【摘要】 目前,有关工艺参数对脉冲电沉积纳米晶镍钴合金结构及性能的影响研究还不系统。采用双脉冲电沉积技术于不同的糖精浓度和镀液温度下在SUS201不锈钢表面制备了纳米晶镍钴合金镀层。运用X射线衍射(XRD)、扫描电镜(SEM)等方法研究了合金镀层的相结构﹑择优晶面取向和表面形貌,并用Scherrer公式计算了镀层的晶粒尺寸;通过中性盐雾腐蚀试验和极化曲线测试了镀层的耐蚀性。结果表明:镍钴合金镀层是具有面心立方结构(fcc)的纳米晶,主要的晶面取向为(111)和(200);提高镀液中的糖精浓度,镀层的平均晶粒尺寸减小,耐蚀性增强;升高镀液温度,镀层耐蚀性先增强后减弱,镀液温度30℃时镀层的耐蚀性较强。更多还原

【Abstract】 A series of nanocrystalline Ni-Co alloy coatings were prepared on SUS201 stainless steel substrate by dual-pulse electroplating at different saccharin concentration and bath temperature. The phase structure( preferred orientation planes) and morphology of as-prepared Ni-Co alloy coatings were analyzed by means of X-ray diffraction and scanning electron microscopy; and the grain size of the alloy coatings was calculated by using Scherrer formula. Besides,the corrosion resistance of Ni-Co alloy coatings was evaluated based on neutral salt-spray corrosion test and electrochemical test(measurement of polarization curves). The results demonstrated that as-prepared Ni-Co alloy coatings consisted of nanocrystallites with face centered cubic structure,and the nanocrystallites were dominated by preferred orientations along(111) and(200) planes. In the meantime,the average grain size of the alloy coatings tended to decline with increasing saccharin concentration while their corrosion resistance tended to rise therewith. With the increase of bath temperature,the corrosion resistance of the alloy coatings tended to rise initially but decline later; and in particular,the Ni-Co alloy coating obtained at a bath temperature of 30 ℃ exhibited desired corrosion resistance.更多还原