INDICATORS OF LUBRICANT PERFORMANCE IN THE LABORATORY TESTING OF AN ENVIRONMENTAL-FRIENDLY METALWORKING FLUID

摘要

In this article, an environmentally friendly metal working fluid was used as test fluid. This fluid was used to determine what factors influence the repeatability of friction and wear results when a test method similar to ASTM D 6425 is used to evaluate lubricating oils. The repeatability was determined by comparing the coefficient of friction, the amount of wear and the wear scar surface appearance between repeat runs. It was found that repeatability improved when the sudden load increase as described in the test method (ASTM D 6425) was modified to a gradual load increase for the duration of the running-in period. It was also found that the amount of water vapour in the atmosphere influences repeatability. This was due to the formation of corrosion layers on the wear surfaces that involves water. The Optimol SRV 4 test rig was used as bench test for the friction and wear tests.