水润滑对铝基材料摩擦学行为的影响研究

Effect of Water Lubrication on the Tribological Behavior of Aluminum Based Materials

采用电化学方法,制备了4种铝基表面(未抛光铝(UNP-Al)、抛光铝(P-Al)、未抛光多孔阳极氧化铝(UNP-PAA)和抛光多孔阳极氧化铝(P-PAA))。利用原子力显微镜观察了不同铝基表面的表面形貌,采用接触角测定仪考察了铝基表面的润湿性,并通过UMT-2型球-盘式往复摩擦磨损试验机系统研究了表面处理和水润滑对不同铝基表面的摩擦学行为的影响。结果表明:在边界润滑条件下,所制备4种样品的摩擦系数向稳态转变的时间被推迟,且其摩擦系数在最开始阶段最小,但混合摩擦情况下的摩擦系数低于干摩擦条件。混合摩擦情况下,PAA的摩擦系数高于Al,但是PAA的表面磨痕相对较浅较细。这种现象表明PAA的表面织构可以存储润滑剂(水)和界面的磨屑,从而产生较好的抗磨损效果。

Four kinds of aluminum-based surfaces （unpolished aluminium （UNP-A1）, potished aluminium （P-A1）, unpolished porous anodic aluminum oxide （UNP-PAA） and polished porous anodic alumina （P- PAA）） were prepared using electrochemical method. The surface morphologies of the as-prepared samples were observed on an atomic force microscope. The wettabilities of the surfaces of the aluminum-based sam- ples were examined by a contact angle tester. The effects of surface treatment and water lubrication on the tribological behavior of the so-obtained samples were systematically studied on a UMT-2MT tribometer. The results revealed that the transition time of friction coefficients of the four as-prepared samples to steady state is delayed under boundary lubrication and the friction coefficients were lowest at the first stage. Besides, the friction coefficients of the four as-prepared samples were lower under the mixed friction than that under the dry friction. Moreover, the friction coefficient of PAA films are higher than that of A1 under the mixed friction conditions. However, the wear scars of PAA films are relatively shallow and com- paratively fine. The observed phenomena implied that the specific textures on the surfaces of PAA films can store lubricant （water） and trap wear debris from the interface, resulting in better anti-wear proper-ties.