含纳米介孔SiO_2锂基润滑脂摩擦学与流变学性能研究

Tribological and Rheological Properties of Lithium Lubricating Grease Containing Nano-Mesoporous Silica

利用具有不同形貌和孔道结构的纳米介孔Si O_2作为添加剂,制备了含纳米介孔Si O_2的锂基润滑脂,采用Anton-paar NHT3纳米压痕测试仪和Anton-paar MCR302旋转流变仪考察了纳米介孔Si O_2形貌、孔道结构以及质量分数对锂基润滑脂摩擦学性能和流变学性能的影响.结果表明:球状的纳米介孔Si O_2添加剂能更有效降低锂基润滑脂的摩擦系数,增强锂基润滑脂的骨架稳定性,改善锂基润滑脂触变性,提高润滑脂的抗剪切能力以及热稳定性能.在中低剪切速率下对流变试验数据进行拟合,提出了基于纳米介孔Si O_2添加剂温度和质量分数参数的润滑脂改进型流变模型.

Lithium lubricating grease containing nano-mesoporous SiO_2 was prepared by using SiO_2 with different morphologies and pore structures as additive. The effects of morphology,pore structure and mass concentration of nanomesoporous SiO_2 on tribological properties and rheological properties of lithium grease were investigated by Anton-paar NHT3 nano-indentation tester and Anton-paar MCR302 rotary rheometer. The results show that the spherical nanomesoporous SiO_2 additive reduced the tribological coefficient more effectively, strengthened the skeleton stability,enhanced the thixotropy, anti-shear ability and thermostability of greases. Under low and moderate shear rate, the rheological experimental data was fitted, and a new grease rheological model was proposed, containing nanoparticals mass concentrations parameter.