镀Ni金刚石与铜基结合剂间把持力的提高方法和机理分析

Method and mechanism analysis of improving the holding force between Ni-coated diamond and Cu-matrix bonding

为了提高金刚石与金属结合剂间的把持力,将镀Ni金刚石在1050℃下处理1 h,然后用浓硝酸清洗金刚石表面,最后采用真空热压烧结制备铜基结合剂金刚石样条。用扫描电子显微镜观察高温处理前后金刚石镀层表面形貌,通过铜基结合剂样条的抗弯强度来评价金刚石与铜基结合剂间的结合力。用X射线衍射仪分析高温处理后镀层与金刚石间的物相。结果表明:镀Ni金刚石经1050℃处理1h后,镀层基本上保持完整,金刚石表面变粗糙;铜基结合剂金刚石样条的抗弯强度从未镀金刚石的759 MPa增加到镀Ni金刚石的791 MPa,再增加到高温处理镀Ni金刚石的833 MPa,说明金刚石与铜基结合剂间把持力得到有效提高。

To improve the holding force between the diamond and metal matrix bonding, the Ni-coated diamond was treated at 1050 ℃ for 1 h, then the diamond surface was cleaned by the concentrated nitric acid, finally, the Cu-matrix bonding diamond segments were prepared by vacuum hot-pressing sintering. The surface morphologies of diamond coatings before and after high temperature treatment were observed by scanning electron microscope. The flexural strength of Cu-matrix bonding diamond segments was measured to evaluate the holding force between diamond and Cu-matrix bonding. The phases between the coating and diamond after high temperature treatment were analyzed by X-ray diffraction. The results show that, the Ni coating treated at 1050 ℃ for 1 h mainly maintains integral and the diamond surface was roughened. The flexural strength of Cu-matrix bonding diamond segments increases from 759 MPa for the uncoated diamond to 791 MPa for the Ni-coated diamond, and then to 833 MPa for the Ni-coated diamond after high temperature treatment, showing the effective improvement of the holding force between Ni-coated diamond and Cu-matrix bonding.