掺硼金刚石/硬质合金膜基结合和摩擦磨损性能的研究

Adhesive and tribological properties of boron-doped diamond films on cemented carbide

金刚石刀具涂层在碳纤维复合材料等难加工材料高效加工方面有着广阔的应用前景。在热丝化学气相沉积系统通过气体掺硼,在硬质合金表面制备了掺硼金刚石涂层。通过SEM、Raman以及压痕测试对涂层的表面形貌、成分和膜基结合性能进行了测试和分析;对涂层进行了摩擦磨损实验,研究了涂层不同环境温度下的摩擦系数及磨损率。结果表明,适量的硼掺杂可以细化金刚石晶粒,提高膜基结合力,降低摩擦系数并提高耐磨性,掺硼金刚石磨损率随温度的升高而增大,本文合适的掺硼浓度为3×10-3。

Diamond coated cutting tools have wide application potentials in the high-performance machining of difficult-to-machine material such as carbon fiber composites.In this paper,boron-doped diamond films were prepared on WC-Co cemented carbide inserts using hot filament chemical vapor deposition(HFCVD)technique in the mixture of B2H6,H2 and CH4.The surface morphology,quality and adhesive strength of BDD films were characterized by the scanning electron microscopy,Raman spectra and Rockwell-C indentation,respectively.The tribotests were carried out to study the coating coefficient of friction and the wear rate under different temperatures.The proper boron level will refine the diamond grain size.The adhesion between coating and substrate can improved at the B/C ratio of 3×10-3.Furthermore,the friction coefficient can be reduced and the wear resistance can be improved at this boron concentration.The wear rate increases with increasing temperature under an appropriate boron doping level.