Improved lubrication performance of MoS2-Al2O3 nanofluid through interfacial tribochemistry
Improved lubrication performance of MoS2-Al2O3 nanofluid through interfacial tribochemistry
复制标题
通过界面摩擦化学改善MoS2-Al2O3纳米流体的润滑性能
DOI：
10.1016/j.colsurfa.2021.126428
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发表时间：
2021-03-19
影响因子：
5.2
通讯作者：
Wu, Ping
中科院分区：
文献类型：
--
作者：
He, Jiaqi;Sun, Jianlin;Wu, Ping
含有纳米复合材料的纳米流体在润滑领域具有广阔的应用前景。采用溶剂热法制备了MoS 2-Al 2 O3纳米复合材料。制备了含MoS 2-Al 2 O3纳米粒子的水基纳米流体，其稳定性和润湿性最佳。研究了MoS 2-Al 2 O3纳米流体在钢/钢接触条件下的摩擦学性能。通过对磨损表面的化学分析，研究了摩擦界面上发生的摩擦化学反应和摩擦膜的形成，揭示了润滑机理。结果表明，MoS 2-Al 2 O3纳米流体对摩擦副的摩擦力和磨损率有显著的降低作用。纳米粒子在摩擦界面的进入和运动是其上级润滑性能优异的部分原因。更重要的是，由于界面摩擦化学作用，在金属表面形成了由吸附层和反应层组成的双层结构的摩擦膜，阻止了钢表面的直接接触。吸附膜的厚度约为16 nm的占主导地位的非晶衬底和晶体相（超细Al 2 O3和MoS 2碎片）嵌入在顶部。吸附膜下的反应层含有高机械性能的铁氧化物（主要是Fe 3 O 4和Fe 2 O3）和自润滑的Fe 2（SO 4）3，进一步减轻了摩擦，提高了材料的耐磨性。
Nanofluids containing nanocomposite materials have broad application prospect in lubrication. In the present study, MoS2-Al2O3 nanocomposite was synthesized by solvothermal method. Then water-based nanofluid containing MoS2-Al2O3 nanoparticles was prepared and it exhibited optimal stability and wettability. The tribological properties of MoS2-Al2O3 nanofluid under steel/steel contact were investigated. Through chemical analysis of worn surface, tribochemical reactions occurred and tribofilm generated at friction interface were studied to reveal the lubrication mechanism. The results showed that MoS2-Al2O3 nanofluid exhibited outstanding effect on reducing the friction force and wear rate of friction pairs. The superior lubrication performance was partly attributed to the entry and movement of nanoparticles at friction interface. More importantly, due to interfacial tribochemistry, a tribofilm with double layer structure composed of adsorption film and reaction layer was formed on the metal surface, preventing the direct contact of steel surfaces. The adsorption film with a thickness of about 16 nm was predominated by amorphous substrates and crystal phases (ultrafine Al2O3 and MoS2 debris) embedded in the top. And the reaction layer beneath adsorption film contained high mechanical properties iron oxides (mainly Fe3O4 and Fe2O3) and self-lubricating Fe2(SO4)3, which further alleviated friction and enhanced the wear-resistance of materials.