高位错密度对Al-Cu-Li合金板材蠕变时效响应和力学性能的影响

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中文摘要：由于传统处理工艺下Al-Cu-Li合金的蠕变应变非常低，导致Al-Cu-Li合金壁板构件蠕变时效成形的难度大幅度增加。因此，提高Al-Cu-Li合金蠕变成形性是一个亟需解决的问题。本文详细地研究了低温下施加大预变形(LPD)和室温下施加大预变形对2195 Al-Cu-Li合金板材蠕变时效响应的影响。利用X射线衍射和透射电子显微镜揭示了LPD 合金蠕变时效过程中的位错和析出相的演变规律。通过在液氮温度下进行轧制，获得了具有80%预变形且无边缘开裂的高质量2195合金板材。然而，板材在室温轧制过程中出现了严重的边缘开裂。此外，通过引入高位错密度(位错密度在1。4×1015 m-2以上)，2195 Al-Cu-Li合金的蠕变成形性和时效后的强度得到了协同提升。与传统的T3态合金相比，在160℃和150 MPa下，LPD 合金的蠕变应变和时效后的强度分别提高了4～6倍和30～50 MPa，但是伸长率有所降低。LPD合金中位错多以位错缠结的组态存在，但是促进了细小T1相均匀析出。

外文标题：High density dislocations enhance creep ageing response and mechanical properties in 2195 alloy sheet

外文摘要：The creep strain of conventionally treated 2195 alloy is very low,increasing the difficulty of manufacturing Al-Cu-Li alloy sheet parts by creep age forming.Therefore,finding a solution to improve the creep formability of Al-Cu-Li alloy is vital.A thorough comparison of the effects of cryo-deformation and ambient temperature large pre-deformation(LPD)on the creep ageing response in the 2195 alloy sheet at 160℃with different stresses has been made.The evolution of dislocations and precipitates during creep ageing of LPD alloys are revealed by X-ray diffraction and transmission electron microscopy.High-quality 2195 alloy sheet largely pre-deformed by 80%without edge-cracking is obtained by cryo-rolling at liquid nitrogen temperature,while severe edge-cracking occurs during room temperature rolling.The creep formability and strength of the 2195 alloy are both enhanced by introducing pre-existing dislocations with a density over 1.4×1015 m-2.At 160℃and 150 MPa,creep strain and creep-aged strength generally increases by 4-6 times and 30-50 MPa in the LPD sample,respectively,compared to conventional T3 alloy counterpart.The elongation of creep-aged LPD sample is low but remains relevant for application.The high-density dislocations,though existing in the form of dislocation tangles,promote the formation of refined T1 precipitates with a uniform dispersion.

外文关键词：

creep ageingAl-Cu-Li alloyhigh dislocation densitycryogenic rollingdislocation strengthening

作者：

魏硕、马培培、陈龙辉、杨建使、湛利华、刘春辉

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作者单位：

Light Alloy Research Institute,Central South University,Changsha 410083,China

State Key Laboratory of Precision Manufacturing for Extreme Service Performance,Central South University,Changsha 410083,China

School of Mechanical and Electrical Engineering,Central South University,Changsha 410083,China

Advancd Research Center,Central South University,Changsha 410083,China Light Alloy Research

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关键词：

蠕变时效 Al-Cu-Li合金高位错密度低温轧制位错强化

基金：

National Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNatural Science Foundation of Hunan Province,ChinaNatural Science Foundation of Hunan Province,ChinaScience and Technology Innovation Program of Hunan Province,ChinaFundamental Research Funds for the Central Universities,ChinaNational Key R&D Program of China

项目编号：

5227440452305441U22A201902022JJ200652023JJ407392022RC10012023ZZTS09722021YFB3400903

出版年：

2024

DOI：

10.1007/s11771-024-5684-6

中南大学学报(英文版)

中南大学

中南大学学报(英文版)

CSTPCDEI

影响因子：0.47

ISSN：2095-2899

年,卷(期)：2024.31(7)