Y2O3表面改性Al2O3P增强6061Al复合材料组织与性能

采用液相包裹法对Al₂O₃微粉进行稀土Y₂O₃表面改性,用挤压铸造法制备表面经稀土Y₂O₃改性的Al₂O_3P/6061Al复合材料,并对复合材料的显微组织及拉伸性能进行分析和研究。结果表明:表面经稀土Y₂O₃改性的Al₂O₃微粉能均匀的分布于基体中,界面润湿性得以改善,复合材料组织更加均匀。TEM观察表明:改性粉体在制备复合材料前后表面存在颗粒状包裹层。对其表面进行EDAX分析,结果显示含有Y,Al和O元素。粉体XRD图谱中有Y₂O₃衍射峰的存在。拉伸性能测试表明:改性粉体对Al合金增强效果明显增加,抗拉强度提高29.8％,屈服强度提高38.4％,延伸率提高10.3％。对拉伸断口进行SEM分析,改性后复合材料断口韧窝更加均匀、丰满,材料表现出良好的塑性。

MICROSTRUCTURE AND MECHANICAL PROPERTIES OF Y2O3 MODIFIED-Al2O3 PARTICLE /6061Al COMPOSITES

The liquid encapsulated approach was used in rare-earth modification on the surface of α-Al2O3 micro powder in this paper. Then the aluminum matrix composite reinforced by the α-Al2O3 particles that had been modified by Y2O3 was fabricated using the squeeze-casting technique. And the microstructure and tensile properties of the composites were analysed and studied. The result showed that α-Al2O3 micro powders modified by Y2O3 were distributed uniformly in the aluminum liquid. The interfacial wettability was improved. The microstructure of the composites was more even.The TEM observation showed that the α-Al2O3 powders were encapsulated homogeneously. EDAX analysis indicated that the powder surfaces included high content of Y and Al elements. And the diffraction peak of Y2O3 was also found in the X-ray diffraction spectrum graph. The tensile testing indicated that the strengthening effect of the modified-Al2O3 on Al alloy was improved obviously and the tensile strength of composites was improved 29.8 %,the yield strength was increased 38.4 % and the elongation was ncreased 10.3 %.The SEM analysis of the fracture indicated that the dimples of the modified-Al2O3P/6061Al composites were more even and the material embodied good plastics.