Impact of Soot and Engine Oil Additive Characteristics on Metallic Wear using Electron Microscopy and Confocal Microscopy

Soot particles are produced inside the combustion chamber of the internal combustion engines and will later be exhausted into the thermosphere. Part of these particles will contaminate the engine oil. When this happens, diesel engine abrasion or, in a worst-case scenario, lubricant starvation will occur. This circumstance will eventually cause engine wear. This research uses X-Ray Fluorescence (XRF) technique to analyze the additive element in engine oil. For wear test, this research uses tribology Four ball wear tester to substitute point contact wear mechanism. Then the worn surface is analyzed with Scanning Electron Microscope (SEM). Confocal Microscope are used to study the effect of additive on soot dispersion in engine oil, which affects the metal wear mechanism. This research use Laser Particle Size Analyzer to investigate performance of soot dispersant additive in each engine oil. The results show that, the wear scar diameters significantly increased when the American Petroleum Institute (API) CD standard engine oil is contaminated with soot. On the other hand, American Petroleum Institute (API) CF-4 standard engine oil which contains higher amount of additive has a lower roughness value, because its soot dispersant additive improves the dispersing of carbon black (CB). When the CB is dispersed, it will serve to polish the ball’s surface, resulting in a lower roughness value in the CB contaminated high amount of additive engine oil, than the low amount of additive engine oil that has soot contaminating.