Please wait a minute...
金属学报  2020, Vol. 56 Issue (5): 736-744    DOI: 10.11900/0412.1961.2019.00293
  本期目录 | 过刊浏览 |
人工时效对2A12铝板力学性能和强化相的影响
梁孟超, 陈良(), 赵国群
山东大学液固结构演变与加工教育部重点实验室 济南 250061
Effects of Artificial Ageing on Mechanical Properties and Precipitation of 2A12 Al Sheet
LIANG Mengchao, CHEN Liang(), ZHAO Guoqun
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061, China
全文: PDF(2909 KB)   HTML
摘要: 

在不同温度和保温时间下对2A12铝合金冷轧板进行了人工时效处理,通过显微硬度和室温拉伸实验测试了合金的力学性能,对不同时效阶段合金的微观组织和析出相进行了表征。研究发现,2A12铝合金冷轧板具有单个时效峰,时效温度越高,达到峰值时效所需的时间越短,时效温度与时间对其力学性能均具有较大影响。随时效时间的增加,合金断裂方式由韧性断裂逐渐转变为沿晶韧窝断裂和穿晶断裂。时效初期合金主要为Cu-Mg团簇强化,峰值时效时为Cu-Mg团簇和GPB区强化,过时效时析出相逐渐转化为稳定的S (Al2CuMg)相。在考虑均质形核与非均质形核的共同作用下,2A12铝合金冷轧板的时效脱溶析出序列为过饱和固溶体(SSS)→Cu-Mg团簇+Sinhomo→Cu-Mg团簇+GPB区+Sinhomo→Cu-Mg团簇+GPB区+Shomo+Sinhomo→S。

关键词 2A12铝合金冷轧板人工时效析出相力学性能    
Abstract

2A12 Al alloy has been widely applied in the fields of aviation, aerospace, and vehicles due to its light weight, high specific strength and good corrosion resistance. The solution and ageing treatments are usually performed after the processing on 2A12 Al alloy, and the ageing parameters greatly affect the final mechanical properties. In the present study, the artificial ageing was performed on the cold rolled 2A12 Al sheet under various holding temperatures and holding time. The mechanical properties were evaluated by micro-hardness and tensile tests. Moreover, the evolution of microstructure and precipitations during ageing with different holding time were characterized. The results showed that the 2A12 Al sheet had the sole peak ageing, and the higher the temperature, the shorter time was required for the peak ageing. Both the holding temperature and holding time significantly affected the mechanical properties. The optimal ageing parameters were determined as holding at 185 ℃ for 16 h, and the corresponding yield strength, ultimate tensile strength and elongation along rolling direction were 381 MPa, 476 MPa and 13.6%, respectively. S (Al2CuMg) phase gradually precipitated during ageing process, and the size and distribution of S phase greatly affected the fracture mechanism. At the initial stage of ageing, S phase precipitated near grain boundaries, and the ductility fracture could be observed. With the extension of holding time, the coarsening of S phase took place, and the fracture was gradually transformed to intergranular and transcrystalline modes. Cu-Mg cluster was the main strengthening mechanism at the initial stage of ageing. Both Cu-Mg cluster and GPB zone contributed to the strengthening under the peak ageing, and the precipitations were transformed to stable S phase under the over ageing. Considering the combined effects of homogeneous and inhomogeneous nucleation, the precipitation during ageing of cold rolled 2A12 Al sheet followed the sequence of supersaturated solid solution (SSS)→Cu-Mg cluster+Sinhomo→Cu-Mg cluster+GPB zone+Sinhomo→Cu-Mg cluster +GPB zone+ Shomo+Sinhomo→S.

Key wordscold rolled 2A12 Al sheet    artificial ageing    precipitate    mechanical property
收稿日期: 2019-09-06     
ZTFLH:  TG156  
基金资助:国家重点研发计划项目(2017YFB0306402);国家自然科学基金项目(51735008)
通讯作者: 陈良     E-mail: chenliang@sdu.edu.cn
Corresponding author: CHEN Liang     E-mail: chenliang@sdu.edu.cn
作者简介: 梁孟超,男,1992年生,硕士

引用本文:

梁孟超, 陈良, 赵国群. 人工时效对2A12铝板力学性能和强化相的影响[J]. 金属学报, 2020, 56(5): 736-744.
Mengchao LIANG, Liang CHEN, Guoqun ZHAO. Effects of Artificial Ageing on Mechanical Properties and Precipitation of 2A12 Al Sheet. Acta Metall Sin, 2020, 56(5): 736-744.

链接本文:

https://www.ams.org.cn/CN/10.11900/0412.1961.2019.00293      或      https://www.ams.org.cn/CN/Y2020/V56/I5/736

No.

Ageing temperature

Ageing time

h

No.

Ageing temperature

Ageing time

h

11554111854
2155101218510
3155161318516
4155241418524
5155361518536
61704162004
7170101720010
8170161820016
9170241920024
10170362020036
表1  人工时效实验方案
图1  拉伸试样形状及尺寸
图2  微观组织观察与拉伸试样取样位置示意图
图3  2A12铝合金冷轧板人工时效过程显微硬度曲线
图4  不同时效温度条件下2A12铝合金冷轧板沿RD方向拉伸性能变化曲线
图5  185 ℃下时效不同时间2A12铝合金冷轧板沿TD方向拉伸性能变化曲线
图6  185 ℃下时效不同时间2A12铝合金冷轧板沿RD方向的拉伸断口形貌
图7  2A12铝合金冷轧板在185 ℃下人工时效4 h后的TEM像及选区电子衍射(SAED)花样
图8  沿[001]Al方向Al基体及S相衍射斑点示意图
图9  2A12铝合金冷轧板在185 ℃下人工时效16 h后的TEM像及SAED花样
图10  2A12铝合金冷轧板在185 ℃下人工时效64 h后显微组织的TEM像
图11  2A12铝合金在185 ℃下人工时效64 h后基体中颗粒状析出相的HRTEM像及SAED花样
1 Chen L, Zhao G Q, Gong J, et al. Hot deformation behaviors and processing maps of 2024 aluminum alloy in as-cast and homogenized states [J]. J. Mater. Eng. Perform., 2015, 24: 5002
2 Liu Z L, Cui H T, Ji S D, et al. Improving joint features and mechanical properties of pinless fiction stir welding of alcald 2A12-T4 aluminum alloy [J]. J. Mater. Sci. Technol., 2016, 32: 1372
3 Zhang Z H, Li W Y, Li J L, et al. Microstructure and anisotropic mechanical behavior of friction stir welded AA2024 alloy sheets [J]. Mater. Charact., 2015, 107: 112
doi: 10.1016/j.matchar.2015.06.039
4 Sha G, Marceau R K W, Gao X, et al. Nanostructure of aluminium alloy 2024: Segregation, clustering and precipitation processes [J]. Acta Mater., 2011, 59: 1659
doi: 10.1016/j.actamat.2010.11.033
5 Bagaryatsky Y A. Structural changes on aging Al-Cu-Mg alloys [J]. Dokl. Akad. Nauk SSSR., 1952, 87: 397
6 Styles M J, Marceau R K W, Bastow T J, et al. The competition between metastable and equilibrium S (Al2CuMg) phase during the decomposition of AlCuMg alloys [J]. Acta Mater., 2015, 98: 64
7 Feng Z Q, Yang Y Q, Huang B, et al. HRTEM and HAADF-STEM tomography investigation of the heterogeneously formed S (Al2CuMg) precipitates in Al-Cu-Mg alloy [J]. Philos. Mag., 2013, 93: 1843
8 Charai A, Walther T, Alfonso C, et al. Coexistence of clusters, GPB zones, S''-, S'- and S-phases in an Al-0.9% Cu-1.4% Mg alloy [J]. Acta Mater., 2000, 48: 2751
9 Sunde J K, Johnstone D N, Wenner S, et al. Crystallographic relationships of T-/S-phase aggregates in an Al-Cu-Mg-Ag alloy [J]. Acta Mater., 2019, 166: 587
10 Wang J, Zhang B, Zhou Y T, et al. Multiple twins of a decagonal approximant embedded in S-Al2CuMg phase resulting in pitting initiation of a 2024Al alloy [J]. Acta Mater., 2015, 82: 22
11 Ringer S P, Hono K, Polmear I J, et al. Nucleation of precipitates in aged Al-Cu-Mg-(Ag) alloys with high Cu∶Mg ratios [J]. Acta Mater., 1996, 44: 1883
doi: 10.1016/1359-6454(95)00314-2
12 Ringer S P, Caraher S K, Polmear I J. Response to comments on cluster hardening in an aged Al-Cu-Mg alloy [J]. Scr. Mater., 1998, 39: 1559
doi: 10.1016/S1359-6462(98)00364-9
13 Wang S C, Starink M J, Gao N. Precipitation hardening in Al-Cu-Mg alloys revisited [J]. Scr. Mater., 2006, 54: 287
doi: 10.1016/j.scriptamat.2005.09.010
14 Wang S C, Starink M J. Two types of S phase precipitates in Al-Cu-Mg alloys [J]. Acta Mater., 2007, 55: 933
doi: 10.1016/j.actamat.2006.09.015
15 Moghanaki S K, Kazeminezhad M. Effects of non-isothermal annealing on microstructure and mechanical properties of severely deformed 2024 aluminum alloy [J]. Trans. Nonferrous Met. Soc. China, 2017, 27: 1
doi: 10.1016/S1003-6326(17)60001-3
16 Moy C K S, Weiss M, Xia J H, et al. Influence of heat treatment on the microstructure, texture and formability of 2024 aluminium alloy [J]. Mater. Sci. Eng., 2012, A552: 48
17 Feng Z Q, Yang Y Q, Huang B, et al. Variant selection and the strengthening effect of S precipitates at dislocations in Al-Cu-Mg alloy [J]. Acta Mater., 2011, 59: 2412
18 Feng Z Q, Yang Y Q, Huang B, et al. STEM-HAADF tomography investigation of grain boundary precipitates in Al-Cu-Mg alloy [J]. Mater. Lett., 2011, 65: 2808
19 Ringer S P, Sakurai T, Polmear I J. Origins of hardening in aged Al-Cu-Mg-(Ag) alloys [J]. Acta Mater., 1997, 45: 3731
doi: 10.1021/es1036332 pmid: 21410193
20 Liu Y, Teng F, Cao F H, et al. Defective GP-zones and their evolution in an Al-Cu-Mg alloy during high-temperature aging [J]. J. Alloys Compd., 2019, 774: 988
21 Tolley A, Ferragut R, Somoza A. Microstructural characterisation of a commercial Al-Cu-Mg alloy combining transmission electron microscopy and positron annihilation spectroscopy [J]. Philos. Mag., 2009, 89: 1095
22 Zuiko I, Kaibyshev R. Aging behavior of an Al-Cu-Mg alloy [J]. J. Alloys Compd., 2018, 759: 108
doi: 10.3390/ma12182907 pmid: 31505758
23 Fu S, Zhang Y, Liu H Q, et al. Influence of electric field on the quenched-in vacancy and solute clustering during early stage ageing of Al-Cu alloy [J]. J. Mater. Sci. Technol., 2018, 34: 335
doi: 10.1016/j.jmst.2017.07.020
24 Li Y, Guo M X, Jiang N, et al. Precipitation behaviors and preparation of an advanced Al-0.93Mg-0.78Si-0.20Cu-3.00Zn alloy for automotive application [J]. Acta Metall. Sin., 2016, 52: 191
doi: 10.11900/0412.1961.2015.00334
24 李 勇, 郭明星, 姜 宁等. 汽车用新型Al-0.93Mg-0.78Si-0.20Cu-3.00Zn合金的制备及其时效析出行为研究 [J]. 金属学报, 2016, 52: 191
doi: 10.11900/0412.1961.2015.00334
25 Lotter F, Petschke D, De Geuser F, et al. In situ natural ageing of Al-Cu-(Mg) alloys: The effect of In and Sn on the very early stages of decomposition [J]. Scr. Mater., 2019, 168: 104
[1] 耿遥祥, 樊世敏, 简江林, 徐澍, 张志杰, 鞠洪博, 喻利花, 许俊华. 选区激光熔化专用AlSiMg合金成分设计及力学性能[J]. 金属学报, 2020, 56(6): 821-830.
[2] 黄远, 杜金龙, 王祖敏. 二元互不固溶金属合金化的研究进展[J]. 金属学报, 2020, 56(6): 801-820.
[3] 李源才, 江五贵, 周宇. 温度对碳纳米管增强纳米蜂窝镍力学性能的影响[J]. 金属学报, 2020, 56(5): 785-794.
[4] 赵燕春, 毛雪晶, 李文生, 孙浩, 李春玲, 赵鹏彪, 寇生中. Fe-15Mn-5Si-14Cr-0.2C非晶钢微观组织与腐蚀行为[J]. 金属学报, 2020, 56(5): 715-722.
[5] 姚小飞, 魏敬鹏, 吕煜坤, 李田野. (CoCrFeMnNi)97.02Mo2.98高熵合金σ相析出演变及力学性能[J]. 金属学报, 2020, 56(5): 769-775.
[6] 杨柯,史显波,严伟,曾云鹏,单以银,任毅. 新型含Cu管线钢——提高管线耐微生物腐蚀性能的新途径[J]. 金属学报, 2020, 56(4): 385-399.
[7] 蒋一,程满浪,姜海洪,周庆龙,姜美雪,江来珠,蒋益明. 高强度含NNi奥氏体不锈钢08Cr19Mn6Ni3Cu2N (QN1803)的显微组织及性能[J]. 金属学报, 2020, 56(4): 642-652.
[8] 刘振宝,梁剑雄,苏杰,王晓辉,孙永庆,王长军,杨志勇. 高强度不锈钢的研究及发展现状[J]. 金属学报, 2020, 56(4): 549-557.
[9] 于雷,罗海文. 部分再结晶退火对无取向硅钢的磁性能与力学性能的影响[J]. 金属学报, 2020, 56(3): 291-300.
[10] 曹育菡,王理林,吴庆峰,何峰,张忠明,王志军. CoCrFeNiMo0.2高熵合金的不完全再结晶组织与力学性能[J]. 金属学报, 2020, 56(3): 333-339.
[11] 周霞,刘霄霞. 石墨烯纳米片增强镁基复合材料力学性能及增强机制[J]. 金属学报, 2020, 56(2): 240-248.
[12] 程超,陈志勇,秦绪山,刘建荣,王清江. TA32钛合金厚板的微观组织、织构与力学性能[J]. 金属学报, 2020, 56(2): 193-202.
[13] 张健,王莉,王栋,谢光,卢玉章,申健,楼琅洪. 镍基单晶高温合金的研发进展[J]. 金属学报, 2019, 55(9): 1077-1094.
[14] 宫声凯, 尚勇, 张继, 郭喜平, 林均品, 赵希宏. 我国典型金属间化合物基高温结构材料的研究进展与应用[J]. 金属学报, 2019, 55(9): 1067-1076.
[15] 陈兴品,李文佳,任平,曹文全,刘庆. C含量对Fe-Mn-Al-C低密度钢组织和性能的影响[J]. 金属学报, 2019, 55(8): 951-957.