Synthesis and tribological behavior of novel Ag- and Bi-based composites reinforced with Ti3SiC2

This paper reports the synthesis and characterization of Bi-Ti3SiC2 and Ag-Ti3SiC2 composites. Novel composites were designed by adding 5 vol% (Ag-5%312Si or Bi-5%312Si), 10 vol% (Ag-10%312Si or Bi-10%312Si), 20 vol% (Ag-20%312Si or Bi-20%312Si), and 30 vol% (Ag-30%312Si or Bi-30%312Si) Ti3SiC2 particulates in the Ag and Bi matrix, respectively. SEM studies showed that Ti3SiC2 particulates are well dispersed in the metal matrix. The addition of Ti3SiC2 particulates enhanced the hardness and compressive yield strength of both the compositions. For example, Bi-70%312Si showed an enhancement in yield strength by ~1.7 times as compared to the Bi-matrix. Similarly, Ag-80%312Si showed an enhancement in yield strength by ~3.5 times as compared to the Ag-matrix. The addition of Ti3SiC2 particulates also had a positive effect on the tribological performance. The µmean decreased gradually from ~0.50 in Bi to ~0.41 in Bi-20%312Si. Similarly, µmean decreased gradually from ~0.38 in Ag to ~0.30 in Ag-30%312Si. The specific wear rate (WR) decreased by ~67 times in Bi-10%312Si as compared to the Bi-matrix. Similarly, the specific wear rate (WR) of Ag-20%312Si decreased by ~12 times as compared to the Ag-matrix. Detailed SEM studies showed that the tribological behavior is governed by the formation of tribofilms.