기계공학부 구성원들의 많은 관심과 참여 부탁 드립니다.

▣ 주   제: Tribological Performance of Innovated Reduced Graphene Oxide Suspended as Additive in Engine Commercial Oil

▣ 연   사: Prof. Kaleli

▣ 소   속: Yildiz Technical University

▣ 일   시: 2022. 9. 15.(Thu) 11:00

▣ 장   소: 제4공학관 D601호 

▣ 초   청: 김대은 교수

▣ 초   록

Good dispersion stability of engine oil added with graphene is the premise of playing its superior tribology property and also the novelty of this study. In this work the tribological behavior of a commercialized, fully synthetic engine oil (Shell 5W-40) upon the incorporation of rGO in seven different contents (0.2, 0.1, 0.08, 0.06, 0.04, 0.02 and 0.01 wt.%) was investigated. Stability of the prepared samples was assessed by turbidimetry and dynamic light scattering (DLS) measurements, as well as their tribological properties through a reciprocating tribometer, using a steel ball (100 CR6 or 52100) on special cut steel blocks (Sverkel 21-AISI D2). The addition of rGO 0.02 wt.% led in tribological behavior improvement compared to the pristine engine oil, by significantly lowering friction coefficient (COF) by ~5% (from 0.09887 to 0.09433) in the boundary-mixed lubrication regime. Both the surfaces and rGO additive were thoroughly characterized by microscopic and optical spectroscopy techniques. As the tribological behavior of a commercialized, fully synthetic 5W40 engine oil upon the incorporation of reduced graphene oxide in sample (0.02 wt.%) like (5W40 engine oil+ 0.02 wt.% Reduced Graphene Oxide) called rGO6 presented superior tribological properties by exhibiting the lowest COF value in our previous work, the same sample was evaluated through a reciprocating tribometer, using steel ball (100 CR6) on a real polished gasoline engine cylinder liner with 5W-40 engine oil to investigate their wear and friction behavior in boundary lubrication regime. It was found that a rGO6 nano-additive played an active role in lowering the coefficient of friction (%3.29) and increased surface protection by forming a protective layer on a smooth nanorough on rubbing surfaces.