Assessment on tribological responsiveness of different polymers on AISI 52100 steel using a sensitive reciprocating tribometer

Abstract

Bio-based lubricants are becoming more prevalent in the lubrication sector to substitute the traditional petroleum based. In the current study, jatropha oil was used as the base lubricant with polytetrafluoroethylene (PTFE) and organic Eichhornia crassipes-carboxymethylcellulose (EC-CMC) polymers as additives. The research employed a sensitive reciprocating apparatus to examine the tribological responsiveness of the formulation on AISI 52100 steel material in terms of coefficient of friction (COF), wear rate, wear scar diameter, and surface roughness (Ra). Polymeric and Fourier transform infrared spectroscopy studies were conducted on the formulations. The findings indicate that both additives in jatropha in concentrations produced higher COF than unmodified jatropha oil at 100 and 250 r/min under low load (15 N), but improved performance under higher load (35 N). Under wear rate examination, the formulations demonstrated a slight reduction under higher working conditions; however, the 0.5 wt% EC-CMC blended sample performed poorly in terms of both COF and wear rate. In the research, 0.4 wt% PTFE and 0.3 wt% EC-CMC produced the best outcomes for their respective categories. The nano lubricant exhibited remarkable performance when tested under more demanding working conditions (500 r/min and 45 N) but performed better when 0.4 wt% PTFE was utilized, which is comparable to the reference commercial shell lubricant used. The ability of the nano lubricants to penetrate and generate some films at the sliding contact during operation shows their enhanced performance at higher operating conditions, which was supported by the results of the energy-dispersive X-ray study.