Comparative Study of Aluminium—Alumina Composite Prepared by Mechanical Mixing and Oxidation

The present investigation is aimed towards comparatively study the mechanical and corrosion resistance properties of aluminium-alumina metal matrix composites (AAMMCs) prepared by two different routes. In one route, different weight percent of commercially pure aluminium and alumina powders were mechanically blended and compacted at uniform pressure of 10 ton/inch² followed by sintering at different temperatures for specific time duration. In another route, commercially pure aluminium powders were oxidized at four different temperatures (500–800 \(^\circ{\rm C}\)) for three different time durations (15, 30 and 45 min) followed by blending of oxidized Al powder, compacting and sintering of composite samples. Scanning electron microscopy (SEM) images of blended powders were taken for confirming the uniform distribution of Al₂O₃ particle in Al matrix. Mechanical properties like hardness, wear resistance and chemical properties like corrosion resistance of AAMMCs were measured. It is observed that both mechanical properties and corrosion resistance of pure aluminium can be enhanced by preparing AAMMCs, whereas more enhancements can be achieved by oxidation route compared to mechanical mixing route of composites preparation. Therefore, the novelty of the present research work is to enhance the mechanical properties and corrosion resistance of aluminium by preparing AAMMCs without addition of Al₂O₃ in Al powder matrix material, i.e. following oxidation route of composite preparation. It is also observed that the mechanical properties and corrosion resistance of Al-Al₂O₃ composites increases with increase of weight percent alumina added, sintering temperature, oxidation temperature and oxidation time duration individually.