Numerical Simulation Based On Software Fluent Of 3-D Flow Field Of Deep Penetration In Electron Beam Welding For Aluminum Alloy

The key of quality control is the flow shape of welding pool in electron beam welding. It is difficult to choose and calculate the characteristic area which can indicate the welding quality. FLUENT was used to build flow models of welding pool and reactive metal-vapor in keyhole of deep penetration in EBW based on the effect of the keyhole. The characteristic area on top of the keyhole was studied and it was used to forecast the seam quality and supervise the technology. The flow field of reactive metal-vapor and welding pool were researched. And it is significant in theory for further research on deep penetration in EBW, process of keyhole formation and quality control of penetration.2-D standard models with different depth such as 5mm,8mm,10mm,13mm and 15mm were built and the the flow fields of temperature were similar. The temperature in middle of the keyhole was higher than that in other areas. But different keyhole frofiles were getted from models with different depth. The metal-vapor width was determined to attribute the seam formation. 3-D model of reactive metal-vapor with the chamber was built. It showed that the characteristic area was nummular in different depths and the metal-vapor width was extended according to the seam depth. The law was further researched as the technologic instruction for aluiminum alloy welding.3-D model of pool flow field was built to further analyse the effect of the keyhole on the seam formation. It displayed that the pool flow field was divised to different area apparently with the agitation of the keyhole in both horizontal and vertical directions. And the flow field was prolonged as"V"with high velocity near the keyhole in horizontal direction. But it was at low velocity far away from the keyhole because of the weak effect. There were visible flow fields in vertical direction. Molten-liquid flowed mussily in the liquid center and the molten-liquid floated as laminar both on the surface and bottom of welding pool. The flow field formation of wekding pool was investigated to represent the relationship among the effect of the keyhole and seam formation.