Low Cost Debris Collection Method to Diagnose Wear in a Combustion Engine

摘要

A challenge of the maintenance engineering is to detect future failures and the wear in machine components without interrupting its operation. Doing it in a cheap and simple way is even more challenging. With this purpose, the present study collected the debris expelled in the exhaust pipe of an engine through an innovative device built in the Tribology Study Group of UFRN. It was tested a 5 HP stationary diesel engine working under constant load over 150 hours (non-continuous). The morphology and chemicals compounds of the debris collected by the device were analyzed using Scanning Electrons Microscope (SEM) and Energy Dispersive Spectroscopy (EDS), respectively. After the 150 hours of testing, the engine was disassembled and visually inspected. Photos were taken to identify the wear mechanisms present on the piston skirt, piston head, cylinder head and valves. After that, was made a correlation between the collected debris and the wear mechanisms observed in the piston. The common shapes of the debris were: chunk and platelet, indicating the presence of fatigue and abrasion wear in their formation. The chemical microanalysis of the debris showed elements such as aluminum, silicon and iron, suggesting that those particles came from the piston, what is confirmed by the wear mechanisms on the piston, such as spalling, abrasion and tribocorrosion, observed in the visual inspection. The method of debris collection showed us that it is possible to evaluate some of the wear mechanisms of an engine with a lower cost than other usual debris analysis and without stopping the engine.