Effect of Mn on Microstructures and Mechanical Properties of 2519 Aluminum Alloy

The effect of Mn on the microstructures and mechanical properties of 2519 aluminum alloy was investigated by means of microhardness test,tensile test,transmission electron microscope and scanning electron microscope.The results show when the content of Mn is less than 0.29wt%,the strength of 2519 aluminum alloy increases with the increase of Mn content;when the content of Mn is greater than 0.29wt%,the strength of 2519 aluminum alloy decreases.The hardening effect of the aged alloy is accelerated at 170℃ and the time to peak-aged is reduced,but the plasticity of the alloy gradually decreases with the increases of Mn content.However,the hardening effect of the aged alloy decreases with the increases of Mn as the content of Mn is over 0.29wt%.The optimal content of Mn of 2519 aluminum alloy is 0.29wt%,at which the alloy has best tesile strength and plasticity.