Effects of Ageing Temperature on Microstructure and Mechanical Properties of 2519 Aluminum Alloy

The microstructure and mechanical properties of 2519 aluminum alloy aged at 135-200 ℃ for different times were investigated by means of microhardness test and tensile test,transmission electron microscope analysis.The results show that aged at 135,150 ℃,2519 aluminum alloy responsed slowly.And aged at 165-200 ℃,three respective stages were observed during the ageing process and they are under-ageing,peak-ageing and over-ageing,respectively.Time of reaching peak-ageing was gradually shortened from 15 h to 6 h with the increase of ageing temperature,and the microhardness of peak-ageing of the alloy gradually decreased from 127 HV to 118 HV with the increase of ageing temperature,respectively.The alloy elongation decreased with the increase of ageing temperature.The optimal ageing temperature of 2519 aluminum alloy is 165 ℃.