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

The properties of extreme pressure, antiwear, friction reduction of four 2,5-dialkoxymethylthio-1,3,4-thiadiazole 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 FeSO4 were formed on the rubbed surface. (C) 1998 Published by Elsevier Science S.A. All rights reserved.