A rheological model for lithium lubricating grease

The rheological properties of a lithium lubricating grease were examined under various settings of shear rate, time and temperature with an emphasis on the thixotropy of grease. A HAAKE RV 20 rheometer was employed in the experiments, utilizing a cone and plate configuration, Precautions were taken when scheming and carrying out the test in order to eliminate the effects of slip at the wall, fracture and other forms of disturbance. Flow curves and thixotropic hysteresis loops were obtained. Based on the measurement results, a new rheological model involving a structural parameter has been proposed. The characteristics of the proposed model and its implication for lubrication analysis were discussed. (C) 1999 Elsevier Science Ltd. All rights reserved.