A Comparative Experimental Analysis of Tribological Properties Between Commercial Mineral Oil and Neat Castor Oil using Taguchi Method in Boundary Lubrication Regime

The present work aims to carry out a comparative experimental analysis of tribological properties of 372cSt mineral oil and 229cSt castor oil. The antiwear and extreme pressure properties of both the oils have been analysed according to ASTM G 99 and ASTM D-2783 standards. The surfaces of the balls and pins after tribo tests have been analysed using Scanning Electron Microscope (SEM) images. The present test results predict that the antiwear and extreme pressure properties in case of the selected commercially available mineral oil are better than neat castor oil. Both coefficient of friction and frictional force increased by 16-42 % and 16-35 % respectively in case of neat castor oil as compared with that of the mineral oil. The load carrying capacity in case of mineral oil has been found to be 250 kg while in case of castor oil it has been found to be 126 kg. SEM images show a higher plastic deformation in case of castor oil as compared to the mineral oil. Both mineral oil and castor oil showed surface deteriorations and increase in roughness after 40 hrs of intermittent running during scuffing test. Thus, the present investigation indicates that the tribological properties of neat castor are inferior to that of mineral oil although close observation of the results shows that both AW and EP properties of neat castor oil are much closer to that of commercial mineral oil. Thus, the present work would help in formulating castor oil based new bio lubricants with better anti wear and extreme pressure properties.