Metal flow observation by multi-dimensional innovated X-ray image technology

Abstract

This paper presents the relationship between the fluid vortexes in the melted domain and the key-hole diameter in plasma arc welding (PAW). The application of 4-Dimensional innovated X-ray image technology for material flow observations. The advanced PAW experiment was conducted with the use of different orifice diameters. It was found that there are two fluid vortexes (a vortex pair) in the melted domain in PAW. When the keyhole boundary changes, there is a big change of the relative contour of each vortex due to the orifice diameter variation. Each vortex's relative profiles are dependent on the mass transfer and convection flow in the melted domain. An enormous vortex is created at the lower part of the weld pool. When the orifice diameter increases, the plasma arc column is expanded, and the vortex at the top side of the weld pool is much bigger and longer. The findings can be used to develop simulation algorithms for the PAW and Additive Manufacturing process, especially for the development of intelligent manufacturing processes based on metal welding and fused deposition principles.