the formation of Mn-Al intermetallic compounds at the interface.