Large-sized 2219 aluminum alloy ingot has wide application prospect in aerospace and military fields. Severe defects, such as coarse grain, the inhomogeneity of structure and macrosegregation occurred in large-sized aluminum ingot produced by normal DC casting. The application of a single magnetic field in DC casting process cannot solve these defects. In this paper, a new method with the combination of electromagnetic fields imposed on bulk melt treatment during DC casting was proposed. And a φ508 mm ingot of 2219 aluminum alloy was prepared in this method. Compared with the normal DC casting, the effect of the combined electromagnetic fields on the microstructure and properties was studied. The experimental results demonstrate that the application of the combined electromagnetic fields significantly refines the grains, and the grain size distribution on the cross section of the ingot tends to be more uniform as well as the mechanical properties are significantly improved. The microstructure and grain size distribution can be significantly affected by different combined electromagnetic fields. It is considered that the appropriate combined electromagnetic fields parameters play an important role in controlling the homogeneity of large-sized ingots.
Influence of Filler Wire Feed Speed on Microstructure and Properties of MIG Welding of 7005 Aluminum Alloy
