摘要
The pronounced anisotropy in mechanical properties presents a major obstacle to the extensive application of aluminum-lithium(Al-Li)alloys,primarily attributed to heterogeneous precipitate distribution,grain structure variations,and crystallographic texture.This study investigates the impact of pre-thermal treatment prior to hot rolling and aging treatment on the anisotropy of mechanical properties of 2195 alloy sheet fabricated by gas atomization,hot pressing and hot rolling.The results demonstrate that pre-treatment at 450℃for 4 h promotes finer and more uniform distribution of precipitates,effectively mitigating mechanical anisotropy of the alloy sheet.Additionally,this treatment facilitates recrystallization during hot rolling,further reducing mechanical anisotropy.The in-plane anisotropy(IPA)factors for ultimate tensile strength(UTS)and yield strength(YS)are 1.15%and 0.77%,respectively.Subsequent aging treatment enhances grain refinement and the uniformity of the T_(1) phase,suppresses the formation of precipitation-free zones(PFZs),significantly improving the strength and toughness of the alloy sheet.After peak aging at 165℃for 48 h,the alloy sheet exhibits YS of 547 MPa,UTS of 590 MPa,and elongation(EL)of 7.7%.
由于第二相分布、晶粒结构以及晶体织构的差异,铝锂合金力学性能各向异性十分显著,严重阻碍了其广范应用。本研究探讨了轧前预热处理对气雾化、热压和热轧制备的2195合金板材力学性能各向异性的影响。结果表明,在450/4 h的预热处理工艺可以使得析出相分布得更加细小和均匀,从而有效缓解了合金板材的力学性能各向异性。此外,该预热处理工艺有利于在热轧过程中发生再结晶,进一步降低了其各向异性。预热处理后抗拉强度(UTS)和延伸率(EL)的各向异性(IPA)系数分别为1.15%和0.77%。随后的时效处理增强了T_(1)相的均匀性,抑制了无沉淀带(PFZ)的形成,显著提高了合金板材的强度和韧性。在165℃进行48 h峰值时效处理后,合金的YS、UTS和EL分别达到547 MPa、590 MPa和7.7%。
基金
Project(52274369)supported by the National Natural Science Foundation of China
Project(623020034)supported by the National Key Laboratory of Science and Technology on High-strength Structural Materials,China。
作者简介
Corresponding author:WANG Ri-chu,E-mail:rcwcsu@163.com,ORCID:https://orcid.org/0000-0001-7522-8884;Corresponding author:CAI Zhi-yong,E-mail:zycaimse@163.com,ORCID:https://orcid.org/0000-0002-4926-8441。
