China Petroleum Processing & Petrochemical Technology ›› 2021, Vol. 23 ›› Issue (3): 119-126.

• Lubrication Research • Previous Articles     Next Articles

Effect of Diesel Soot on the Distribution, Composition and Mechanical Properties of ZDDP Tribofilm

Feng Weimin; Song Hui; Song Ruhong; Yang Bingxun; Hu Xianguo   

  1. School of Mechanical Engineering, Hefei University of Technology, Hefei 230009
  • Received:2021-05-04 Revised:2021-06-18 Online:2021-09-30 Published:2021-09-27
  • Contact: Feng Weimin

Abstract: To investigate the effect of diesel soot on the distribution, composition and mechanical properties of ZDDP tribofilm. The HFRR tribometer was adopted to study the tribological performance. Worn surfaces lubricated with ZDDP and soot were analyzed by laser microscope, SEM/EDS, Raman spectroscopy, XPS and nano-indentation equipment. Results show that soot scrapes off ZDDP tribofilm and embeds into the worn surface, leading to the reduction of film thickness and non-uniform distribution of tribofim. The phosphate structure in ZDDP tribofilm changes from short chain pyrophosphate to long chain metaphosphate due to the increased contact stress caused by the soot abrasive wear promotes the cross-linking of ZDDP. The hardness (H) and elastic modulus (E) of the worn surfaces increase while the ratio of hardness to elastic modulus, H/E, decreases, which indicates the reduction of wear resistance caused by soot.

Key words: soot, ZDDP, tribofilm, chemical composition, mechanical properties