共查询到19条相似文献,搜索用时 46 毫秒
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采用不同浓度的盐酸、FeCl3溶液为腐蚀介质,研究了RE-Ni-W-P-SiC-PTFE复合电镀层于镀态下及经不同温度热处理后的腐蚀速率与阳极极化曲线,并与RE-Ni-W-P-SiC复合电镀层的阳极极化曲线进行了比较.结果显示,RE-Ni-W-P-PT-FE-SiC复合镀层于镀态下或经200、300、400、500℃热处理后,随着盐酸浓度的升高,其腐蚀速率先升高,当盐酸质量分数达到15%时,腐蚀速率达到极大值,进一步提高盐酸浓度,复合镀层的腐蚀速率有所下降;RE-Ni-W-P-PTFE-SiC复合镀层在镀态或200、300、400℃热处理后,随着氯化铁浓度的增加,腐蚀速率先增加,而后有下降的趋势,最后又有所上升,而在500℃热处理温度下,镀层腐蚀速率随FeCl3浓度的增加而一直缓慢增加.阳极极化曲线表明:200℃或500℃热处理后复合镀层具有较好的耐蚀性. 相似文献
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S. T. Aruna V. K. William Grips V. Ezhil Selvi K. S. Rajam 《Journal of Applied Electrochemistry》2007,37(9):991-1000
Incorporation of ceria particles into the Ni matrix was found to improve the corrosion resistance of pure Ni coatings. With
the aim of further improving the corrosion resistance of Ni-ceria, yttria was doped with ceria and used as distributed phase.
About 8-mol% yttria doped ceria (8YDC) particles synthesized by a solution combustion process were dispersed in a nickel sulfamate
bath and electrodeposition was carried out to prepare Ni–8YDC composite coatings at various current densities. The microhardness
of the composite coatings was determined. Optical microscopy confirmed the incorporation of 8YDC particles into the Ni matrix.
Potentiodynamic polarization and electrochemical impedance spectroscopy were used to characterize the corrosion behavior of
the Ni–8YDC coatings. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Analysis (EDAX) were used to characterize
the corroded samples. The results were compared with those for Ni and Ni–CeO2 coatings. The wear behavior of Ni–8YDC was studied. Wear tracks were characterized by MicroRaman Spectroscopy. 相似文献
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研究了镀液组成及工艺参数对电沉积RE Ni W B复合镀层硬度和沉积速度的影响,以及不同热处理温度下复合镀层硬度、磨损率及抗氧化性的变化规律。结果表明:在最佳工艺条件下,复合镀层的沉积速率为5 13μm/h,硬度为667HV。采用X射线能谱仪测试镀层成分表明,RE Ni W B复合镀层中各成分的质量分数分别为wW=0 49%,wB=1 17%,wCe=1 99%。热处理温度对复合镀层硬度、磨损率及抗氧化性有较大的影响,热处理温度提高,复合镀层的硬度先增加后降低,磨损率先降低后增加;当热处理温度为400℃时,硬度和磨损率分别达到最大值和最小值,即1087HV和0 64mg/(cm2·h);复合镀层的氧化增重随热处理温度的增加而增加,当热处理温度低于400℃时,镀层的氧化增重较小,热处理温度高于600℃,复合镀层的氧化增重大幅度增加。 相似文献
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Composite electroplating is a method allowing to co-deposit fine particles of metallic or non metallic compounds into the plated layers in order to improve the surface properties. The aim of the present work was to compare the performance of pure nickel and Ni-SiC nano-structured composite coatings as far as corrosion, wear and abrasion resistance were concerned. The characteristics of the coatings were assessed by scanning electron microscopy, micro hardness test, Taber Abrader test, electrochemical impedance spectroscopy and wear corrosion measurements. Additionally accelerated salt spray tests were performed. The results obtained in this study indicate that the co-deposition of nickel and SiC nano-particles leads to uniform deposits possessing better abrasion, wear and corrosion properties. 相似文献
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M.P. Quiroga Argañaraz S.B. Ribotta M.E. Folquer L.M. Gassa G. Benítez M.E. Vela R.C. Salvarezza 《Electrochimica acta》2011,(17):5898
Hard, ductile and adherent nanostructured Ni–W coatings were electrodeposited on carbon steel from electrolyte solutions containing sodium tungstate, nickel sulfate and sodium citrate, using different current pulse programs. Current pulse frequency was the dominant factor to define chemical composition, grain size, thickness and hardness. According to the electrodeposition conditions the deposited coatings showed 15–30 at% W, the grain size ranged from 65 to 140 nm, and the hardness varied from 650 to 850 Hv. Tungsten carbide also present in the coating contributed to its hardness. The corrosion resistance of the Ni–W coated steel was tested by potentiodynamic polarization in a neutral medium containing sulphate ions. The Ni–W coating protected the carbon steel from localized corrosion induced by sulphate anions. 相似文献
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High corrosion resistance of electroless composite plating coatings on AZ91D magnesium alloys 总被引:1,自引:0,他引:1
Y.W. Song 《Electrochimica acta》2008,53(5):2135-2143
The process of electroless plating Ni-P on AZ91D magnesium alloys was improved. The Ni-P-ZrO2 composite coatings and multilayer coatings were investigated based on the new electroless plating process. The coatings surface and cross-section morphologies were observed with scanning electron microscopy (SEM). The chemical compositions were analyzed by EDXS. The corrosion behaviors were evaluated by immersion, salt spray and electrochemical tests. The experimental results indicated that the Ni-P-ZrO2 composite coatings suffered attack in NaCl solution but displayed passivation characteristics in NaOH and Na2SO4 solutions. The corrosion resistance of Ni-P-ZrO2 coatings was superior to Ni-P coatings due to the effect of ZrO2 nano-particle. The multilayer coatings consisting of Ni-P-ZrO2/electroplating nickel/Ni-P (from substrate to surface) can protect magnesium alloys from corroding more than 1000 h for the salt spray test. 相似文献
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电沉积制备Pb-WC-ZrO2复合镀层的工艺及性能研究 总被引:4,自引:1,他引:4
通过在氟硼酸铅体系中加入适量的固体颗粒,制得Pb-WC—ZrO2复合镀层。主要研究了电沉积工艺条件(搅拌速度、电流密度及电沉积时间)对Pb-WC—ZrO2复合镀层成分、表面形貌和结合力的影响,从而得出最佳固体微粒加入量及工艺条件为:20~30g/L的ZrO2,20~30g/L的WC,搅拌强度500~600r/min,电流密度2~3A/dm^2,时间2h。在ZnS04-H2S04体系中进行的阳极极化曲线测定表明,此复合镀层适于作惰性阳极材料;电子探针成分分析表明,复合镀层中主要成分是Pb和O还舍有一定量的Zr和W元素,说明Zn和WC都沉积到镀层中;X-射线衍射分析表明,镀层中Pb的衍射峰最强,其次为WC的衍射峰,在衍射图中也存在ZrO2的衍射峰但比较微弱。 相似文献