硬质合金基体预处理工艺对CVD金刚石涂层附着性能的影响

Effects of WC-Co Substrate Surface Pretreatments on Adhesion Property of CVD Diamond Coatings

采用热丝CVD法通过不同基体处理工艺在YG8和YG6硬质合金基体上沉积了金刚石涂层,考察了基体表面预处理工艺对基体表面形貌、残留钴含量以及涂层结合力的影响。实验结果表明,一步法酸刻蚀的最佳作用时间为15min左右,无论采用一步法还是二步法,处理后的YG8硬质合金基体表面残留钴均已大幅降低至3%左右,而二步法处理后YG6基体表面钴含量仅为0.66%。通过压痕实验对比分析得出,一步法酸处理15min后的硬质合金基体上沉积的金刚石涂层压痕较小,其最大压痕尺寸为145μm,两步法处理硬质合金基体金刚石涂层压痕面积最小,表现出良好的附着性能。

Diamond coatings were deposited on the cemented carbide substrate of WC -8% Co and WC -6% Co with different surface pretreatments by Hot Filament Chemical Vapor Deposition, the effect of surface pretreatment methods and acid treat time on the surface morphology and cobalt content of the cemented carbide substrate was investigated. It was found that the best acid treat time was about 15min. in one step acid pretreatment, and the surface cobalt content of WC - 8% Co decreased greatly and almost decreased to about 3% whatever adopting one - step or two - step etching pretreatments, and the surface cobalt content of WC - 6% Co pretreated by two - step method was 0.66%. The indentation experiments results showed that the CVD diamond coatings after etching for 15minutes by one - step method possessed the smallest indentation size of 145μm, the diamond coating deposited with two -step etching method had the smallest indentation area and possessed better adhesion property.