Influence of pre-deformation on microstructure and mechanical properties along thickness direction of 2519A Al alloy thick plate

Abstract

2519A aluminum (Al) alloy is widely employed in the military industry due to its superior strength and anti-ballistic capabilities. However, its inferior mechanical properties along the thickness direction (normal direction of the alloy, ND direction) limit its further utilization in armored vehicles. To enhance the mechanical properties along ND direction of 2519A Al alloy, the microstructure and mechanical properties in ND direction of the alloy at 7–15 % pre-deformation were investigated. The result indicated that the average aspect ratio of the grains (ARGs) of the alloy gradually increased with the increase of pre-deformation, the degree of fragmentation of the coarsen secondary phase gradually increased, and the size and number density of θ′ phase first increased and then decreased. The strength and elongation of the alloy along ND direction were increased firstly and then decreased with the increase of pre-deformation. Especially, the elongation of the alloy decreases by 55 % at 15 % pre-deformation compared to 11 % pre-deformation. The elongation of the alloy is mainly affected by the ARGs and the spacing of the secondary phase. The best mechanical properties along ND direction were obtained at 11 % pre-deformation with yield strength and tensile strength of 448 MPa and 505 MPa, and elongation of 5.99 %, respectively.