Y.X. Gao

Study on tribological properties of 2,5-dialkoxymethylthio-1,3,4-thiadiazoles

Abstract The properties of extreme pressure, antiwear, friction reduction of four 2,5-dialkoxymethylthio-1,3,4-thiadiazoles and the relations of their structure and tribological properties were evaluated using a four ball test machine, and compared with those of zinc butyloctyldithiophosphate (ZDDP) and amine salt of thiophosphate complex ester (T 307 ). The results indicate that these compounds possess excellent load carrying capacity, friction reduction and antiwear properties similar to those of ZDDP and T 307 under 300 N load, and they exhibit better antiwear properties than ZDDP and T 307 above 300 N load. The thermal stability and corrosive properties of these compounds were also investigated. The rubbed surfaces were investigated using electron probe microanalysis (EPMA) and X-ray photoelectron spectroscopy (XPS). Results of XPS analysis show that a boundary film mainly composed of thiadiazole complex, FeS and FeSO 4 were formed on the rubbed surface.

Study on 1,3,4-thiadiazole derivatives as novel multifunctional oil additives

The load-carrying capacity, friction reduction, and antiwear properties of two 1,3,4-thiadiazole derivatives added to liquid paraffin under boundary lubrication conditions were evaluated using a four-ball test machine. Their anticorrosive and antioxidative properties and thermal stability were also examined. The results when compared with those of zinc butyloctyldithiophosphate (ZDDP) show that the two novel compounds possess an excellent load-carrying capacity and better antiwear and antioxidative properties than ZDDP. In addition, they have good anticorrosive properties and high thermal stability. The rubbed surface was investigated using X-ray photoelectron spectroscopy and electron probe microanalysis. The extreme-pressure antiwear and antioxidation mechanisms are discussed.

Tribological properties of oleic acid — modified TiO2 nanoparticle in water

Abstract A cis -9-octadecenoic acid (OA) surface-modified TiO 2 nanoparticle with average diameter of 30 nm was chemically synthesized. The tribological properties of the prepared OA–TiO 2 nanoparticle as an additive in water were evaluated with a four-ball tester. The results show that the OA–TiO 2 nanoparticle exhibits good performance in wear and friction reduction as well as in load-carrying capacity. The maximum nonseizure load ( P B value) can be raised about six to ten times when 0.1–1.0% OA–TiO 2 nanoparticle was added into water.

Tribological properties of aqueous solution of imidazoline borates

The tribological properties of imidazoline borate at different concentration and different load in water were evaluated using a four-ball test machine. The tribological test results showed that the imidazoline borates have good load carrying capacity and lubrication property. The rubbed surfaces were investigated using X-ray photoelectron spectroscopy (XPS) and electron probe microanalyzer (EPMA). The results showed that imidazoline borates reacted with the metal surface in tribological process and produced a complex film, which is composed of organic imidazolines and partially decomposed products.