Search Results

It is well known that machine lifetime, reliability and performance are strongly related to wear. The wear of cylinder bores can increase blow-by, oil consumption, power losses and emissions. Moreover, it can produce axial wear scratches that can harm hydrodynamic support of piston rings, increasing wear even further. The comprehension of the main factors responsible for wear in cylinder bores is, therefore, indispensable for the increase of the efficiency of engines. Despite the great work reported in literature regarding to the analysis of wear in engine cylinders, the study of the types of oxides and tribofilms formed in the surface of the cylinders remains poor. Therefore, the present work aims to correlate wear of cylinder bores from flex-fuel vehicles with engine operating conditions.

Engineered surfaces with dimples working under lubricated regime are a wide open field of research, with many technological applications, especially for automotive industry. The tribological system under these conditions, lubricated dimpled surface, has been investigated and some publication regarding the understating of the phenomena that occur are already known. Dimpled surfaces for system working without lubrication, with wear occurring under dry conditions, are a new approach for friction and wear reduction. This paper investigates dimple textured surfaces operating without lubrication. Dimples with semi spherical geometry with 100 μm of diameter and 25 μm deep were applied on surfaces of hard metal P-20. The dimples distributions over the surfaces were 50 % of the projected area of the counter body. Pin-on-Disc experiments were performed in order to provide data information over friction and wear.