Investigation of the Applicability of Y2O3–ZrO2 Spherical Nanoparticles as Tribological Lubricant Additives

Abstract

Long-term environmental goals will motivate the automotive industry, component suppliers, and lubricating oil developers to reduce the friction of their tribosystems to improve overall efficiency and wear for increased component lifetime. Nanoscale ceramic particles have been shown to form a protective layer on components’ surface that reduces wear rate with its high hardness and chemical resistance. One such ceramic is yttria (Y2O3), which has an excellent anti-wear effect, but due to its rarity it would be extremely expensive to produce engine lubricant made from it. Therefore, part of the yttria is replaced by zirconia (ZrO2) with similar physical properties. The study presents the result of the experimental tribological investigation of nanosized yttria–zirconia ceramic mixture as an engine lubricant additive. Yttria-stabilized zirconia (YSZ) nanoparticle was used as the basis for the ratio of the ceramic mixture, so that the weight ratio of yttria–zirconia in the resulting mixture was determined to be 11:69. After the evaluation of the ball-on-disc tribological measurements, it can be stated that the optimal concentration was 0.4 wt%, which reduced the wear diameter by 30% and the wear volume by 90% at the same coefficient of friction. High-resolution SEM analysis showed a significant amount of zirconia on the surface, but no yttria was found.

Tribological Investigation of the Effect of Nanosized Transition Metal Oxides on a Base Oil Containing Overbased Calcium Sulfonate

“…Due to the high cost of Y2O3, the authors replaced part of it with zirconium dioxide. The synergistic effect between Y2O3 and ZrO2 was demonstrated when, together, the two oxide ceramic mixtures also resulted in a 90% reduction in wear [43]. Based on the results so far, it is worthwhile to continue researching Y2O3 nanoparticles for lubricating oil formulation, because they promise a very strong wear-reducing effect.…”

Analysis of the effect of machining parameters on the surface roughness in bore honing

“…An important area in manufacturing is the production of bores with good quality which are used in the internal combustion engine manufacturing for example. There is ongoing research to improve the functionality of machined surfaces by different methods, such as the use of special environmentally friendly additives in the lubricant between the contacting surfaces [1]; or the application of bio lubricants which improved the lubricating potentials by reducing the Coefficient of friction and wear rate [2]. However, the functional properties are still depending on the applied finishing procedure.…”

Study on the roughness parameters describing surface functionality in bore honing

“…This is caused by the fact that machine-induced anomalies on the surface greatly influences fatigue, corrosion, stress-corrosion, wear resistance et cetera [1]. There are ongoing researches to improve the functionality of machined surfaces by different methods, such as the use of special environmentally friendly additives in the lubricant between the contacting surfaces [2]. Though specific functionality-related properties can be effectively characterized and correlated with the surface texture parameters in practical production [3].…”