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通过显微组织观察、硬度测试以及XRD分析,研究强化固溶处理对一种Sr微合金化2099型铝锂合金组织和位错强化的影响。结果表明,与常规固溶(540℃,2h)相比,强化固溶(540℃,2h+550℃,2.67h)促进了合金中粗大第二相的溶解,降低了合金后续T8时效处理(121℃,14h+151℃,48h)后的硬度(分别为162.7HV和154.1HV),显著降低了合金中的位错及位错强化。基于Taylor公式的定量计算表明,强化固溶使合金时效强化有所加强,强化固溶合金硬度的降低主要是位错强化降低所致。微合金化元素Sr不能有效使2099型铝锂合金在其固溶处理温度(540～550℃)驻留位错,2099型铝锂合金强度、硬度的进一步提高需要进行进一步微合金化设计。
The effects of strengthening solution treatment on the microstructure and dislocation strengthening of Sr-based microalloyed 2099 Al-Li alloy were investigated by microstructure observation, hardness test and XRD analysis. The results show that solid solution strengthening (540 ℃, 2h + 550 ℃, 2.67h) promotes the dissolution of the coarse second phase in the alloy compared with the conventional solid solution (540 ℃, 2h), and reduces the alloy’s subsequent T8 aging treatment 121 ℃, 14h + 151 ℃, 48h), the hardness (162.7HV and 154.1HV respectively) significantly reduced the dislocation and dislocation strengthening in the alloy. Quantitative calculation based on the Taylor formula shows that the strengthening solution treatment strengthens the aging strengthening of the alloy and the decrease of the hardness of the strengthening solid solution alloy is mainly due to the decrease of dislocation strengthening. Microalloying element Sr can not effectively make dislocation dislocations of 2099 Al-Li alloy at its solution treatment temperature (540-550 ℃). The further improvement of the strength and hardness of 2099 Al-Li alloy requires the further microalloying design.