人工模拟海洋大气环境下Sn-0.7Cu无铅焊料的点蚀行为及微量Ga的影响  

PITTING CORROSION BEHAVIOR OF Sn-0.7Cu LEADFREE ALLOY IN SIMULATED MARINE ATMOSPHERIC ENVIROMENT AND THE EFFECT OF TRACE Ga

作　　者：颜忠[1] 冼爱平[1] 

机构地区：[1]中国科学院金属研究所沈阳材料科学国家(联合)实验室,沈阳110016

出　　处：《金属学报》2011年第10期1327-1334,共8页Acta Metallurgica Sinica

基　　金：中国科学院金属研究所研究生创新基金项目119300290资助;广东省-中国科学院全面战略合作项目2009B091300039~~

摘　　要：通过人工海水的盐雾干-湿实验模拟海洋大气环境,研究了Sn-0.7Cu和Sn-0.7Cu-0.01Ga合金的腐蚀行为.采用SEM和XPS分析了合金表面腐蚀形貌及腐蚀产物成分,采用XRD分析了腐蚀产物的结构.结果表明:Sn-0.7Cu合金腐蚀初期发生明显的点蚀,点蚀易于在富Cu区萌生,且以触须状向外扩展;腐蚀后期腐蚀产物分层,龟裂且易于剥落,此时腐蚀产物不具有保护性.XRD分析表明.腐蚀产物主要为非晶态Sn的氧化物,同时有少量的SnCl_2·2H_2O;微量元素Ga能显著提高Sn-0.7Cu合金的抗盐雾腐蚀性能.XPS分析表明,微量元素Ga在表面存在明显的富集行为,并形成一种致密的保护性氧化膜,它是提高Sn-0.7Cu合金抗盐雾腐蚀性能的主要原因.The corrosion behaviors of Sn 0.7Cu and Sn 0.7Cu 0.01Ga alloys have been investi- gated by salt spray dry wet test with artificial seawater to simulate marine atmospheric environment. The surface corrosion products were analyzed by SEM, XPS and XRD. The results show that, at the early stage of corrosion process, the pits easily form at the Cu enrichment area on the surface of Sn- 0.7Cu alloy, then the pits propagate by the way of the tentacles. Latter the corrosion product cracks, laminates and falls off, so that it does not give resistance to the future corrosion. XRD result shows that the corrosion products are mainly composed of amorphous oxide of Sn and a few SnC12.2H20. The addition of trace Ga in the Sn-0.7Cu alloy can significantly improve the corrosion resistance of the alloy in the salt spray test. XPS result shows that trace Ga segregated highly on surface and existed a protective oxide film that can improve the corrosion resistance of the Sn 0.7Cu alloy.

关 键 词：SN-0.7CU 点蚀 盐雾腐蚀 无铅焊料 

分 类 号：TG172.3[金属学及工艺—金属表面处理]