磁控溅射银镀层和电镀银镀层硬度及结合性对比研究

Comparison of Hardness and Adhesion Strength between Magnetron Sputtered and Electroplated Silver Coatings

采用电镀与中频-直流磁控溅射技术分别在Inconel 718镍基高温合金基体表面制备银镀层。使用维氏显微硬度计和微纳米划痕仪分别测量两种镀层在室温下、工况使用温度退火后、极限温度退火后的硬度与附着力;借助SEM、EDS观察测试镀层的微观形貌以及元素构成在不同保温处理后的变化。结果表明,在室温25℃下磁控溅射银镀层的显微硬度是139.7 HV,其硬度与电镀银镀层相比增强45.5%;附着力为40 N,是电镀法制得的3倍。保温处理后由于中频-直流磁控溅射法制得的银镀层的单个晶粒平均尺寸更小且分布更均匀,镀层与基体间界面的氧化被更好地抑制。相比传统电镀银镀层,400℃下磁控溅射银镀层硬度与结合性相比电镀银镀层有显著提高;但在650℃下优势较小,24 h后两种镀层都出现脱落。

Silver coatings were prepared by medium frequency-direct current(MF-DC)magnetron sputtering and traditional electroplating on Inconel 718.The hardness and adhesion strength of the two coatings under different temperature conditions were measured by Vickers microhardness tester and micro-nano scratcher.The microstructures and elemental composition of the coatings were analyzed using SEM and EDS.Results show that the microhardness of the magnetron sputtered silver coating at 25℃is 139.7 HV,increasing by 45.5%compared with the electroplated silver coating,and the adhesion strength is 40 N which is 2 times higher than electroplated silver coating.Due to the smaller average size of single crystal grains and more uniform distribution in the silver coating deposited by MFDC magnetron sputtering,the oxidation of the interface between the coating and the substrate is suppressed.Comparing to the electroplated silver coating,its hardness and adhesion strength at 400℃are significantly improved.But after 24 hours at 650℃,both coatings peel off.