Study on the microstructure and properties of 7050 aluminum alloy made by LFEC

摘要

7050 aluminum alloy F200 mm ingots were made by the low frequency electromagnetic casting (LFEC) process and DC casting process, respectively. Effects of electromagnetic field frequency and current intensity on microstructures were investigated. The results showed that LFEC has significant effects on macrostructure and microstructure refinement, and can improve as-cast mechanical properties. The microstructures of LFEC ingot from the border to the center on the cross section are all fine equiaxed or nearly equiaxed grains which are much finer and more uniform than that of DC cast ingot. It was found that electromagnetic field frequency and current intensity play important roles on the microstructure refinement. In the range of experimental parameters, the optimum current intensity and electromagnetic field frequency for LFEC process is found to be 120 to 160 A and 20 to 25 Hz.