Friction evaluation of elastomers in lubricated contact

Abstract

Friction testing of elastomers in lubricated contact is discussed with a focus on developing experimental arrangements that can produce worthwhile results. Practical issues unique to elastomers are covered as well as their solutions, including contact mechanics, material response to loading, contact edges, oil absorption, cleaning and specimen geometry. A critique of reciprocating laboratory testing machines, including high-frequency short stroke and low-frequency long stroke friction and wear machines, is conducted for their usefulness, as is critical analysis of a wide variety of specimen confi gurations with the aim of helping the laboratory experimenter to overcome many of the pitfalls associated with testing of elastomers in lubricated conditions. Results from experiments using various testing arrangements are analysed, and it is found that the synthetic ester and mineral oil used produced similar results.

Temperature-dependent changes of physicochemical and tribological properties of acrylonitrile-butadiene rubber elastomer upon ageing in hexadecane and diethylene glycol dibutyl ether

“…15 Very low normal load can induce deformation of the elastomer, which indicates that their friction is related to the internal friction of the elastomer. 12 Consequently, the friction force exerted by an elastomer is mainly related to its bulk properties. 15 The friction force between the elastomer and hard counterface materials are commonly described as being comprised of a hysteresis and an adhesion component.…”

“…19 Previous tribological studies of NBR have been mostly focused on tests under dry friction conditions [20][21][22] and only a few investigations have been conducted on their frictional behaviors after ageing in lubricants. 12,13 Recently, Myant et al 23 reported how applied load and elastic properties of elastomers will influence the rolling and sliding friction of lubricated compliant contacts using a mini traction machine. However, most of the applications for nitrile rubbers are in those where the elastomer is exposed to different lubricating oils.…”

“…absorption of lubricant by the elastomer, leaching of constituents from the elastomer into the lubricant and chemical reaction between components in the lubricant and the elastomer. 12,13 Furthermore, the aged samples may lose elastomer chains and weakening/breaking of bonds between filler–elastomer may occur.…”