Method for manufacturing impeller

摘要

A method for manufacturing an impeller includes providing a disc and a cover separate from the disc, one of the cover and the disc having integrally formed blades and the other one of cover and the disc having a first joint surface, joining the disc and the cover to each other by brazing in a state in which a first brazing filler metal is interposed between the first joint surface and a second joint surface provided on the blades, and during the joining operation, maintaining a space between the first joint surface and the second joint surface by providing a spacer on an outer periphery side of the impeller. The thickness of the spacer is smaller than the thickness of the first brazing filler metal before melting. The spacer is formed integrally with the blade or is formed integrally with said other one of the cover and the disc.