The formation mechanisms for auto-restoration tribofilm at the presence of palygorskite-Ag nanoparticles

ABSTRACT

This paper reports an investigation on the formation process and mechanisms of auto-restoration tribofilm at the presence of palygorskite-Ag nanoparticles (PAg-NPs). The mechanochemical and mechanophysical mechanisms for the formation of tribofilm are put forward according to the surface characterizations by employing the microscope, EDS and VG Multilab 2000(XPS). The results indicate that: 1) the auto-restoration tribofilm mainly consists of Fe₂O₃, Fe₃O₄, FeOOH, SiO₂, MgO, graphitic C and Fe; 2) the mechnochemical formation mechanism contains surface activation, bond breakage of PAg-NPs and mechnochemical or thermal reactions; 3) mechanophysical mechanisms include physical inlay, absorption, infiltration, and low-melt-point Ag filling mechanism.

KEYWORDS:

• Palygorskite
• ART
• tribofilm
• mechanochemical
• wear

Funding

This research was financially supported by the National Nature Science Foundation of China (Grant No. 50965004), Guizhou Province Science and Technology Foundation (Qiankehe J [2011] No. 2011), and Introducing Talent Funds Project of Guizhou University (No. (2013)10). We would like to express sincere gratitude to Prof. Liu Shirong for his help in the analysis of TEM, SEM, EDS and XPS.