用SAXS研究锂对7000系铝合金相变动力学的影响

 为了深入了解锂对7000系铝合金的影响，以获得优良性能含锂超高强铝合金，对含锂7000系铝合金进行了研究。采用小角X射线散射（SAXS）实验方法对7000系及含锂的7000系铝合金进行相变动力学研究，得出了析出相颗粒尺寸和体积分数。根据获得的这些数据进一步确定成核、长大和相变3个阶段的激活能。结果表明：含锂合金的析出相长大和粗化进程比无锂合金更加缓慢；含锂合金的成核激活能小于无锂合金，长大激活能和相变激活能都大于无锂合金，说明含锂合金析出相成核容易，长大和整个相变过程都比无锂合金困难。

Influence of Lithium on the Kinetics of Phase Transformation in 7000 Series Aluminum Alloy by SAXS Investigation

To understand deeply the influence of lithium on 7000 series aluminum alloys,to obtain the Li-containing high strength alloys with good performance,the 7000 series Li-containing alloys are studied.The phase transformation kinetietics of the 7000 series Li-containing alloys containing lithium is investigated in comparison with Li-free 7000 series alloys by small angel X-ray scattering(SAXS) experimental measurements.The parameters for precipitate mean size and volume fraction are obtained by SAXS theory,and the activation energy for three stages is further obtained on the basis of the above information,including nucleus,growing and coarsening.The results show that as compared with Li-free alloys,the precipitation process of growing and coarsening is slower and nucleus activation energy is smaller,but the activation energy of growing and coarsening is larger in Li-containing alloys.It suggests that nucleus formation is easier,but the precipitation coruse of growing and coarsening is more difficult in Li-containing alloys than in Li-free alloys.