化学镀Cu/Al_2O_3纳米颗粒增强铝基复合材料的显微组织及性能

Microstructure and Properties of Electroless Plating Cu/Al_2O_3 Nano Particles Reinforced Aluminum Matrix Composites

用化学镀方法成功制备了Cu包覆纳米α-Al2O3粒子,研究了Cu/Al2O3作为增强颗粒对铝基复合材料的显微组织和性能的影响。在超声波辅助下,将Cu/Al2O3掺杂到Al-7Si-0.3Mg合金中制得铝基复合材料。显微组织分析表明,掺杂Cu/Al2O3会影响复合材料的微观结构,晶粒的尺寸变小,形状从树枝状逐步转变为等轴状,同时共晶硅也由原来的针状变为颗粒状;力学性能测试表明,掺杂Cu/Al2O3的复合材料的屈服强度、抗拉强度和伸长率相对于未掺杂以及1.0%Al2O3掺杂时,都有显著提高。结果表明,Cu/Al2O3作为增强颗粒能改善与铝基体的润湿性,促进异质形核,改变晶粒的生长方式和材料的微观结构,从而改善复合材料的综合性能。

Cu-coated α-A1203 powders were successfully prepared by electroless plating process in this wore The effects of the addition of Cu-coated Al2O3 powders on the microstructure and properties of aluminum matrix composites were studied. The Cu-coated Al2O3 powders were added into the aluminum molten Al-7Si-0.3Mg with the ultrasonic vibration assisted. The analysis of the microstructure and properties showed that the sizes of grains in the alloy with Cu/Al2O3-doped were decreased obviously and the dendrite changed to equiaxed grain. Comparing with 1.0wt.% Al2O3-doped, the yield, tensile strength and elongation of Cu/A1203-doped alloy improved obviously. The results show that the wettability of Al matrix was improved because of strength particle Cu/Al2O3 adding. This could induce the heterogeneous nucleation, change the growth behavior of the grains and the microstructure of materials. As a result, the combination properties of the composites were improved.