Maskless Electrochemical Texturing of Automotive Cylinders

Abstract

Abstract In internal combustion engines, friction between the rings and the cylinder liner is responsible for considerable energy losses. The surface topography of the contacting surfaces has direct effects on lubrication and friction. Different techniques for surface texturing have been used, such as laser and photochemical texturing. In this work, a recently developed technique is adapted to texture gray cast-iron diesel cylinder liners. This technique, called maskless electrochemical texturing (MECT), features great simplicity, low cost, high speed, and low complexity of the apparatus involved. The tool is cathodic and the workpiece to be textured is anodic under pulsed voltage. The electrolyte passes through perforated microcavities in the tool, resulting in texturing of the workpiece. This work aimed to adapt MECT to texture cylindrical surfaces and to find adequate texturing parameters for gray cast-iron cylinder liners. The process variables investigated in this work and how they affect the depth of features, the amount of overcut, and the anodic dissolution localization were the distance between the tool and workpiece, the voltage, and the texturing time. Patterns containing arrays of chevrons were successfully produced in cylinder liners.