Experimental Study of the Lubrication Mechanism of Micro-Spherical Solid Particles between Flat Surfaces

Abstract

In this study, a novel apparatus was designed and constructed to perform micro-sliding friction experiments while simultaneously observing the motion of micro-sized spheres using a visual inspection technique. The apparatus comprises a precision elevation stage that is used to elevate a flat mica disk, with the microspheres on top of it, to bring it into contact with a stationary surface and apply low loads on the contact. During micro-sliding experiments, it was found that the velocity of the center of the microsphere was half the velocity of the mica disk; in addition, friction force measurements revealed a very low coefficient of friction (about 0.03), indicating the rolling motion of the microspheres. The main outcome of our study was the verification of the hypothesis that spherical particles can be used to avoid direct contact among flat surfaces and can also introduce rolling motion within the system. The pure rolling motion of the microspheres sandwiched between a stationary and a moving flat surface supports the idea of adding rigid spherical particles to oil lubricants to further reduce friction and wear in the system by performing as micro and nanoscale ball bearings.

Solid Lubricant in the Insect Leg Joints: Numerical Simulation of Tribological Properties

“…The results presented in this article may be of interest for the understanding of the functioning of lubricants based on solid and semi-solid particles, which are of undoubted applied interest and are being actively studied in the course of last years. [29,30] In this regard, given that many properties of living organisms are significantly superior to artificial ones, our bioinspired research looks promising, and mimicking of the described mechanisms could bring significant technological benefits.…”

Nanotechnology in Lubricants: A Systematic Review of the Use of Nanoparticles to Reduce the Friction Coefficient

“…Typically, the lubrication mechanism of nano-additives can be described to have four main effects: micro-bearing, protective film, polishing and repair effects [107][108][109][110][111]. The main mechanism of nano-additive lubrication highlighted in the reviewed studies is the micro-bearing effect.…”

Extremely Monodispersed Micrometer-Scale Spherical Particle Synthesis of Ag Inside a Microdroplet Vaporizing in Plasma

“…Consequently, the synthesized particles have excellent reproducibility. , In the present study, the environmental temperature was proactively controlled by pulse modulation of the applied power to generate an optimum environmental temperature that enabled the melting of Ag without evaporation in the plasma, thus achieving excellent reproducibility of the synthesized particles. Metallic particles with excellent monodispersibility may facilitate the development of applications such as ball spacer, microsized ball bearing, , and inks for printed electronics, as well as electrical, optical, and medical applications. Furthermore, this method can directly deposit particles from an inkjet nozzle onto a substrate, and the ability to adjust the adhesion position of synthesized particles on the spot may expand their application possibilities.…”