复合锂基润滑脂的流变特性与微观结构的关系研究

摘要

对5种复合锂基脂样品进行流变性测试，研究流变特征参数与样品的微观结构的关系。结果表明，复合锂基润滑脂的流变特性与体系的微观结构有关，其中流动转变指数可以描述润滑脂内部结构的破坏行为，其值越大，复合锂基脂的皂纤维结构越好；损耗系数小时复合锂基脂的脆性大，损耗系数大时复合锂基脂更容易铺展；在恒定剪切速率下，复合锂基脂的皂纤维结构越致密均匀，在剪切的过程中相对黏度下降率越小。通过测定润滑脂的流变特征参数，可以描述复合锂基润滑脂结构的稳定性和受破坏的程度，对于润滑脂的研发和使用有一定的指导意义。%The rheological propertiess of five lithium complex lubricating greases were tested.The relationship between rheological properties and microstructure of the five greases was investigated.The results show that the rheological proper-ties of lubricating greases are related to their microstructure,among which the flow transition index can characterize the failure behavior of inner structure of grease,and the lithium complex greases with greater flow transition index have better soap fiber structure.The lithium complex greases with small damping factor have lager brittle character,and the lithium complex greases with large damping factor can spread more easily.At a constant shear rate,the complex lithium greases with dense and uniform soap fiber structure have small relative viscosity decline rate during shearing process.Through test and determining the rheological property parameters,the stability and the degree of damage of the structure of lithium com-plex lubricating greases can be characterized.