Abstract: A method of repairing an inner surface of a cylinder liner housed in an engine block. Material is removed from the inner surface to produce a reduced-thickness region, the reduced-thickness region extending axially relative to the cylinder and stopping short of an end of the liner to leave a region of original diameter between the reduced thickness region and the end of the liner. The surface the reduced-thickness region is then roughened, for example by hammer brushing. A plasma coating is applied to the reduced-thickness region and to at least a portion of the region of original diameter. The coating is then finish-machined to produce a uniform internal diameter equal to an original internal diameter of the region of original diameter prior to the application of the coating.

Abstract: A block for an internal combustion engine having at least one coated cylinder bore, which has a chamfer at a sealing surface with respect to a cylinder head, wherein the chamfer is a curved chamfer.

Abstract: A method for preparing a surface, previously roughed in a mechanical manner and comprising sharp-edged ridges and recesses, on metal workpieces for applying a thermally sprayed layer. The roughened layer is machined by hammer or percussion brushes with a rapidly rotating hammer or percussion brush having a plurality of resilient percussion wires that are oriented in a radially outward manner, such that the edges of the ridges are broken in order to improve the adhesion of the subsequently applied thermally sprayed layer or are at least curved forming rear sections. The brush rotates at a high rotational speed of approximately 3000-6000 rotations per minute and is displaced laterally with its rotational axis being at a parallel distance that remains constant in relation to the surface of the workpiece such that percussion wires distributed on the periphery of the brush impact with the ends thereof of the surface areas adjacent to the workpiece at an oblique angle that is less than 90° in rapid succession.

Abstract: A method for preparing a surface, previously roughed in a mechanical manner and comprising sharp-edged ridges and recesses, on metal workpieces for applying a thermally sprayed layer. The roughened layer is machined by hammer or percussion brushes with a rapidly rotating hammer or percussion brush having a plurality of resilient percussion wires that are oriented in a radially outward manner, such that the edges of the ridges are broken in order to improve the adhesion of the subsequently applied thermally sprayed layer or are at least curved forming rear sections. The brush rotates at a high rotational speed of approximately 3000-6000 rotations per minute and is displaced laterally with its rotational axis being at a parallel distance that remains constant in relation to the surface of the workpiece such that percussion wires distributed on the periphery of the brush impact with the ends thereof of the surface areas adjacent to the workpiece at an oblique angle that is less than 90° in rapid succession.