Investigation of tribological behaviours of graphene-coated journal bearing

Yıldız, Bayram
In this study, we investigated macro- and nano-scale tribological behaviours of single-layer graphene on steel parts. Single layer graphene was synthesized via Chemical Vapour Deposition (CVD) on copper foil and then transferred onto commercial journal bearing that has a considerable rough surface. Nanotribological tests were carried out by using Atomic Force Microscopy (AFM) under loadings differs from 5 to 30 nN, and macrotribological experiments were done using pin on disc type tribometer at three different loads of 10, 15 and 30 N within 90, 120 and 250 s sliding cycle durations. The results exhibited that graphene effectively diminish the wear rate of substrate material, whereas it has no significant improvement in coefficient of friction due to high asperity of surface. The worn surface analyses were characterized by scanning electron microscopy for the evaluation of wear mechanisms.


Investigation of bismuth doped bioglass/graphene oxide nanocomposites for bone tissue engineering
Pazarçeviren, Ahmet Engin; Tezcaner, Ayşen; Keskin, Dilek; Evis, Zafer (2018-03-01)
In this study, bismuth doped 45S5 nanobioactive bioglass (nBG) and graphene oxide (GO) nanocomposites were developed and characterized in terms of microstructural, mechanical, bioactivity and biological properties. Bismuth (Bi) - doped nBG was synthesized by sol-gel method and sintered at 600 degrees C for 2 h. Nanosized GO was homogeneously mixed with Bi doped bioglass at various ratios to prepare nanocomposites. Addition of Bi increased the density of nBG samples while a considerable decrease in density w...
Comparison of conventional and collapsed region operation of capacitive micromachined ultrasonic transducers
Huang, Yongli; Haeggstrom, Edward; Bayram, Barış; Zhuang, Xuefeng; Ergun, Arif Sanh; Cheng, Ching-Hsiang; Khuri-Yakub, Butrus T. (2006-10-01)
We report experimental results from a comparative study on collapsed region and conventional region operation of capacitive micromachined ultrasonic transducers (CMUTs) fabricated with a wafer bonding technique. Using ultrasonic pulse-echo and pitch-catch measurements, we characterized single elements of 1-D CMUT arrays operating in oil. The experimental results from this study agreed with the simulation results: a CMUT operating in the collapsed region produced a higher maximum output pressure than a CMUT ...
Preparation and characterization of cost effective spray pyrolyzed absorber layer for thin film solar cells
Sankir, Nurdan D.; Aydin, Erkan; Unver, Hulya; Uluer, Ezgi; Parlak, Mehmet (Elsevier BV, 2013-09-01)
In this study, highly (1 1 2) oriented crystalline copper indium disulfide (CuInS2) thin films with high mobility have been deposited via ultrasonic spray pyrolysis. Structural and electrical properties of CuInS2 thin films were examined to utilize them in solar cell applications. Various amounts of precursor solution ranging from 0.25 to 2.02 ml/cm(2) were used to form CuInS2 thin films onto the soda lime glass substrates. Scanning electron microscopy (SEM) analysis revealed that all sprayed films were pin...
MAKSZIMUS, Andrea; GACSI, Zoltan; Gür, Cemil Hakan (2007-10-16)
The purpose of this study is to find a relationship between the parameters describing the microstructural homogeneity of SiC particle reinforced Al metal matrix composites. The Al-SiC powder mixtures having different particle size combinations were hot-pressed after careful mixing. The optical microscope images of the microstructures were processed by using an image analyzing program; the binary morphology was chosen for characterizing the SiC particle distribution.
Investigations on bulk glass forming ability of titanium based multicomponent alloys
Süer, Sıla; Mekhrabov, Amdulla O.; Department of Metallurgical and Materials Engineering (2008)
The aim of this study is to investigate the bulk glass forming ability (BGFA) of Ti-based alloy systems. These investigations were carried out in two main parts that are complementary to each other: theoretical and experimental. For theoretical studies, which are based on electronic theory of alloys in pseudopotential approximation, Ti-Zr, Ti-Co and Ti-Cu alloys were chosen as the binary systems. Alloying element additions were performed to each binary for the investigation of the BGFA of multicomponent Ti-...
Citation Formats
B. Yıldız, İ. OVALI, and C. G. ÜNLÜ, “Investigation of tribological behaviours of graphene-coated journal bearing,” TRIBOLOGY-MATERIALS SURFACES & INTERFACES, pp. 177–185, 2018, Accessed: 00, 2020. [Online]. Available: