Process For Applying Lubricants Containing Metal Nanoparticles on Interacting Parts

Abstract

A process for applying a low coefficient of friction coating to interacting parts of a machine. The low coefficient coating is comprised of nanoparticles of a metal melting below about 400° C., preferably bismuth. A dispersion of the nanoparticles in a lubricant oil is introduced into the oil reservoir of the machine and the machine is operated at designed conditions.

What is claimed is: 
     
         1 . A process for applying a low coefficient of friction coating on interacting parts of a machine designed for being lubricated with a lubricating oil and having a reservoir for storing and providing lubricating oil, which process comprises: i) dispersing about 0.001 wt. % to about 2 wt. % of nanoparticles of one or more metals having a melting point less than about 400° C. with a lubricating oil; ii) introducing said dispersion into the reservoir of a machine; and iii) operating the machine under operating conditions for an effective amount of time to form a nano-coating on at least a fraction of the interacting parts of the machine. 
     
     
         2 . The process of  claim 1  wherein the metal is selected from bismuth, cadmium, tin, indium, and lead. 
     
     
         3 . The process of  claim 2  wherein the metal is bismuth. 
     
     
         4 . The process of  claim 5  wherein the mean particle size of the metal nanoparticles is from about 2 to 60 nm. 
     
     
         5 . The process of  claim 1  wherein the lubricant is selected from lubricating oils and greases. 
     
     
         6 . The process of  claim 5  wherein the lubricant is a lubricating oil. 
     
     
         7 . The process of  claim 6  wherein the lubricating oil is a natural lubrication oil. 
     
     
         8 . The process of  claim 6  wherein the lubricating oil is a synthetic lubricating oil. 
     
     
         9 . The process of  claim 1  wherein the machine is one that powers a transportation vehicle. 
     
     
         10 . The process of  claim 1  wherein the machine is an engine for a military vehicle. 
     
     
         11 . The process of  claim 3  wherein the machine is an engine for a military vehicle.