Conversion of used engine oils from agricultural machinery into colloidal graphite greases enhanced lubricating greases
نویسندگان
1 Tambov State Technical University, Tambov, Russia.
2 College of Engineering, The Iraqia University, Baghdad, Iraq.
doi
10.22034/crl.2025.532873.1650چکیده
The article examines the development of a stable lubricant enhanced with colloidal graphite, utilizing recycled 15W40 diesel engine oil thickened with calcium soap. The study reveals that increasing the graphite concentration results in a gradual rise in water content, while the amount of thickener remains unchanged. Furthermore, higher graphite levels lead to a reduction in penetration values, decreasing from 440 units to 310 units. This suggests an improvement in grease consistency and stiffness. The dropping point also shows notable changes, increasing from 79°C to 88°C at a graphite concentration of 150 ppm, before declining to 81°C with further graphite additions. Regarding anti-wear performance, the smallest wear scar diameter is observed at the same 150 ppm concentration, measuring 0.215 mm—25.1% smaller than that of the control sample.
