Lubricating Ability of Magnesium Silicate Hydroxide–Based Nanopowder as Lubricant Additive in Steel–Steel and Ceramic–Steel Contacts

Abstract

The friction and wear of sliding surfaces are responsible for important energy losses and negative environmental effects. Magnesium silicate hydroxide–based nanopowder (KM) is an antiwear and self-recovery material that could be applied in the lubricating subsystem of mechanical components. This study investigates the ability of KM to reduce friction and improve the wear resistance of sliding steel surfaces. A ball-on-flat reciprocating tribometer was used with steel–steel contact to evaluate the lubricating ability of KM as an additive in a commercially available motor oil. Experimental results show that by adding 0.23 wt% of KM to the motor oil, friction and wear can be reduced up to 45 and 40%, respectively, under the longer distance studied. In addition to ball-on-flat tests, a bearing test rig was used to investigate the antiwear behavior of KM as an additive in a commercial high-speed grease. Ball bearings of steel–steel and steel–ceramic contacts were lubricated with a high-speed grease. The addition of 0.4 wt% of KM to the grease improved the durability and reduced the ring wear. Optical microscopy, noncontact 3D profilometry, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were utilized to analyze and discuss the wear mechanisms and surface interactions.