Abstract: A cylinder block of an internal combustion engine has several cylinder bores. The surfaces surrounding the cylinder bores have wear-resistant coatings which closely reproduce the surfaces. The coatings are formed by Plasma Vacuum Deposition.

Abstract: The invention relates to a method for the production of core preforms for foundry in which a) a mixture of inorganic, refractory foundry sand and a water glass-based inorganic binder is produced, b) the mixture is poured into a heated core box c) the water contained in the mixture is withdrawn by a physical method and d) the core preform is taken out of the core box. The process is characterized by the fact that e) the heated core box is subjected to a depression during filling f) the temperature/dwell time is adjusted after the closing of the core box so that a dimensionally stable and good bearing shell is formed on the edge of the preform g) the preform is immediately removed after opening of the core box and, under the effect of microwaves, is subjected to a complete drying.

Abstract: A process and device for the laser treatment of the internal surfaces of hollow bodies such as engine blocks with cylinder bores which consist of the matrix alloys such as a light-metal or aluminum, wherein a wear-resistant coating is applied to the working surfaces of the pistons within the cylinder. A probe enters the cylinder and includes the laser beam which produces a beam spot on the internal surface of the cylinder and applies an alloying powder at the focus of the spot using a continuously conveying protective gas. The probe is displaced along the axis of the cylinder and simultaneously rotated while the alloying powder is melted in the spot of the laser beam to a depth sufficient to form a wear-resistant coating which will not break loose during the normal operation and life of the engine block. The engine block can be fixed in a stationary position while the probe or probes move simultaneously within the cylinders to apply the hardened surface coating.

Abstract: A method for treating a casting having a casting surface by vapor-depositing a wear-resistant coating on to the casting surface.