Chromium plated cylinder bores for internal combustion engine - with microcrazed surface polished after heat treatment or mechanical treatment

摘要

A Cr plated surface is improved by subjecting a hard flat chromium-plated surface to a thermal treatment at 100-300 degrees C for several hours to develop or alter a microcrack pattern, followed by subjecting the microcracked surface to an abrasive polishing process. Used for polishing internal combustion engine cylinder linings. The lubrication properties of the linings are improved since oil can adhere to a roughened surface with depressions better than to a flat surface. The surface can be roughened with a more regular pattern than by simple grinding. Instead of heat-treating, tre microcracking can be produced mechanically by a grinding process. Both mechanical and heat microcracking can be used in combination.