Influence of Adding CuO and MoS₂ Nano-particles to Castor Oil and Moulding Oil on Tribological Properties

The tribological properties of adding copper oxide (CuO) and molybdenum disulfide (MoS2) nanoparticles powder in both organic (castor oil) and mineral oil (moulding oil) were investigated. These properties include coefficient of friction and wear between two surfaces, CK50 steel alloy and 2024-T4 aluminum alloy. The Nano lubricants were prepared by dispersing CuO and MoS2 nanoparticle powders at variable weight fractions 0.3, 0.5, 0.7, 1.0 and 2.0% in each oil lubricant. The friction and wear tests were carried out using a pin on the disk test principle by the vertical universal friction testing machine (MMW-1A). The instability problem with the lubricant suspension was solved by adding different weight fractions of GUM ARABIC, which leads to 2% of it gives more stable suspensions. The best results from both friction and wear Tribo tests are observed in 1%W of adding both nanoparticles to both oil lubricants. The formation of Tribo film due to the adsorption and adherence of Nano additives on the surfaces was responsible in reducing the wear properties. Hybrid (1%Wt CuO + 1Wt% MoS2) nanoparticles that added to both oils indicates more decreasing in friction and wear compared to the base oil. The coefficient of friction for hybrid Nano-particulate lubricants reduced to 81.7% and 76.03%, while the wear rate reduced to 93.17% and 92.23% compared to castor oil and moulding oil respectively as a base oil. The study provides insights into how Nano-lubricant additives could contribute towards tribological enhancement and improved product quality.