氧化铝增强铝基复合材料的微结构与性能研究

Microstructures and Properties of Alumina Reinforced Aluminum Matrix Composites

通过粉末冶金真空热压烧结法制备了不同Al_2O_3含量的氧化铝增强铝基复合材料,并利用X射线衍射、金相显微镜和扫描电子显微镜分析了微结构和微形貌对材料硬度的影响。结果表明,在Al_2O_3质量分数为1%~4%时,随着Al_2O_3含量增加,复合材料硬度呈现出先增加后降低的趋势。当Al_2O_3的质量分数为2%,烧结温度为400℃、压力为50 MPa时,复合材料的硬度最大,达到38. 7 HV。通过XRD图谱和金相组织图片可以发现,硬度提高的原因是Al_2O_3的加入可以细化Al基体的晶粒粒径和金相组织。

Alumina reinforced aluminum matrix composites with different Al2O3 content were prepared with powder metallurgy and vacuum hot pressing sintering. The effhcts of microstructure and morphology on hardness of the composites were analyzed by X-ray diffraction, metallographic microscope and scanning electron microscopy. The results showed that with the increase of Al2O3 ranging from 1% to 4%, the hardness of the composites increased firstly and then decreased. When Al2O3 remained 2%, the sintering temperature was 400 ℃ and the pressure was 50 MPa, the hardness of the composites reached the highest of 38.7 HV. It could be found in XRD patterns and metallographic pictures, the increasing hardness was attributed to the addition of Al2O3, which led to refining of the grain size and the microstructure of Al matrix.