旋转摩擦挤压法制备CNTs/5A06铝基复合材料的摩擦磨损行为

Friction and Wear Behavior of CNTs/5A06 Aluminum Matrix Composite Prepared by Rotational Friction Extrusion Method

添加体积分数3%碳纳米管(CNTs),应用旋转摩擦挤压(RFE)法制备了CNTs/5A06铝基复合材料,研究了其显微组织、显微硬度和耐磨性能,并与RFE加工前后5A06铝合金的进行了对比。结果表明:RFE加工后铝合金组织由RFE加工前的粗大长条状晶粒变为细小等轴晶,但显微硬度增幅不明显,复合材料的晶粒进一步细化,硬度明显增加;RFE加工对铝合金摩擦因数与磨损率的影响较小,复合材料的摩擦因数与磨损率则分别比RFE加工前铝合金的降低了17.6%,34.7%;复合材料磨损表面光滑完整,存在塑性变形和少量犁沟,磨损机制为表面塑性变形和轻微的磨粒磨损,RFE加工前后铝合金的磨损表面均存在较多凹坑和犁沟,磨损机制为黏着磨损和磨粒磨损。

5 A06 aluminum matrix composite reinforced with 3 vol%carbon nanotubes(CNTs)was fabricated by rotational friction extrusion(RFE)method.The microstructure,microhardness and wear resistance of the composite were investigated and compared with those of 5 A06 aluminum alloy before and after RFE processing.The results show that the microstructure of the aluminum alloy changed from coarse long-strip-like grains before RFE processing to fine equiaxed grains after RFE processing,but the increase range of the microhardness was small.The grains in the composite were further refined and the hardness increased obviously.The RFE processing had little influence on the friction factor and wear loss rate of the aluminum alloy.The friction factor and wear loss rate of the composite decreased by 17.6%and 34.7%that of the aluminum alloy before RFE processing,respectively.The worn surface of the composite was smooth and complete with plastic deformation and less ploughing;the wear mechanism was surface plastic deformation and slight abrasive wear.The worn surface of the aluminum alloy before and after RFE processing had relatively more grooves and ploughing;the wear mechanism was adhesion wear and abrasive wear.