Corrosion and lubricated sliding tribological behavior of Al-TiB2-nano Gr hybrid composites. (13th July 2018)

• Record Type: Journal Article
• Authors: Poria, Suswagata; Sutradhar, Goutam; Sahoo, Prasanta
• Is Part Of: Materials research express. Volume 5:Number 7(2018)
• Publication Date: 2018-07-13
• Subjects: Al composite -- TiB2 -- nano Gr -- corrosion -- lubricated sliding -- friction and wear; Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/aad07b
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: Corrosion and lubricated sliding tribological behavior of Al-TiB2 -nano Gr hybrid composites for varying wt% of reinforcements are studied. Composites fabricated in ultrasonic vibration assisted stir-cast method are characterized using optical micrographs and SEM images. Micro-hardness values of composites increases with incorporation of both TiB2 and nano-Gr bases while hardness decreases with addition of only nano-Gr phase. Corrosion characteristics are investigated using potentiodynamic polarization and electrochemical impedance spectroscopy measurements. Corrosion resistance of composites is tailored from the parameters like corrosion potential, corrosion current, linear polarization resistance. Results show that corrosion potential shifts to negative direction with incorporation of reinforcing phases. Nano-Gr intensifies the corrosion of aluminum base matrix through hindering the corrosion path. Presence of TiB2 phase does not alter that effect of nano-Gr. Formation of protective film on the surface of Al-2.5TiB2 -nano Gr composites is apprehended through impedance tests. The corroded surfaces are studied using SEM images and the morphologies reveal that localized corrosion occurs through formation of pit. Such localized corrosion is yielded by the formation of galvanic cell in between reinforcing phases (TiB2, nano-Gr) and base matrix in presence of electrolyte solution. Tribological characterization is performed under lubricated sliding. Composite surface does not react with the concerned lubricant. Without any change in the amount of solid lubricant (nano-Gr) or TiB2, wear and friction behavior of composites enhanced sufficiently in presence of liquid lubricant at contact surface compared to dry condition.