A study of the modification of the friction and wear behavior of polyphenylene sulfide by particulate Ag2S and PbTe fillers

Abstract

The tribological behavior of polyphenylene sulfide (PPS) reinforced with particulate inorganic fillers was studied. The composites were molded with Ag2S and PbTe fillers in varying proportions. Sliding tests were performed in a pin-on-disk configuration at a speed of 1.0 m/s, nominal pressure of 0.65 MPa, and counterface roughness of 0.1 μm Ra. The counterface was a hardened tool steel disk. Microscopic analysis of the transfer films formed on the counterface during sliding was performed. X-ray photoelectron spectroscopy (XPS) was used to analyze the compositions in the transfer film in the vicinity of the counterface. The As2S filler decreased the wear rate of PPS significantly while PbTe increased it considerably. The microscopic examination of the counterface surface showed that a thin, uniform and strongly adhering polymer transfer film was formed when Ag2S was used as the filler but there was little transfer film formed in the case of PbTe filler. XPS analysis revealed that chemical reaction occurred during sliding between the filler and the counterface Fe in the case of Ag2S while there was no such chemical reaction when PbTe was used as the filler. The chemical reaction in the case of Ag2S filler contributed to enhanced adhesion between the transfer film and the counterface and thus led to reduced wear.