T6态CNTs/Al-Zn-Mg-Cu复合材料的耐磨性能研究

Study on Wear Resistance of T6 Treated CNTs/Al-Zn-Mg-Cu Composite

采用熔融铸造法制备了12vol%CNTs(碳纳米管)/Al-Zn-Mg-Cu复合材料,再对该复合材料进行T6热处理。利用MG-200型摩擦磨损试验机研究了热处理前后CNTs/Al-Zn-Mg-Cu复合材料的干滑动摩擦磨损性能。试验结果表明:CNTs对Al-Zn-Mg-Cu合金有细晶强化作用,提高了合金的硬度,固溶处理消除了铸造复合材料中的第二相偏析,并且在时效处理之后MgZn2强化相的析出大幅度提升了材料的性能。在40 N的载荷和200 r/min转速时,T6态CNTs/Al-Zn-Mg-Cu复合材料的磨损率和摩擦系数分别为0.0489 g/mm和0.281,与铸造复合材料相比,材料的磨损率和摩擦系数分别降低64.79%和28.47%。这是由于热处理之后试样的强度和硬度增大,从而有效改善了材料的耐磨性能。未热处理的复合材料主要存在黏着磨损和磨粒磨损,而热处理之后复合材料的主要磨损机理为磨粒磨损。

The 12vol% CNTs/Al-Zn-Mg-Cu composite was prepared by the molten casting method, and then the composite was subjected to T6 heat treatment. The dry sliding friction and wear properties of the composite before and after heat treatment were studied by MG-200 friction and wear tester. The experimental results show that CNTs have a fine-grain strengthening effect on Al-Zn-Mg-Cu alloy, which improves the hardness of the alloy. The solution treatment eliminates the segregation of the second phase in the as-cast composite, and after aging treatment, the precipitation of MgZn2strengthened phase greatly improves the performance of the material. At a load of 40 N and a speed of 200 r/min, the wear rate and friction coefficient of the T6 treated CNTs/Al-Zn-Mg-Cu composite are 0.0489 g/mm and 0.281, respectively. Compared with the as-cast composite, the wear rate and friction coefficient of the material decrease by 64.79% and 28.47%, respectively. This is due to the increase of strength and hardness of the sample after heat treatment, which effectively improves the wear resistance of the material. Adherent wear and abrasive wear are the main wear mechanisms of the composite without heat treatment,while abrasive wear is the main wear mechanism of the composites after heat treatment.