Extreme pressure properties of garlic oil: comparative investigations with PAO4 base oil and PAO/garlic oil blend

This study aims at exploring the improvement in extreme pressure (EP) properties with addition of natural Garlic oil as EP additive. Comparative investigations were conducted on PAO4 base oil, Natural Garlic oil (NGO) and PAO(4) + 1 wt% NGO (Natural Garlic Oil) for evaluating the extreme pressure properties. The EP tests were conducted on a four ball tester according to ASTM D 2783. The results revealed that NGO possesses significantly good extreme pressure properties having a weld load of 3087N and load wear index of 513N. The results also revealed that NGO could significantly improve the weld load and load wear index of PAO(4) base oil. After adding 1 wt% garlic oil to PAO(4) the load wear index increased by 62.51% and weld load increased by 25%. This study proposes garlic oil as a replacement to the use of nano-particles as EP additives and aims to eliminate the disadvantages that are prominent with nano-particles without comprising the performance.