Evaluation of Wire Arc Additive Manufacturing for Cavitation Erosion-Damaged Blade Repairs

Wire arc additive manufacturing (WAAM) is an additive manufacturing technology that is suitable for large parts and parts with complex shapes such as blades. The area is the topic of research and development for industrial applications. Various studies have revealed the industrial advantages of applying WAAM to part manufacturing compared to traditional fabrication methods. In this study, to further clarify the advantages of industrial applications of WAAM, a study on the repair of impellers that have been damaged by cavitation erosion using WAAM was conducted on turbopumps used in a wide range of industries. A fan-type inducer used in industrial centrifugal pumps was used as a test model. The fan-type inducer was installed in a centrifugal pump experimental apparatus, and then, paint erosion tests were conducted. This test was used to investigate the area of damage to the blades that was caused by cavitation erosion. The results show that the area damaged by cavitation erosion is the trailing edge of the suction tip side of the blade. Based on the paint erosion tests, the machining time for repairing blades with a hybrid system of WAAM and machining were calculated and compared with those required to fabricate a new part. The conclusion was reached that the application of WAAM to the fabrication process of industrial turbopumps has advantages not only in the manufacture of parts, but also in the repair of the parts.