铁基金属玻璃涂层在无铅钎料中的耐腐蚀性及机理

Corrosion Resistance and Mechanisms of Fe-Based Metallic Glass Coating in Molten Lead-Free Solder

选用Fe基非晶合金粉末(含有Cr、Mo、Ni、P、B、Si),采用等离子喷涂方法在Q235基体上制备了金属玻璃涂层.在自行设计的腐蚀实验装置中将Q235钢、1Cr18Ni9Ti不锈钢和覆有Fe基金属玻璃涂层的Q235钢浸入450,℃的高温液态无铅钎料Sn-3.5,Ag-0.5,Cu中进行腐蚀,利用扫描电子显微镜微观分析了腐蚀后的微观形貌及腐蚀产物.研究结果表明:相同实验条件下,Q235钢和1Cr18Ni9Ti不锈钢表面均腐蚀严重,断面微观组织分为钎料层、腐蚀层和基体层.其中Q235钢的腐蚀剧烈,腐蚀层成分为FeSn2;1Cr18Ni9Ti不锈钢腐蚀较严重,腐蚀层成分为(Fe,Cr)Sn2.Q235基体表面的Fe基金属玻璃涂层腐蚀前后断面微观形貌变化不大,没有出现明显的腐蚀分层,表现出了非常好的耐高温无铅钎料腐蚀的能力.

A kind of Fe-based alloy powder（containing Cr,Mo,Ni,P,B,Si,）with high glass formation ability was deposited on Q235 steel by plasma spraying（APS）technique. The corrosion resistance of the Q235 steel,1Cr18Ni9Ti stainless steel and Q235 steel with Fe-based metallic glass coating was evaluated by high temperature（450,℃）molten lead-free solder in a self-designed corrosion experimental set-up. The cross-sectional microstructure and corrosion products of the samples were analyzed by scanning electron microscope（SEM）with energy disperse spectroscopy（EDS）. The results show that both of the surfaces of Q235 steel and 1Cr18Ni9Ti stainless steel are corroded significantly in the same experimental conditions. The cross-sections are divided into solder layer,corrosion layer and substrate layer. The composition of the corrosion layer of Q235 steel is FeSn2. However,the corrosion mechanism of 1Cr18Ni9Ti stainless steel is uniform corrosion and the composition of the corrosion layer is（Fe,Cr）Sn2. The cross-sectional microstructures of Fe-based metallic glass coating on Q235 surface have little change.Therefore,it is concluded that the Fe-based metallic glass coating has excellent high temperature lead-free solder corrosion resistant capacity.