材料期刊网

目的：研究利用电刷镀技术对铸铁表面进行刷镀修复。方法在铸铁表面电刷镀Ni和Ni-P两种镀层,观察镀层的表面形貌,分析镀层的物相组成,检测镀层结合力、耐磨性及耐蚀性等性能。结果在铸铁表面获得了结合紧密且晶粒大小均匀、致密的Ni-P刷镀层。 Ni刷镀层较Ni-P刷镀层晶粒细小,具有较多孔洞,结构疏松。在相同刷镀时间下,Ni-P刷镀层厚度约为0.1 mm,是Ni刷镀层的2倍；与基体的结合力为85 N,而Ni刷镀层结合力为48 N。 Ni-P和Ni刷镀层均主要由Ni,Fe10.8 Ni和FeNi3组成,并含有少量的铜。 Ni-P刷镀层的磨损质量和磨损体积最小,具有更好的耐磨性能；Ni刷镀层由于较疏松,出现了较严重的粘着磨损和擦伤特征。 Ni-P刷镀层的自腐蚀电位最高,腐蚀电流密度最小,具有较好的耐腐蚀性能。结论通过电刷镀可对铸铁表面进行修复,提高其耐蚀和耐磨性能,其中Ni-P刷镀层的修复效果较好。

ABSTRACT:Objective To repair the cast iron surface by electron-brush plating. Methods The Ni-P and Ni-based coatings were prepared on cast iron by electron-brush plating. The microstructure and phase composition of the coatings were observed, and prop-erties of the coatings such as coating adhesion, wear behavior and corrosion resistance were tested. Results Compact and dense Ni-P coating with even grains was obtained on the surface of the cast iron. Compared to the Ni-P coating, the Ni-based coating was loose and porous, with finer grains. The thickness of the Ni-P coating was about 0. 1 mm, which was 2 times as thick as that of the Ni-based coating after the same plating time. The adhesions of Ni-based and Ni-P coatings were 48 N and 85 N, respectively. Both the Ni-based and Ni-P coatings mainly consisted of Ni, Fe10. 8 Ni and FeNi3 phases, and contained a small amount of Cu. The wear resistance of Ni-P coating was the best with the lowest wear quantity and volume loss. The corrosion resistance of the Ni-P electro-brush coating was the best, with the highest Ecorr and lowest self-corrosion current density. Conclusion Electron-brush plating
could be used to repair the surface of cast iron by increasing its corrosion resistance and wear resistance, and the Ni-P electro-brush coating showed better properties.