Preparation And Properties Of Al₂O₃/Al Composites Sintered Under High Pressure

Particulate reinforced aluminum matrix composites, which process lightweight, high specific strength, high specific modulus and high wear resistance, are of extensive uses in aerospace, electronic and transportation industries.Particulate reinforced aluminum matrix composites with different content of alumina particle, were prepared with power metallurgy process under high pressure. And the microstructure and properties of the composites were investigated.The distribution of alumina particle and the grain size of aluminum were studied with the metalloscope. Vickers hardness tester was used to measure the vickers hardness. The tensile mechanic performance of the aluminum metal matrix composites was tested by the tensile testing machine. Fracture morphology of the aluminum metal matrix composites was observed with the field emission scanning electron microscopy. The CHI660A electrochemical workstation was adopted to measure the corrosion resistance. Results of the study show that: The vickers hardness of the composites enhanced obviously with the increase of the alumina particle compared with the matrix aluminum. The relative density of the composites reached over 98.5% . Tensile strength of the 5wt%Al₂O₃/Al composites increased obviously, the elongation rate decreased; tensile strength of the 10wt%Al₂O₃/Al composite had no distinguished improvement, as there were some Al₂O₃ particle gathered, material property deteriorated. The alumina particle mainly distributed on the edge of aluminium grain, and the aluminium grain increased as the temperature raised. Analysis of the fracture showed matrix was of ductile fracture, but at the place where Al₂O₃ particle gathered it was of brittle fracture. The polarization curve showed that corrosion resistance of the aluminum matrix composites was improved.