Friction and Wear Studies for Bonded Thin-Film Lubricants.

摘要

Bonded dry-film lubricants were evaluated to select a suitable lubricant for use in electromechanical devices which must be highly reliable after extended periods of storage and exposure to extreme atmospheric conditions. Mechanism tolerances and clearances require that the bonded lubricants be applied in thin films from 0.0002to 0.0005inch in thickness and that they exhibit a low friction coefficient both at the light loads of ambient environments and the loads of high-g environments. A tribometer,needed to obtain friction data by several techniques from dry-film-lubricant samples at light and moderate loads,was developed,since a suitable instrument was not commercially available. Light-load friction and wear characteristics were determined for ten commercially available,bonded dry-film lubricants. Of the six lubricants originally evaluated, Electrofilm 4396was judged to be the best of the group. A later preliminary study of four other lubricants revealed that Electrofilm 77S may be better than 4396for use in the small precision electromechanical devices. After tests on the original six lubricants found 4396to be superior, a factorial design experiment used it to find the interaction between such friction-influencing variables as substrate finish and hardness,mating-part finish and hardness,and film polishing. Light-load-coefficient and wear-life data were compiled for Electrofilm 77S, 4396,and 4396S bonded dry-film lubricants. Static and dynamic friction performance were studied using the tribometer specially designed to test bonded films,and mean and standard deviations were calculated for comparison. The data indicated that Electrofilm 77S was the best lubricant for light-load applications. (ERA citation 02:018032)