Research Of Nano-Al₂O₃Particles Reinforced Aluminum Matrix Composites Preparation

Al2O3particles reinforced aluminum matrix (Al2O3/Al) composites compared to aluminum in strength, hardness, wear resistance, high temperature creep resistance has been greatly improved. While the size of Al2O3particle is reduced to the nanoscale, Al2O3/Al composite materials will not only retain the original properties, but also showed good toughness, superplastic properties. It has a broad application prospects in the automotive, aerospace, military and other fields,α-Al2O3and γ-Al2O3particles of30nm were selected as reinforcement, and A356aluminum alloy was selected as the matrix. Nano-Al2O3/Al composites were fabricated by immersing block-stirring casting method and orthogonal experiment. Microstructure, morphology, phase composition and interface structure were investigated by using of metallurgical microscope, JSM-7001F field emission scanning electron microscopy, X-ray diffraction, JEM-2100F field emission transmission electron microscopy; the hardness and corrosion resistance of the composites were tested by TH300Rockwell hardness tester and ZENNIUM electrochemical workstation. Investigated the effects of different stirring speed, stirring time and particle content on the microstructure and properties of the composites through the above experimental results.Orthogonal experimental results show that, at a stirring speed of600r/min, stirring for50min and the particle content of3%of the fabrication, α-Al2O3/Al composites will obtain a uniform dispersion of particles, hardness and corrosion resistance are improved; while for γ-Al2O3/Al composites, the best fabricate process is at the stirring speed of600r/min, stirring for10min, the particle content of1%. γ-Al2O3/Al composite with less stirring time, less content of the particles will be able to achieve the desired combined effect compared to α-Al2O3/Al composite. Respectively, the phase analysis of composites with optimal fabrication showed that the composites contain Al, Si. and Al2O3. The interface analysis showed that the composite constitute a coherent interface between the Al2O3and Al interface.