Analysis of Oil and Oil with Graphite Lubrication on Sliding Wear Behavior of Bronze Filled PTFE Composites

In this present work the tribological properties of composite materials considering various conditions are experimentally determined by using pin on disc tribometer (TR-20) DUCOM make, Bangalore. Work has been carried out by considering three velocities in the range of 0.5 m/s to 2.0 m/s and loads varying from 15.7 N to 45.1 N keeping rest of the parameters constant. The test has been carried out for three materials pure PTFE, PTFE + 40% Bronze and PTFE + 60% Bronze in wet and adding additive as graphite in oil. Graphite with 5% by weight is added in the lubricating oil. Graphite with 2030 μm diameter is used in the test. The oil used for wet condition is SAE20W40. The counter surface used is EN8 with surface finish of 0.56μm. The results are tabulated and graphs are plotted. It has been found that, load and wet conditions has significant effect on coefficient of friction and specific wear rate of the material. Where as sliding velocity also plays little role in wear mechanism of the material. It can be concluded from the results that, PTFE shows best tribological properties under wet condition than in dry and oil with adding 5% graphite as an additive. From overall observations, PTFE+40%Bronze polymer is having good wear resistance than pure PTFE and PTFE+60% Bronze composite in dry condition. Also results shows that material PTFE+60%Bronze Polymer is having good tribological properties than pure PTFE and PTFE+40%Bronze Polymer in oil lubrication with 5% wt. graphite as an additives in oil. The mathematical modeling has been carried out by using multiple regression analysis, total six models have been developed and based on the value of regression coefficient the best model has been selected and it is found to be valid for the above tested parameters.