Influence of a low-frequency electromagnetic field on precipitation behavior of a high strength aluminum alloy

The effect of an electromagnetic field on microstructure and hardness of a novel super-strength aluminum alloy was studied. The electromagnetic field accelerates the diffusion process and so the active dissolution of excess phases, which results in high supersaturation of hardening alloy elements in the aluminum matrix upon quenching. As a result, the growth of grains was promoted due to the decreasing of the pinning effect. With application of electromagnetic field the distribution of the hardening alloy elements became homogenous and the grain boundary segregation decrease. The concentration of particles within the matrix is enhanced and a higher value of hardness was obtained after aging due to higher solute concentration within the matrix and more finer and spaced grain boundary precipitates are obtained. A wider precipitate free zone (PFZ) is obtained by the depletion of solutes adjacent to the grain boundary due to formation of grain boundary precipitates.