Effects of Solution Treatment in Electric Field on Second Phase and Mechanical Properties of 2219 Aluminum Alloy

The presence of a large number of coarse second-phase (Al₂Cu) particles in 2219 aluminum alloy is an important factor contributing to its low strength and toughness.The effects of the new process of electric field solution treatment on the second phase and mechanical properties of 2219 aluminum alloy were studied by means of SEM, TEM and tensile tests.The results show that applying an electric field of 12 kV/cm during the solid solution treatment can improve the short-range diffusion rate of copper elements, and promote the dissolution of coarse second phase.Compared with the unapplied electric field, the content of the coarse second phase in the alloy is reduced by the electric field solution treatment.The dissolution of the coarse second phase increases the content of copper in the aluminum matrix.Furthermore, the precipitation driving force of the alloy dispersion phase increases during the subsequent aging process.The θ' phase is smaller and denser after aging.After the electric field solution treatment, the comprehensive mechanical properties of the alloy improve.The elongation of the alloy increases significantly from 13.3%to 15.6%.