THERMAL SPRAY PRETREATMENT OF CYLINDER BLOCK AND THERMAL SPRAY METHOD

摘要

PROBLEM TO BE SOLVED: To provide a thermal spray pretreatment method for forming a thermally sprayed film having an excellent adhesion property by filling the cavities existing on the bore inside surface of a cylinder block and also provide a thermal spray method therefor. SOLUTION: This thermal spray method for the cylinder block includes a step of melting the surface layer part of the bore inside surface 1a of the cylinder block made of an aluminum ally formed which contains silicon in its content components and is formed with the cavities on the surface layer of its bore inside surface by discharging a vacuum arc 5 toward the bore inside surface 1a, a step of sealing the cavities by allowing the molten metal to flow into the cavities, a step of forming a cured layer dispersed with silicon particles below 5μm in diameter in the surface layer part of the bore inside surface 1a and a step of forming the thermally sprayed film by subjecting the cured layer to a thermal spray treatment from above the layer.