Tribological properties of attapulgite clay as lubricant additive for steel-steel contacts

The attapulgite clay powder was dispersed in CD15W-40 mineral oil as lubricant additive. The tribology properties under the lubrication of base oil with diversity concentration of attapulgite clay powder were investigated on a standard optimal SRV-IV tribometer. The elemental component and morphology on worn surface were analyzed by SEM coupled with EDS. The results show that, the resultant lubricant containing 0.4% attapulgite clay made friction coefficient to decrease 14.29%, the wear rate of contacts decreases observably as high as 59.94%; a more smooth and compact tribofilm of which more oxides has been formed on the worn surface is obtained. The layer-chain crystal structure of attapulgite clay and the complex physicochemical in proceeding friction process is the main reason of decreasing the friction and wear of the tribopair.