硬质合金微细刀具多种硬质涂层的研究

Study on Various Hard Coating of Carbide Micro Cutting Tools

不同的刀具涂层具有不同的特性,为了寻找一种综合性能适用于微细刀具表面涂覆的涂层,本文在微细刀具基体材料硬质合金表面涂覆了包括微米金刚石(MCD)、纳米金刚石(NCD)、微纳米金刚石(MNCD)、普通类金刚石(DLC),含氢类金刚石(DLC-H)、四面体非晶碳类金刚石(TaC)薄膜及其复合薄膜在内的16种硬质薄膜。采用扫描电镜、三维白光干涉仪、洛氏硬度计、自制动载荷冲击试验机和摩擦磨损实验机分别表征了薄膜的微观表面和截面形貌、表面粗糙度、静和动载膜基结合强度及干摩擦学性能。实验发现,TaC薄膜虽在静和动载荷作用下,其膜基结合强度逊于DLC和DLC-H薄膜,但其表面光洁度,摩擦学性能明显优于DLC和DLC-H薄膜,可作为优秀的表面涂层。同时,将TaC薄膜与MNCD薄膜相结合,所得的MNCD+TaC薄膜兼具了底层MCD耐磨,中间NCD吸收冲击载荷,表层TaC薄膜光洁的优点,在所有薄膜中具有最低的摩擦系数和磨损率。

Different tool coatings have different properties. In order to find a coating that can be applied to the coating of micro-tool surface, 16 kinds of hard films, including MCD, NCD, MNCD, DLC, DLC-H, TaC thin films and their composite film, were coated on the surface of carbide alloy which is the substrate of micro cutting tool. The microscopic surface and cross-sectional morphology, surface roughness, static and dynamic film-based bonding strength and dry tribological properties of thin films were characterized by SEM, 3D white light interferometer, Rockwell hardness tester, selfmade dynamic load impact tester and friction and wear tester respectively. The experimental results show that although the bonding strength of TaC films is lower than that of DLC and DLC-H films under static and dynamic loading, the surface finish and tribological properties of TaC films are obviously better than that of DLC and DLC-H films. So the TaC film can be used as a good surface coating. Meanwhile, by combining TaC film with MNCD film, the obtained MNCD ＋ TaC film has the advantages of wear resistance of the bottom MCD, impact absorption of the middle NCD, smoothness of the surface TaC film, and the lowest friction coefficient and wear rate in all the films.