户外高压隔离开关用银石墨自润滑复合镀层的制备及性能研究

发布时间：2018-05-29 09:06

  本文选题：高压隔离开关 + 银镀层　； 参考：《南昌航空大学》2015年硕士论文

【摘要】：户外高压隔离开关是电力系统中最重要的电气设备之一,其电接触部位常常由于过热而失效,每年都造成大量的经济损失。本文以户外高压隔离开关触头为应用背景,采用电沉积法制备了银镀层与银石墨自润滑复合镀层,使用显微观察、扫描电子显微镜(SEM)、场发射扫描电镜(FESEM)、X射线衍射(XRD)、能谱仪(EDS)、热重/差热分析(TG/DTA)、红外碳硫分析、中性盐雾试验、Tafel曲线、摩擦磨损试验、扫描磨损轮廓等测试手段与表征方法,对银镀层与复合镀层的形貌、成分、生长机制、结合力、耐蚀性、抗硫性、热稳定性、耐磨性及磨损机制等进行了研究。研究表明,由于石墨的尖端放电效应和电极表面扩散层的存在,银的生长受限,呈现出有择优取向的线性连结生长方式,使得复合镀层孔隙率比银镀层高。根据GB/T 5270-2005,纯银镀层与复合镀层断口不起皮、不脱落,结合力良好;根据GB/T 6461-2002,两种镀层表面均未出现腐蚀点与腐蚀坑,耐蚀性达到中性盐雾试验十级标准;根据QJ485-1988,两种镀层在Na2S溶液中浸泡半小时不变色,抗变色能力达到航空标准。纯银镀层在室温~120℃表面发生氧化形成Ag2O,120℃~664℃银镀层氧化膜持续分解;室温~48℃为复合镀层的气体脱附阶段,48℃复合镀层中的水分开始蒸发,130℃时蒸发完全,160℃~521℃为石墨层间化合物的分解阶段,521℃~740℃石墨的碳骨架开始氧化。磨损试验表明,260 g载荷下纯银镀层的摩擦系数为0.342,复合镀层摩擦系数为0.075。复合镀层在小于260 g载荷下以磨粒磨损为主;随着载荷从260 g逐渐增加至860 g,疲劳磨损剥层开始出现,并且疲劳磨损逐渐成为主要磨损机制,同时磨粒磨损减少,复合镀层的摩擦系数始终保持在0.1以下。随着沉积电流密度的增大,复合镀层中石墨含量增多,在1 M H2SO4溶液中的自腐蚀电流密度增大,耐磨性能先增强后减弱,0.3 A/dm2电流密度下镀层耐磨性最好。随着搅拌速度的增大,复合镀层中石墨的含量增大后减小,在1 M H2SO4溶液中的自腐蚀电流密度先增大后减小,耐磨性能减弱,420 r/min搅拌速度下的磨损率最低,为8.13×10-14 m-3/N·m。
[Abstract]:Outdoor high voltage isolating switch is one of the most important electrical equipments in power system. Its electrical contact part often fails because of overheating, which causes a lot of economic losses every year. In this paper, the silver coating and silver graphite self-lubricating composite coating were prepared by electrodeposition under the background of outdoor high-voltage isolating switch contacts. Scanning electron microscope (SEM), field emission scanning electron microscope (SEM), X-ray diffraction (XRD), energy dispersive spectrometer (EDS), thermogravimetric / differential thermal analysis (TGR), infrared carbon-sulfur analysis, neutral salt spray test, friction and wear test, scanning and wear profile, etc. The morphology, composition, growth mechanism, adhesion, corrosion resistance, sulfur resistance, thermal stability, wear resistance and wear mechanism of silver and composite coatings were studied. The results show that the growth of silver is limited due to the tip discharge effect of graphite and the existence of diffusion layer on the electrode surface. According to GB/T 5270-2005, the fracture surface of pure silver coating and composite coating is not peeled, does not fall off, and the adhesion is good, according to GB/T 6461-2002, there are no corrosion points and corrosion pits on the surface of the two coatings, and the corrosion resistance reaches the 10th grade standard of neutral salt spray test. According to QJ485-1988, the two coatings were immersed in Na2S solution for half an hour without discoloration, and the anti-discoloration ability reached the aviation standard. The oxidation of pure silver coating on the surface of silver deposit at room temperature of 120 鈩，

本文编号：1950305