层状Cr_2AlC纳米晶的合成及其摩擦学行为

Synthesis and Tribological Behavior of Nano-Cr_2AlC Powder

通过液相磁力搅拌混合原料粉末2Cr/1.2Al/1C,在1400℃无压烧结合成了Cr2AlC。X射线衍射结果表明,Cr2AlC具有良好的结晶性,扫描电镜照片显示合成的Cr2AlC为层状结构,厚度大约在50~100 nm。将其以不同质量分数分散到基础油100SN中,利用摩擦磨损试验机初步研究了滑行速度,载荷等对其摩擦学性能的影响,结果表明,Cr2AlC添加量较低时,分散性较好,能显著降低基础油的摩擦系数和摩擦磨损,高载荷会加剧磨损,实验条件下,Cr2AlC添加量为0.6%和1%的润滑油在10N载荷时,摩擦过程中在表面形成具有减摩抗磨作用的润滑膜,表现出较好的摩擦学性能。

The Cr2A1C powder was synthesized by pressure-less sintering of a mixture of chromium, aluminum and graphite（2Cr/1.2A1/1C）powders. The impacts of the sintering conditions, including the grain size of powers, sintering temperature and time, etc., on the microstmctures and properties of the Cr2A1C powder were studied. The Cr2A1C powder was characterized with X-ray diffraction, and scanning electron microscopy. Sintered at 1400℃, the lamella-shaped Cr2A1C crystal grains were found to be 50 - 100 nm in thickness. Its tribological property of the Cr2AIC as an additive in 100SN base oil was evaluated. The results show that addition of an optimized amount of CraA1C powder significantly improves friction and wear-resistance. Possible mechanisms responsible for the improvement were also tentatively discussed.