Application of boronizing technique to a diesel engines' combusiton chamber parts

In this study, adiabatic property was brought to a 4-cylinder natural aspirated, direct injection diesel engine. For this purpose, cylinder liner, piston upper surface and valves were coated with powder with boron. Solid-boronizing method and plasma spray method were used as coating method. While cylinder liner and valves were coated with the layer of Fe2B in the thickness of 150 micron by using solid boronizing method, piston upper surface was coated with the layer of CoNiCrAlYttra +NiCrBSi in the thickness of 300 micron by using plasma spray method. After the coating process, the engine was subject to performance and emission tests. As test fuel, peanut oil methyl ester (POME) and pumpkin seed oil methyl ester were produced from peanut oil and pumpkin seed oil by applying alkali catalyzed transesterification method. In uncoated engine, performance, exhaust emission and exhaust gas temperature values were recorded by operating with D-2 (normal diesel fuel) and B-20-50-100 fuels. Then, test fuels were tested again in coated engine. Performance and exhaust emission values were recorded for the second time. Lastly, required evaluations were made by comparing all data obtained from coated and uncoated engines with each other. As a result of tests for the D-2 duel, while BSFC value of coated engine decreased at the rate of 7.5% and BSEC value decreased at the rate of 7%, an increase occurred at the rate of 1.5% in BTE value and at the rate of 15% in EGT value. While a decrease was observed at the rate of 10% in CO value, 47% in HC value, and 14% in Smoke value, an increase was observed at the rate of 35% in NOx value. Finally, coated engine parts were subjected to surface analysis methods. For this pupose, optical microscopy, SEM, XRD, surface roughness, wear test were used for analysis methods. Key words : ,Boronizing, Coating, Engine, Biodiesel, Performance, Emission, Surface