纳米二氧化硅对锂基润滑脂摩擦学性能的影响

利用溶胶-凝胶法,以正硅酸乙酯为原料制备了纳米二氧化硅微粒,通过透射电子显微镜对其结构进行了表征,利用四球摩擦磨损试验机测定了添加不同含量纳米二氧化硅锂基润滑脂摩擦学性能,采用扫描电子显微镜观察磨损表面形貌。结果表明:制备的纳米二氧化硅是粒径为60 nm左右的球形微粒,具有很高的表面能和表面活性;纳米二氧化硅作为锂基润滑脂添加剂能够提高最大无卡咬负荷和烧结负荷,降低摩擦因数,添加量为2.0%(质量分数)时的润滑剂性能最好,相对应的钢球磨斑直径最小,摩擦因数最低。

Effect of Tribological Properties of Nano-SiO2 Particles as Additives in Lithium Grease

Nano-SiO2 particles were prepared by sol-gel method with the tetraethyl-orthosilicate in the presence of ammonia as a catalyst.The morphology and phase structure of nano-SiO2 particles were characterized using transmission electron microscope.The tribological properties of lithium grease lubricant which was appended different mass nano-SiO2 particles were investigated by the four-ball friction and wear tester.The worn surface of the steel balls was observed using scanning electron microscope.The results show that the nano-SiO2 particles are spherical-shaped with the size of about 60 nm,they have high surface energy and activity.The lubricant with nano-SiO2 particles can form the locked-in absorbing films in the frictional surface,which improve the maximum non-seizer load and weld point,and decrease friction coefficient.The lubricant with mass content of 2.0% nano-SiO2 additive shows the best lubricating behavior,which wear scar diameter and friction coefficient are minimum.