发动机凸轮表面耐磨减摩薄膜的制备与表征

Preparation and characterization of films with high wear resistance and low friction coefficient on engine cam surface

采用闭环磁场非平衡磁控溅射技术在发动机80B钢凸轮表面分别制备了类金刚石(DLC)和CrTiAlN两种薄膜,并从显微硬度、微观形貌、摩擦因数和磨损量、接触疲劳寿命等方面对薄膜进行了表征。结果表明,薄膜硬度大于凸轮基体材料,薄膜均匀致密且膜基结合良好;镀膜凸轮在油润滑下的情况下减摩效果不明显,但耐磨性能大大提升,且其接触疲劳寿命均明显提高为凸轮基体的约2.5倍。DLC薄膜由于在摩擦的过程中形成了转移膜从而具有较小的磨损量和较高的抗接触疲劳寿命,在大马力发动机上具有更广阔的应用前景。

Diamond-like-carbon( DLC) film and CrTiAlN film were deposited respectively on the surface of 80 B steel engine cam by closed loop magnetic field unbalanced magnetron sputtering system,and the films were characterized by micro-hardness,micro-morphology,friction coefficient,wear loss and contact fatigue life tests. The results show that the hardness of films is higher than that of the cam base metal. The films are uniform and compact and well bonded with the substrate. The friction coefficients of the cams with surface film decreases a little under oil lubrication,but the wear resistance of the cams is greatly improved. Particularly,the contact fatigue life of the cam with films is obviously increased to about 2. 5 times of 80 B steel cam. Due to the transfer film formed in the friction process which has less wear loss and longer contact fatigue life,DLC film has a broad application prospect in heavy duty diesel engine.