化学脱钴对硬质合金沉积金刚石薄膜的影响  

Effects of chemical surface pretreatments on diamond coatings on cemented tungsten carbide substrate

作　　者：魏秋平[1] 余志明[1] 马莉[2] 杨莉[1] 刘王平[3] 肖和[3] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]中南大学粉末冶金国家重点实验室,长沙410083 [3]株洲硬质合金集团,株洲412000

出　　处：《中国有色金属学报》2008年第6期1070-1081,共12页The Chinese Journal of Nonferrous Metals

摘　　要：采用HFCVD系统,以CH4和H2为反应气体,分别在YG3、YG6、YG10、YG13硬质合金上沉积了金刚石薄膜,研究了化学脱钴处理对不同钴含量硬质合金沉积金刚石薄膜的影响。通过对105个样品的实验结果进行统计分析发现,YG3所得金刚石薄膜样品具有足够结合强度的比例为89%;而YG6、YG10和YG13所得样品的相应值分别为24%、7%和0%。相反,YG3、YG6、YG10和YG13所得金刚石薄膜严重破坏的比例分别为0%、64%、72%和79%。研究表明,化学腐蚀脱钴处理能够解决金刚石涂层形核率低的问题,但难以解决高钴硬质合金的附着性差的问题。Diamond films were deposited on cemented tungsten carbide substrates of various cobalt content （3%, 6%, 10% and 12% Co） by hot filament chemical vapour deposition （HFCVD） to assess the role of cobalt on the quality and adhesion （reliability） of diamond coatings. The samples were characterized by X-ray diffractometry （XRD）, scanning electron microscope （SEM） in combination with energy dispersive spectrometer （EDS）. Prior to deposition, the substrates were submitted to surface roughening by Murakami＇s etching and to surface binder removal by acid liquor. The adhesion was evaluated by Rockwell indentation tests （60 kg） conducted with a Brale indenter and compared with the adhesion of diamond films grown onto WC-3% Co, WC-6% Co, WC-10% Co, and WC-13% Co, which were submitted to similar etching pretreatments and identical deposition conditions. According to the statistic table of adhesion distribution of 105 samples, YG3 substrate which has enough adhesion is 89%, and that of YG6, YG10 and YG13 substrate is 24%, 7% and 0%, respectively. However, the rate-of-failure of them is 0%, 64%, 72% and 79%, respectively. The results show that diamond films on YG3 substrates exhibit good adhesion levels, compared with those obtained for HFCVD diamond on YG6, YG10 and YG13 with similar microstructure.

关 键 词：金刚石薄膜 硬质合金 预处理 附着力 

分 类 号：TB43[一般工业技术]