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本文通过对三种二元铝-锂合金在不同热处理条件下的组织结构观察和力学性能实验,研究了其第二相沉淀特征和微观组织与性能的关系。结果表明,525℃固溶1h是这些合金最佳固溶条件。190℃25h是峰值时效条件,此时弥散强化和有序强化作用均最大;相同时间160℃时效为欠时效条件,析出相颗粒较小,强(硬)度较低,220℃25h过时效处理,δ′相粗大,合金变形时位错绕过δ′相,因此,此时无有序强化作用,强(硬)度下降。
In this paper, through the observation of microstructures and mechanical properties of three kinds of binary aluminum-lithium alloys under different heat treatment conditions, the relationship between the second phase precipitation and the microstructure and properties was studied. The results show that solid solution at 525 ℃ for 1h is the best solution for these alloys. 190 ℃ 25h is the peak aging conditions, this time the maximum dispersion and strengthening the role of the order; the same time aging at 160 ℃ under-aging conditions, precipitated phase particles smaller, less (strong), 220 ℃ 25h over-aging , the δ ’phase is coarse, and dislocations around the δ’ phase are deformed when the alloy is deformed. Therefore, there is no orderly strengthening action at this time, and the degree of strong (hard) decreases.