Evaluation of Rheological and Tribological Properties of African Pear Oil (Atile) As an Eco-friendly Alternative to Conventional Lubricants for Grass-cutting Machines

Abstract

This study aims to evaluate the rheological and tribological properties of African pear oil (Atile) as an eco-friendly alternative to conventional lubricants in grass-cutting machines. The raw material Atiles’s fruits of 5 kg were collected at Akwanga Nasarawa state, Nigeria. The viscosity, specific gravity, and wear rate of Atile oil blended with engine oil were determined to assess their suitability for mechanical applications. Viscosity tests conducted at 30°C and 60°C revealed that Atile oil exhibited significantly lower viscosity values compared to 100% engine oil, with notable changes in viscosity across varying shear rates (6 rpm, 12 rpm, and 30 rpm). The blends of 40/60 (Engine/Atile) and 60/40 (Engine/Atile) demonstrated improved viscosity stability, making them viable candidates for lubrication in grass-cutting machines. Specific gravity measurements indicated that Atile oil (100%) had a higher density (0.9090 g/cm³) compared to engine oil (0.8786 g/cm³), which is indicative of its higher molecular structure. Tribological tests on wear rate showed that the Atile oil blends displayed lower wear rates compared to pure engine oil, with the 60/40 (Engine/Atile) blend exhibiting the best wear resistance. Wear resistance, calculated from volume loss and sliding distance, confirmed that Atile oil blends had promising anti-wear properties, with the 60/40 (Engine/Atile) blend demonstrating superior wear resistance. The results suggest that Atile oil, particularly in combination with engine oil, can serve as an effective, environmentally friendly alternative to conventional lubricants, offering both optimal rheological and tribological performance for grass-cutting machines.