超细晶Al5083合金和碳化硼增强Al5083基复合材料的室温和高温干滑动摩擦磨损行为

讨论机械球磨Al5083合金和Al5083?5wt.%B4C复合材料在室温和200°C下的摩擦行为和磨损机制。结果表明,由于常温下的氧化磨损,形成可保护试样表面的机械混合层。在室温和80 N载荷下,Al5083和Al5083?5wt.%B4C球磨样品有磨损迹象,但体积磨损量有限,磨损率分别为5.8×10?7和4.4×10?7mm3/(m·N)。在200°C和80 N载荷下,球磨Al5083样品磨损严重,磨损率达10.8×10?7 mm3/(m·N);Al5083?5wt.%B4C样品的磨损较轻,局部出现三体磨损,磨损率为5.3×10?7 mm3/(m·N)。位错钉扎和Hall?Petch理论等强化机制、高硬度和载荷传递效应是决定Al5083?5wt.%B4C复合材料磨损行为的关键因素。另一方面,球磨Al5083样品在200°C下磨损率较高可能与其局部晶粒长大和硬度下降有关。

Wear behavior and dry sliding tribological properties of ultra-fine grained Al5083 alloy and boron carbide-reinforced Al5083-based composite at room and elevated temperatures

Tribological behavior and wear mechanisms of mechanically milled Al5083 alloy and Al5083?5wt.%B4C composite at room temperature and 200°C were discussed.Results revealed that due to the oxidative wear at room temperature,a mechanically mixed layer(MML)was formed to protect the surface of the samples.Under 80 N of load at room temperature,the milled Al5083 and the Al5083?5wt.%B4C samples showed evidence of abrasion with limited volume loss.In this case,the wear rates were 5.8×10?7 and 4.4×10?7 mm3/(m·N),respectively.At 200°C and under 80 N of applied load,severe wear occurred in the milled Al5083 sample,and wear rate reached 10.8×10?7 mm3/(m·N)while the Al5083?5wt.%B4C sample showed mild wear with local 3-body abrasion and the wear rate reached 5.3×10?7 mm3/(m·N).Strengthening mechanisms such as dislocation pinning and the Hall?Petch theory,high hardness and the load transfer effect were crucial in determining the wear behavior of the Al5083?5wt.%B4C composite.On the other hand,the milled Al5083 sample represented a relatively high wear rate at 200°C,which seemed to be related to the local grain growth and a drop in its hardness.