The Influence of Lead Suspension in Oil Lubricant on the Sliding Wear Behaviour of Cast Iron

Abstract

This investigation pertains to the analysis of the sliding wear response of a cast iron over a range of applied pressures in the presence of an oil lubricant. The effect of varying concentrations of lead particles suspended in the oil lubricant on the wear behaviour of the cast iron was also examined. The wear rate increased with pressure initially at a lower rate followed by a higher rate of increase beyond a specific pressure. Furthermore, the presence of suspended lead particles up to a specific concentration in the oil proved beneficial while the trend reversed at still higher concentrations. The extent of frictional heating increased with test duration at a high rate in the beginning of the tests. This was followed by a reduced rate of temperature increase at longer test durations. In some cases, the rate of temperature rise increased once again while it reduced in one case towards the end of the tests. The severity and extent of frictional heating also increased with pressure.

Sliding wear characteristics of grey cast iron as affected by the type and fraction of solid lubricants in oil

“…Further, the exposure and smearing of graphite and other solid lubricating phases on the wear surfaces ( Figure 12(c) and 13(b and d)) as well as flow of graphite in the sliding direction below the wear surface ( Figure 14, regions marked by B) suggest the lubrication effect produced by the solid lubricant particles dispersed in the oil and within the sample material to take part in controlling the wear behaviour. The solid lubricant film so formed and sticking debris on the wear surfaces reduce the extent of direct metal-to-metal contact and brings about improved wear response (Prasad, 2005(Prasad, , 2007b(Prasad, , 2009aPrasad et al, 2010bPrasad et al, , 20112010a, 2010cPrasad, 2010;Prasad (in press) ;Prasad, 2009b;Prasad and Modi, 2008). Plastic deformation on and below the wear surface ( Figure 12-14), sticking of debris on the wear surface ( Figure 13(a), region marked by A) and the presence of flakes in the debris (Figure 15, region marked by A) suggest adhesion to contribute to material loss.…”

“…Studies have shown that parameters like the content, nature, structure, mode of incorporation, etc. greatly influence the performance of solid lubricants (Boehringer, 1992;Bhushan and Gupta, 1991;Metals Handbook, 1992c;Kumar, 1994;Jha et al, 1986;Bhushan, 2001;Prasad, 2007a;Winer, 1967;Prasad, 2005Prasad, , 2007bPrasad, , 2009aPrasad et al, 2010bPrasad et al, , 2011Prasad et al, , 2010a. One of the ways to realize the benefit of solid lubricants is to suspend them in the base lubricant (oil) and direct the lubricant mixture at the sliding surfaces.…”

“…The lubricating film formed on the wear surfaces also becomes dry and unstable. A few studies (Prasad, 2007a(Prasad, , 2005(Prasad, , 2007b(Prasad, , 2009aPrasad et al, 2010b;2011, 2010a, 2010cPrasad, 2010;Prasad (in press), 2009b;Prasad and Modi, 2008) have shown the optimum solid lubricant content in the oil to be approximately 5 per cent that leads to the best wear performance, while no information seems to be there on the influence of simultaneously adding more than one type of solid lubricants to the oil towards controlling the wear performance.…”