Effect of extreme contact load under two different rotational speeds on reduced phosphorus plain ZDDP oil in the presence of 1 per cent FeF3 catalyst

Abstract

Friction and wear performance of FeF3 catalyst in plain and fully formulated oils is pursued in two areas. First, it explores the tribological testing and interactions of several oil blends and provides equations for the fully formulated and plain zinc dialkyl dithiophosphate (ZDDP) oil using design of experiment (DOE) under steady-state rotational speed of 700 r/min (the test was run under 700 r/min until it reaches 100 000 revolutions or failure, whichever comes first) and extreme contact load of 2.72 GPa. Second, lower phosphorus plain ZDDP oil was targeted with the addition of 1 per cent FeF3 catalyst since the DOE responses and equations provided significant evidence that FeF3 catalyst improved the wear performance and extended the failure time in plain ZDDP oils. Scanning electron microscopy coupled with energy dispersive spectroscopy, transmission electron microscopy, and Auger electron spectroscopy were used to study the wear track, wear debris, and tribofilm formation of 0.1 per cent P (phosphorus) plain ZDDP oil + 1 per cent FeF3 catalyst and 0.05 per cent P (phosphorus) plain ZDDP oil + 1 per cent FeF3 catalyst under two different rotational speeds (lower stage of 100 r/min for the first 5000 revolutions and a higher stage of 700 r/min until failure or 100 000 revolutions, whichever comes first) and extreme Hertzian contact pressure of 2.77 GPa or 405 N. Results show a significant improvement when 1 per cent FeF3 catalyst is used in 0.05 per cent P plain ZDDP oil and it correlates closely with the experimental results of the DOE.