Synergistic tribological effect between polyisobutylene succinimide-modified molybdenum oxide nanoparticle and zinc dialkyldithiophosphate for reducing friction and wear of diamond-like carbon coating under boundary lubrication  

作　　者：Shuoshuo CHEN Ningning SONG Shengmao ZHANG Yujuan ZHANG Laigui YU Pingyu ZHANG 

机构地区：[1]National&Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials,Henan University,Kaifeng 475004,China

出　　处：《Friction》2023年第11期2021-2035,共15页摩擦（英文版）

基　　金：support provided by the National Natural Science Foundation of China(Nos.51875172 and 52105180);Zhongyuan Science and Technology Innovation Leadership Program(No.214200510024).

摘　　要：Organic molybdenum lubricant additive like molybdenum dialkyl dithiocarbamate(MoDTC)can cause wear acceleration of diamond-like carbon(DLC)coating coupled with steel under boundary lubrication,which hinders its industrial application.Therefore,polyisobutylene succinimide(PIBS),an organo molybdenum amide,was adopted to modify molybdenum oxide affording molybdenum polyisobutylene succinimidemolybdenum oxide nanoparticles(MPIBS-MONPs)with potential to prevent the wear acceleration of DLC coating.The thermal stability of MPIBS-MONPs was evaluated by thermogravimetric analysis.Their tribological properties as the additives in di-isooctyl sebacate(DIOS)were evaluated with MoDTC as a control;and their tribomechanism was investigated in relation to their tribochemical reactions and synergistic tribological effect with zinc dialkyldithiophosphate(ZDDP)as well as worn surface characterizations.Findings indicate that MPIBS-MONPs/ZDDP added in DIOS can significantly reduce the friction and wear of DLC coating,being much superior to MoDTC.This is because MPIBS-MONPs and ZDDP jointly take part in tribochemical reactions to form a composite tribofilm that can increase the wear resistance of DLC coating.Namely,the molybdenum amide on MPIBS-MONPs surface can react with ZDDP to form MoS2 film with excellent friction-reducing ability;and MPIBS-MONPs can release molybdenum oxide nanoparticle to form deposited lubrication layer on worn surfaces.The as-formed composite tribofilm consisting of molybdenum oxide nanocrystal,amorphous polyphosphate,and molybdenum disulfide as well as a small amount of Mo2C accounts for the increase in the wear resistance of DLC coating under boundary lubrication.

关 键 词：molybdenum oxide nanoparticle zinc dialkyldithiophosphate(ZDDP) synergistic tribological effect diamond-like carbon(DLC)coating boundary lubrication wear resistance 

分 类 号：TE667[石油与天然气工程—油气加工工程]