P. Hivart et al., A NEW FRICTION-SEIZURE TEST FOR PHOSPHATE STEARATE COATINGS USING CONDUCTIVITY MEASUREMENT, Lubrication engineering, 49(11), 1993, pp. 833-837
The test involves a rotating cylindrical specimen on which a semi-cyli
ndrical slider exerts localized pressure. The specimen and slider are
both insulated from holders and are connected to a direct current gene
rator. The occurrences of hydrodynamic lubrication, mixed lubrication
and seizure at slider-specimen coated interfaces are found to be well
related to coating conductivity and to local friction force via voltag
e and torque measurements vs. number of specimen revolutions. Evolutio
n of the above basic lubrication regimes is analyzed with the new test
procedures when considering different time values of acid pickling an
d aging first, phosphating treatment second and soaping third. It is c
learly shown that conductivity measurements are able to accurately den
ote the beginning of mixed lubrication and the onset of seizure when u
sing different time values for the above coating sequences.