Experimental investigation on thermo-physical properties of metal oxide composite nanolubricants

The thermal conductivity and dynamic viscosity of three different combinations of metal oxide composite nanolubricant had been investigated at different nanoparticle volume concentrations (0.02 to 0.1%) and different temperatures (303–353 K). The prepared Al2O3–SiO2, Al2O3–TiO2 and TiO2–SiO2 composite metal oxide nanoparticle was dispersed in Polyalkylene Glycol (PAG 46) lubricant by espousing the two-step preparation method. The thermal and viscosity experiment was performed using KD2 Pro Thermal Properties Analyzer and LVDV-III Rheometer, respectively. All the considered metal oxide composite nanolubricants were witnessed to behave as Newtonian fluids. A maximum viscosity enhancement of 20.50% recorded for Al2O3–TiO2/PAG nanolubricant with 0.1% nanoparticle volume concentration and at the temperature of 303 K. Whereas, the highest thermal conductivity improvement recorded for Al2O3–SiO2/PAG nanolubricant with 2.41% improvement at 0.1% nanoparticle concentration and temperature of 303 K. A new regression model to estimate the dynamic viscosity and thermal conductivity of metal oxide composite nanolubricants were proposed based on the finding obtained