Fan-Type Inducer for a Centrifugal Pump with Multi-Material Blades Made of Stellite 6 and SST 316L Additively Fabricated using Wire Arc Additive Manufacturing

The value of applying wire arc additive manufacturing (WAAM) to impellers, a key component of turbomachinery including pumps, has been variously discussed. WAAM is a metal additive manufacturing technology suitable for fabricating medium to large components by applying arc welding. Many of these studies are intended to fabricate components using only a single material. While welding wires for WAAM are commercially available in various materials, enabling the potential for multi-material components, research focused on industrial applications of multi-materialization has been limited. This study conducted experimental investigations aimed at extending the service life of a fan-type inducer. The inducer is an axial flow impeller attached to a centrifugal pump in order to improve pump suction performance. The service life of inducers is affected by cavitation erosion of the blades. Therefore, it is planned to use a multi-material blade combining Stellite 6, which is highly resistant to cavitation erosion, and SST 316L, a general purpose austenitic stainless steel. Two experiments were conducted. The aim of the first experiment was to evaluate mechanical properties using WAAM fabricated multi-material test specimens. The aim of the second experiment was the fabrication of an inducer with a multi-material blade using WAAM and machining. Experimental results of multi-material test specimens confirmed that the mechanical properties are suitable for industrial applications. The inductor was fabricated within industrial-grade dimensional tolerances. These results clarify that multi-material blades combining Stellite 6 and SST 316L are feasible using WAAM.