高碱值硫化烷基酚钙盐摩擦膜的XANES研究

X-Ray Absorption Near Edge Structure Spectroscopy Study of Tribofilms from Overbased Phenate

本文利用碳的K-边、钙的L-边和硫的K-边和L-边X射线吸收精细结构光谱(XANES)系统研究了高碱值烷基酚盐润滑下摩擦膜的表面化学结构。摩擦学实验在高频摩擦磨损试验机上进行,结果表明,高碱值烷基酚盐具有一定的抗磨性能,其原因在于摩擦导致清净剂胶体结构被破坏,释放的碳酸钙纳米颗粒沉积在表面上形成摩擦膜,从而降低了材料的接触,起到抗磨作用。

The chemical contents of the tribofilrns, originated from overbased calcium phenate umder boundary lubrication, were characterized with sulfur, calcium and carbon X-ray absorption near edge structure spectroscopy （XANES）. The boundary lubrication was realized with a dedicated pin-on-disk reciprocating wear tester. The S, K-edges and L-edge of the XANES spectra show that when high-overbased detergents are used, micelles containing calcium carbonate decompose. The C, K-edges of the XANES spectra reveal that the calcium carbonate deposits in the tribofilms. The tibofilms, containing nano-particles of calcium carbonate, form possibly because the friction results in decomposition of the detergent molecules, and the released calcium carbonate deposit on substrate surface, forming tribofilms in between, which in turn lower the friction.