Some Measurements of High Pressure Lubricant Rheology

The advancement of the fields of elastohydrodynamic lubrication and high pressure metal forming in the past few years has focused attention on the need for reliable data of the variation of viscosity with pressure, temperature, and shear stress in well-defined fluids. This paper describes an investigation in which these effects were observed. The equipment used was a high pressure capillary-type viscometer which made possible the continuous variation of shear stress over a wide range at pressures up to 80,000 psi. Well-defined paraffinic and naphthenic base oils and several polymer blends of these oils were investigated as well as a polybutene, a diester, and two silicone fluids.