Surface and Wear Analysis of Zinc Phosphate Coated Engine Oil Ring and Cylinder Liner Tested with Commercial Lubricant

Abstract

The objective of this study was to evaluate the tribological performance through investigating protective additive layer and friction coefficient and implementing the quantitative wear measurements on the rubbed surface of the sliding pairs. The specimens of oil ring were rubbed against cast iron engine cylinder liner under boundary lubrication conditions. The ring and liner surfaces were examined by optical, scanning electron microscope and atomic force microscopy. The elemental analysis of surfaces was performed by using energy dispersive X-ray spectroscopy. Surface observations showed that coating was removed from the ring surface. Higher levels of Ca, Zn, P, and S elemental ratios (0.93%, 0.45%, 1.55%, and 1.60% as atomic percent) were detected on the cylinder liner surface. Wear width, length, and depth measurements were performed by optical and atomic force microscopies on the ring and cylinder liner surface. The results showed that wear widths for oil ring were 1.59 m and 1.65 m; wear widths for cylinder liner were 3.20 m and 3.18 m; wear depths for oil ring were 100 nm; and wear depths for cylinder liner were 482 nm. Wear data were taken mostly from the additive layer points detected by SEM and X-ray measurements.

Comparison of tribological performances of sulfur based and boron succuminide containing antiwear additive with ZDDP by engine bench tests

“…Volume 68 • Number 4 • 2016 • 482-496 These sides did not rub with the cylinder liner surface directly but they rubbed with the piston ring groove. Zinc phosphate coating has low coating thickness and hardness and can remove from the surface in the reciprocating motion, as Doguş et al (2014) indicated in their study. It is known that boron is a light element and it is hard to detect boron with EDX analysis; for this reason, boron was not detected on the NP-3 oil-lubricated surfaces.…”

Surface and wear mechanisms analysis of phosphorous-free and conventional engine lubricants on cylinder liner and piston rings surfaces

“…In addition, only wear transfer elements (Cr, Si and Mn) were detected on the oil ring surface, lubricated with NPNA, as can be seen in X-ray spectra of Figure 7(d). The detected calcium content on the oil ring surface was from the zinc phosphate coating of piston ring due to modification with calcium to get higher wear corrosion resistance (Özkan and Kaleli, 2014).…”

A review on preparation process and tribological performance of coatings for internal combustion engine piston ring

“…Iron phosphate, zinc phosphate and manganese phosphate are three common phosphate coatings. In order to obtain the wear trend of zinc phosphate coating, Özkan and Kaleli 57 conducted tests between zinc phosphate piston ring (Honda GH-200 engine) and gray cast iron cylinder liner (Honda GX-390 engine) on a reciprocating tribotester under boundary lubricating conditions. It was found that the proportion of calcium, zinc and phosphorus in the piston ring decreased and transferred to the cylinder liner surface.…”