The aim of this work is to study the rheological behaviors of carbon nanotubes (CNTs) as an additive on lithium
grease at different concentrations. The results indicated that the optimum concentrations of the CNTs was 2 %.
These experimental investigations were evaluated with a HAAKE Rheovisco RV20, Penetrometer and
Measurement of the dropping point. The results indicated that the shear stress and apparent viscosity increase
with the increase of CNTs concentration, penetration and consistency not effect of base grease, and the dropping
point increasing about 25%. The microstructure of CNTs and lithium grease was examined by high resolution
transmission electron microscope (HRTEM) and transmission electron microscope (TEM).