TOF-SIMS analysis of boundary films derived from calcium sulfonates

详细信息    查看全文

• 作者：Tomoo Kubo ; Satoko Fujiwara ; Hidetaka Nanao ; Ichiro Minami and Shigeyuki Mori
• 关键词：TOF ; SIMS ; boundary lubrication ; tribochemistry ; anti ; wear additives ; over ; based calcium sulfonate
• 刊名：Tribology Letters
• 出版年：2006
• 出版时间：August, 2006
• 年：2006
• 卷：23
• 期：2
• 页码：171-176
• 全文大小：472 KB

文摘

Tribological properties of over-based and neutral calcium sulfonate were examined under boundary lubrication conditions by using a ball-on-flat type tribo-tester. It was found that over-based calcium sulfonate reduced friction and wear of steel–steel contacts, whereas the neutral calcium sulfonate did not. It was found that boundary film composed of calcium oxide plays significant role on improving the tribological properties. Surface analyses by XPS and Time-of-flight secondary mass spectroscopy (TOF-SIMS) revealed that the major component of the film on upper surfaces is calcium carbonate and that at subsurfaces are composed of calcium oxide. A depth profile of the film obtained by TOF-SIMS using an etching technique revealed that thickness of the film is up to 240 nm. A static pyrolysis of the over-based calcium sulfonate on steel surface affords a thin film composed of calcium oxide, indicating that rubbing process is essential for the formation of the boundary film.