Abstract
The rheological properties of a solidified traction oil used in continuously variable transmissions (CVTs) under pressure were evaluated by observing large plastic deformation of metal microspheres (φ about 0.07 mm), occurring due to non-hydrostatic pressurization in the oil using a diamond-anvil pressure cell. The solidification pressure values obtained by observing aluminum sphere deformation were almost equal to those extrapolated from high-pressure viscosity; thus, aluminum sphere deformation experiments are effective for evaluating solidification pressure. Shear stresses of the solidified oils could be estimated up to 5 GPa from the deformed phosphor bronze spheres based on several assumptions. The obtained stresses were larger than those for Cu spheres and were almost equal to the mean shear stress obtained from a traction test.
