Simulation of wear characteristics of engine cylinders

This present work shows that a pin-on-disc (POD) tester is able to simulate the wear conditions occurring in real, marine diesel engines. This is promising, because a simple POD apparatus thus can be used to select new candidate materials for marine diesel engines, before more expensive and realistic tests are conducted. This early selection of materials will be based on relative measurements of new materials and existing materials with known properties. In its present form, the method is not based on quantitative measurements. In addition, the present work intends to clarify the mechanisms leading to the wear phenomena known as smearing and scuffing in two-stroke marine diesel engines. The tribo-system of the pin and disc is examined extensively, using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Vickers hardness indentation. Based on these findings an empirical model of smearing and scuffing has been established. This four-stage model is well supported by previous experimental [Wear 100 (1984) 315; Proc. Inst. Mech. Eng. 185 (1971/1972) 21; Wear 236 (1999) 199; Wear 236 (1999) 210] and theoretical [Wear 236 (1999) 199; Wear 236 (1999) 210; Wear 212 (1997) 213] work based on the wedge model of friction. By applying the empirical simulation data in the materials selection process, better materials for cylinders may be expected in the future.