Precipitation kinetics of 2519A aluminum alloy based on aging curves and DSC analysis
(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Bichamp Cutting Technology (Hunan) Co., Ltd., Changsha 410200, China;
3. Parametric Technology Corporation, Shanghai 200120, China)
2. Bichamp Cutting Technology (Hunan) Co., Ltd., Changsha 410200, China;
3. Parametric Technology Corporation, Shanghai 200120, China)
Abstract: The precipitation kinetics of 2519A aluminum alloy after different cold rolling reductions before aging was investigated by hardness test and differential scanning calorimetry (DSC). The activation energy was calculated according to DSC curves using single heating rate method. The microstructures of as-rolled and peak-aged alloys were observed by transmission electron microscopy (TEM). The result shows that the age hardenability reduces and the activation energy rises with increasing the reduction from 7% to 40%. Nonuniform dislocations are found in as-rolled alloy and inhomogeneous distribution of θ′ phase is revealed in peak-aged alloy when the reduction is 15%. The inhomogeneous distribution of θ′ phase may be related to the age hardenability reducing and activation energy rising.
Key words: 2519A aluminum alloy; dislocation structure; precipitation kinetics; θ′ phase; differential scanning calorimetry (DSC)