Rheological models for lithium and calcium greases

Abstract

This paper presents the investigation of the rheological properties and the microscopic structures of two common greases: UM185Li2 - lithium grease and U95Ca2 - calcium greases, with NLGI grade two.  The experimental apparatus used were a cone-and-plate rheometer for the rheological properties of the greases and an electronic microscope for the microscopic structures.  The results from the cone-and-plate rheometer have been fitted to seven different rheological models: Bingham, Herschel – Bulkley, Casson, Bauer, Balan, Pa-panastasiou and Dorier and Tichy models.   Finally, the microscopic structures of the greases have been correlated with their rheological properties.