Effects of Alternating Magnetic Field on the Hot Tearing Susceptibility and Microstructure of Al-5Cu Alloy

Abstract

The influence of alternating magnetic field on hot tearing susceptibility (HTS) and microstructure of Al-5Cu alloy were studied using hot tearing test system and differential thermal analysis test. The Clyne-Davies model was used to evaluate the HTS of the alloy quantitatively under different magnetic current intensities (0A, 5A, 10A, 15A). The experimental results show that the HTS and microstructure of Al-5Cu alloy can be affected by imposing the alternating magnetic field during alloy solidification. In the range of 0–10A, with the increase of alternating magnetic field current intensity, there is strong forced convection in the molten metallic pool under the action of electromagnetic force, which leads to the fragmentation of dendrites and the grains refinement, optimizes the feeding channels between grains and reduces the HTS of the alloy. When the alternating magnetic field intensity is 15A, the grains become coarser due to the thermal effect of electromagnetic field, resulting in the deterioration of the feeding channel and the increase of HTS.