微量Sr对Al-Mg-Si-Cu基合金的时效析出过程及动力学的影响

EFFECTS OF MINOR STRONTIUM ADDITION ON AGEING PRECIPITATION PROCESS AND KINETICS OF Al-Mg-Si-Cu BASED ALLOYS

采用差热扫描量(differentialscanningcalorimeter,DSC)分析Sr含量对Al Mg Si Cu基合金时效β″和Q相激活能的影响。结果表明,加入Sr不改变β″和Q相的析出温度,但能影响它们的激活能。当Sr含量较低(0.033%,质量百分数)时,时效相的激活能较低,比较容易析出,使合金得到更好强化;当Sr含量较高(0.093%)时,时效相的激活能较大,从而较难析出,对合金的强化作用较弱。

The activation energies of ageing phases β＂ and Q of Al-Mg-Si-Cu based alloys with different content of Sr were investi- gated by differential scanning calorimeter （DSC）. The results show that the addition of Sr into Al-Mg-Si-Cu based alloys can not change the precipitating temperature of the ageing phases, but can change the activation energies of the precipitations of β″ and Q. In compafison with Al-Mg-Si-Cu based alloy with 0.093% Sr, the activation energies of β″ and Q in Al-Mg-Si-Cu based alloy with 0.033% sr are low, so they precipitate easily and strengthen the alloy inteasely.