Lubricated Tribology of a Eutectic Aluminium-Silicon Alloy in the Ultra-Mild Wear and Mild Wear Regimes for Long Sliding Times

Mahato, Anirban and Sachdev, Anil and Biswas, SK (2010) Lubricated Tribology of a Eutectic Aluminium-Silicon Alloy in the Ultra-Mild Wear and Mild Wear Regimes for Long Sliding Times. In: ACS Applied materials & interfaces , 2 (10). pp. 2870-2879.

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Abstract

Aluminium-silicon alloy, an important material used for the construction of internal combustion engines, exhibit pressure induced distinct regimes of wear and friction; ultra-mild and mild. In this work the alloy is slid lubricated against a spherical steel pin at contact pressures characteristic of the two test regimes, at a very low sliding velocity. In both cases, the friction is controlled at the initial stages of sliding by the abrasion of the steel pin by the protruding silicon particles of the disc. The generation of nascent steel chips helps to breakdown the additive in the oil by a cationic exchange that yields chemical products of benefits to the tribology. The friction is initially controlled by abrasion, but the chemical products gain increasing importance in controlling friction with sliding time. After long times, depending on contact pressure, the chemical products determine sliding friction exclusively. In this paper, a host of mechanical and spectroscopic techniques are used to identify and characterize mechanical damage and chemical changes. Although the basic dissipation mechanisms are the same in the two regimes, the matrix remains practically unworn in the low-pressure ultra-mild wear regime. In the higher pressure regime at long sliding times a small but finite wear rate prevails. Incipient plasticity in the subsurface controls the mechanism of wear.

Item Type:	Journal Article
Publication:	ACS Applied materials & interfaces
Publisher:	American chemical society
Additional Information:	Copyright of this article belongs to American chemical society.
Keywords:	aluminium-silicon alloy; ultra-mild wear; mild wear; tribofilm; time-dependent transition
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	19 Nov 2010 11:13
Last Modified:	24 Jan 2011 06:52
URI:	http://eprints.iisc.ac.in/id/eprint/33853

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