The experimental investigation of wear behaviour of a diesel engine with cylinder having ceramic coated surface

ABSTRACT PhD Thesis THE EXPERIMENTAL INVESTIGATION OF WEAR BEHAVIOUR OF A DIESEL ENGINE WITH CYLINDER HAVING CERAMIC COATED SURFACE Hanbey HAZAR Fırat University Graduate School of Natural and Applied Sciences Department of Machine Education 2004, Page : 110 In this study, wear behaviours of cylinder surface coated with CrN of a diesel engine were investigated. The engine selected for evaluation was a four-stroke, direct-injection, one cylinder diesel engine which the surface of the engine's cylinder was coated with 1.8 ± 0,2 um thickness of ceramic materials (CrN) using the katodik Ark PVD (Physical Vapour Deposition) technique. First, tiie ceramic coated test engine was tested 200 hours at different speed and load conditions. Then, this teste engine was tested again under the same operation conditions as the standart engine without a coating. The test data for both engine's performance were compared as diagrams. Samples the coated and uncoated cylinder surfaces were cut of same part for examine of wear effects. Phases present in the coated and uncoated surfaces and their chemical compositions were analyzed by SEM (Scanning Electron Microscopy), EDS (Energy Dispersive Spectrograph), X-Ray diffraction, surface roughness and micro-hardness. In addition, the specific fuel consumption, effective power, the engine moment, exhaust and oil temperature and exhaust emissions to coated and uncoated engines have been measured. Comparing the CrN coated cylinder with the uncoated cylinder, the poor wear and the worn depth observed on samples. The surfaces of wear specimens were observed by an SEM. XIIMicrostructual analysis of the CrN coated surfaces showed that micro-craks were formed on the coated surfaces, which considered as a result of the a reaction during coating process. The micro-hardness and corrosion resistance of CrN coated cylinder is higher compared with gray cast iron cylinder, moreover the friction coffecient and surface roughness of CrN coated cylinder is smaller than gray cast iron cylinder. That affects wear resistance. The coating (1.8 ±0,2 um) thickness of ceramic materials (CrN) of the surface of the engine's cylinder is less significant to engine performance. In the case of coated engine, exhaust gas temperatures incresaed addition of insulation. The experimental results show that, the ceramic coated engine affects CO emission parameter. Keywords : Ceramic coating, CrN, cylinder, wear. XIII