Static friction tests with various metal combinations and special lubricants

Abstract

An in clined-plane apparatus was used in obtaining static friction data for various lubricants with different metal combinations. Special lubricants, s uch as ch lorinated and fluorinated hydrocarbons, were compared with a reference mineral oil. The effect of addi-tives, s uch as graphite, molybdenum di sulfide, zinc oxide, boron nitride, and an oxidized petroleum compound, was investigated. Metal combinations involving stainless steels, carbon steel, cast iron, aluminum alloy, and chromium plate we re used. It was found that the special chlorinated and fluorinated lubricants without additives gave higher friction than the Navy symbol 2110 reference oil. A lubricant containing the oxidized petroleum compound and one containing a silicone grease gave slightly less friction than the reference oil. With a mineral lubricating grease, with dry molydenum disulfide, and with lubricants containing graphite or molybdenum di sulfid e, the friction was about 50 percent less than with -the reference oil. The remaining lubricants gave higher friction than t he 2110 reference oil. In general, the heat-treated stainless-steel combinations gave the lowest friction, whereas the combinations involving cast iron or aluminum alloy gave relatively high friction. Fric-t~on was less with lapped and polished surfaces than with ground s urfaces.