Lubrication of dry sliding metallic contacts by chemically prepared functionalized graphitic nanoparticles  

作　　者：Suprakash SAMANTA Santosh SINGH Rashmi R.SAHOO 

机构地区：[1]Surface Engineering&Tribology Division,CSIR-Central Mechanical Engineering Research Institute,Durgapur 713209,India [2]Academy of Scientific and Innovative Research(AcSIR),Ghaziabad 201002,India

出　　处：《Friction》2020年第4期708-725,共18页摩擦（英文版）

基　　金：The authors are grateful to CSIR,India for the grant through 12FYP project ESC-0112 in carrying out this work.

摘　　要：Understanding the mechanism of precision sliding contacts with thin, adherent solid nano lubricating particle films is important to improve friction and wear behavior and ensure mechanical devices have long service lifetimes. Herein, a facile and multistep approach for the preparation of graphene oxide (GO) is presented. Subsequently, surface modification of as-synthesized GO with octadecyl amine (ODA) is performed to prepare hydrophobic GO-ODA and with 6-amino-4-hydroxy-2-naphthalenesulfonic acid (ANS) to prepare amphoteric GO-ANS through a nucleophilic addition reaction. X-ray diffraction and ultraviolet-visible, Fourier transform infrared, and Raman spectroscopy provide significant information about the reduction of oxygen functionalities on GO and the introduction of new functionalities in GO-ODA and GO-ANS. The effects of particle functionalization for the improved control of particle adhesion to the tribocontact have been studied. Wettability and thermal stability were determined using the water contact angle, and atomic force microscopy and differential scanning calorimetry (DSC) were used to characterize particle adhesion to the tribocontact. The tribological performances of the particles have been investigated using macro- and micro-tribometry using pin/ball-on-disc contact geometries. The influence of particle functionalization on the contact pressure and sliding velocity was also studied under rotating and reciprocating tribo-contact in ambient conditions. With an increase in the contact pressure, the functionalized particles are pushed down into the contact, and they adhere to the substrate to form a continuous film that eventually reduces friction. Amphoteric GO-ANS provides the lowest and most steady coefficient of friction (COF) under all tested conditions along with low wear depth and minimal plastic deformation. This is because particles with superior wetting and thermal properties can have better adherence to and stability on the surface. GO-ANS has a superior ability to adhere on the track to f

关 键 词：solid lubricants NANOPARTICLES carbon GRAPHITE sliding friction and wear ADHESION electron microscopy 

分 类 号：TB383.1[一般工业技术—材料科学与工程]