Abstract: The metal 3D printing process has the advantages of high material utilization rate, easy to form complex structure and flexible customized production, etc. It is suitable for rapid manufacture of model-level test impellers, guide vanes, inducers and other small metal functional parts. Among them, the selective laser melting forming technology(SLM), as the main metal 3D printing technology, can obtain metallurgical bonding, tissue compactness, high dimensional accuracy and good mechanical properties. The SLM technology was used to directly form the impeller and vane of the main pump test prototype for a project. The material is 17-4PH stainless steel. The integrated printing of the impeller and the assembled shaft saves the assembly cost. The studies on printing model optimization, processing parameters and process monitoring ensure the successful printing of the tall integrated shaft impeller and guide vane with large diameter. The printing parts were heat treated and finish machining, and finally the gas-liquid two-phase performance test of the main pump prototype was carried out. The test results show that the rotating and stator components manufactured by SLM metal 3D printing technology is successfully applied in the prototype test of the main pump, which significantly shortens the processing cycle of the prototype, and the machining accuracy, surface quality and mechanical properties all meet the test requirements.

Key words: metal 3D printing, 17-4PH, integrated printing, application research