退火处理对Ni-Cr纳米电刷镀层的结构、硬度和摩擦学性能的影响

The Influence of Annealing Treatment on the Structure,Hardness and Tribological Properties of Ni-Cr Brush Plated Nanocoatings

采用电刷镀技术,以Ni-Cr镀液制备了Ni-Cr纳米电刷镀层并对其进行了退火处理;采用X射线衍射仪,扫描电子显微镜,能量色散谱仪分析了不同温度下退火处理的Ni-Cr纳米镀层的形貌以及结构;分别利用MH-5-VM型显微硬度计和CSM摩擦试验机测定了刷镀层的显微硬度和摩擦磨损性能.研究结果表明：镀层晶粒的大小均为纳米级,随温度变化不大,介于10-20 nm之间,在500℃以下,Cr以固溶体形式存在于Ni的晶格中,500℃以上Cr从Ni的晶格中析出;镀层的耐磨性随退火温度的变化与镀层的硬度随温度的变化大致相同：Ni-Cr刷镀层在400℃退火处理时,硬度最大,磨损率最小.

Electric brush plating was employed to prepare Ni-Cr nanocoatings from Ni-Cr plating solution and an annealing treatment was carried out. X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy were used to analyze the surface morphology and phase structure of the coatings after annealing treatment at different temperatures. MH-5-VM type microhardness tester and CSM friction tester were used to measure the hardness and wear properties of the coating. The grain size of the coating was ranging from 10 nm to 20 nm for all annealing temperature..At annealing temperatures lower than 500 °C, Ni-Cr solid solution was revealed. At annealing temperatures higher than500 °C, Cr precipitate was observed. The variation of the wear resistance of the coating at elevated followed almost same trend as that of the microhardness. The coating which was annealed at 400 °C showed the highest hardness and the best wear resistance.