α-SiC粉体化学镀铜及其对铁基复合材料性能的影响

Electroless Copper Plating on α-SiC Powder and Its Effect on Properties of α-SiC/Fe Composites

目的优化α-SiC颗粒化学镀铜工艺,改善α-SiC/Fe之间的界面浸润性和匹配性,提高α-SiC/Fe复合材料的力学性能。研究α-SiC粒径大小和镀液工艺对镀铜的影响以及镀铜对α-SiC/Fe复合材料力学性能的影响。方法在对α-SiC颗粒粗化、敏化和活化后,采用化学镀覆的方式对5、10、15、20μm四种不同粒径的α-SiC进行表面镀铜。采用SEM和XRD对镀层的表面形貌和物相进行表征,采用SEM对α-SiC/Fe复合材料的显微组织进行观察。结果 4种粒径的α-SiC表面都成功地镀上了铜,且α-SiC颗粒粒径越小,表面积越大,镀速越高。确定了化学镀液的最佳工艺:温度65℃,溶液pH值9~11,SnCl_2加入量9 g/L,Pd Cl2加入量1.5 g/L。镀层形貌为凹凸不平的铜粒子集合体,物相为α-SiC、Cu和少量的Cu_2O。5、10、15、20μm的α-SiC颗粒镀铜提高了α-SiC/Fe复合材料的致密度、抗拉强度和延伸率,镀铜后致密度分别提高了0.62%、0.73%、0.95%、1.06%,抗拉强度分别提高了5.58%、10.97%、11.63%、13.02%,延伸率分别提高了6.35%、12.35%、10.19%、10.37%。结论α-SiC的粒径和镀液工艺显著地影响着镀速和镀层形貌。镀铜能够有效地改善α-SiC/Fe复合材料的界面缺陷,提高其力学性能。

The work aims to optimize electroless copper plating process of α-SiC particles, enhance interfacial wettability and compatibility between α-SiC and Fe, and improve mechanical properties of α-SiC/Fe composites. Besides, it aims to study effects of α-SiC particle size and plating process on copper plating, and effects of copper plating on mechanical properties of α-SiC/Fe composites. After roughening, sensitization and activation of α-SiC particles, α-SiCs with different particle size of 5, 10, 15 and 20 μm were copper-plated by electroless plating. Surface morphology and phase of the coatings were characterized with SEM and XRD. Microstructures of α-SiC/Fe composites were observed with SEM. As a result, the four kinds of α-SiC surfaces were successfully copper-plated. The smaller the particle size was, the larger the surface area and the higher the plating rate were. The optimum process of electroless plating solution was determined as follows： temperature of 65 ℃, solution pH of 9~11, SnCl2 amount of 9 g/L, and PdCl2 amount of 1.5 g/L. Morphology of the coatings was aggregate of rugged copper particles, phases were α-SiC, Cu and a small amount of Cu2O. Electroless plating of α-SiCs with different particle size of 5, 10, 15 and 20 μm improved density, tensile strength and elongation of α-SiC/Fe composites. The density increased by 0.62%, 0.73%, 0.95% and 1.06%, respectively; tensile strength by 5.58%, 10.97%, 11.63% and 13.02%, respectively; and elongation by 6.35%, 12.35%, 10.19% and 10.37%, respectively. Particle size of α-SiC and plating solution process significantly affect plating speed and coating morphology. Copper plating can effectively improve interface defects of α-SiC/Fe composites and enhance mechanical properties.