Chemical Characterization of Surface Films Generated from Continuously Variable Transmission Fluids Using XAFS

An important function of belt-drive continuously variable transmission fluids (B-CVTFs) is to transmit engine torque between the belt and pulley. We studied the frictional properties of B-CVTFs using the reciprocating type of friction tester. To understand the mechanism of this torque transmission, the effects of the composition of the metal surface films on the metal frictional properties must be determined. This determination is difficult to do with electron probe microanalysis (EPMA), auger electron spectroscopy (AES), and x-ray photoelectron spectroscopy (XPS), the techniques that are usually used to investigate surface films.

This paper describes the chemical characterization of metal surface films generated by B-CVTFs using x-ray absorption fine structure (XAFS).