Al?Zn?Mg?Cu?Zr?(Sc)合金攪拌摩擦焊接頭組織和性能

王宇; 熊柏青; 李志輝; 溫凱; 李錫武; 張永安; 閆麗珍; 劉紅偉; 閆宏偉

doi:10.13374/j.issn2095-9389.2019.05.29.001

Al?Zn?Mg?Cu?Zr?(Sc)合金攪拌摩擦焊接頭組織和性能

doi: 10.13374/j.issn2095-9389.2019.05.29.001

王宇^{1, 2, 3},
熊柏青^{1, 3},
李志輝^{1, 3, ,},
溫凱^{1, 3},
李錫武^{1, 3},
張永安^{1, 3},
閆麗珍^{1, 3},
劉紅偉^{1, 3},
閆宏偉^{1, 3}

1.
有研工程技術研究院有限公司有色金屬材料制備加工國家重點實驗室，北京 101407
2.
有研億金新材料有限公司，北京 102200
3.
有研科技集團有限公司，北京 100088

基金項目: 國家重點研發計劃資助項目（2016YFB0300903，2016YFB0300803）

詳細信息

通訊作者:
E-mail: lzh@grinm.com

中圖分類號: TG146.2
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出版歷程
- 收稿日期: 2019-05-29
- 刊出日期: 2020-05-01

Microstructure and properties of friction stir welded joints for Al?Zn?Mg?Cu?Zr?(Sc) alloys

WANG Yu^{1, 2, 3},
XIONG Bai-qing^{1, 3},
LI Zhi-hui^{1, 3
, ,},
WEN Kai^{1, 3},
LI Xi-wu^{1, 3},
ZHANG Yong-an^{1, 3},
YAN Li-zhen^{1, 3},
LIU Hong-wei^{1, 3},
YAN Hong-wei^{1, 3}

1.
State Key Laboratory of Nonferrous Metals and Processes, GRIMAT Engineering Institute Co., Ltd., Beijing 101407, China
2.
GRIKIN Advanced Materials Co., Ltd., Beijing 102200, China
3.
GRINM Group Co., Ltd., Beijing 100088, China

More Information

Corresponding author: E-mail: lzh@grinm.com

摘要

摘要: 利用光學顯微鏡、透射電子顯微鏡、顯微硬度計和萬能拉伸試驗機等分析手段，表征了Al?Zn?Mg?Cu?Zr?(Sc)合金攪拌摩擦焊（FSW）接頭的顯微組織和性能，探究了Sc元素對改善超高強Al?Zn?Mg?Cu?Zr合金焊接性能的作用機制。結果表明：Al?Zn?Mg?Cu?Zr?(Sc)合金焊接接頭具有相似的組織特征，焊核區為動態再結晶組織，由細小均勻的等軸晶組成，包含較高密度的位錯線，大部分時效析出相回溶；熱力影響區晶粒被拉長，位錯密度更高，殘留的時效析出相顯著粗化；熱影響區保留與母材相同的晶粒形態，大部分時效析出的η'相發生長大，少部分粗化成η相。添加質量分數0.17%的Sc，可以使合金FSW接頭抗拉強度提升43 MPa，屈服強度提升23 MPa，斷后伸長率改善2.3%，焊接系數達到74.1%。Al₃(Sc,Zr)二次析出相可以強烈抑制位錯、亞晶界、晶界的移動，細化晶粒的同時保留大量的亞結構，且自身可發揮Orowan彌散強化作用。因此，可通過細晶強化、亞結構強化和彌散強化三種方式顯著提高合金FSW接頭的力學性能。
- Al?Zn?Mg?Cu?Zr?(Sc)合金 /
- Al₃(Sc,Zr) /
- FSW接頭 /
- 顯微組織 /
- 力學性能
Abstract: Addition of Sc is capable of greatly improving the mechanical properties of aluminum alloy welded joints, reducing the hot crack sensitivity coefficient; thus, it could solve the welding problem of ultra-high strength aluminum alloys. Friction stir welding has the advantages of small heat-affected zone, low residual stress, and small deformation of welding work piece, making it a good choice for welding materials with high heat crack sensitivity. In this article, the microstructure and properties of friction stir welding (FSW) joints of Al–Zn–Mg–Cu–Zr–(Sc) alloys were characterized via optical microscopy (OM), transmission electron microscopy (TEM), micro-hardness testing, and universal tensile testing. The mechanism of the effect of adding Sc element on improving the welding properties of the ultra-high strength Al–Zn–Mg–Cu–Zr alloy was explored. The results show that the welding joints of Al–Zn–Mg–Cu–Zr–(Sc) alloy exhibit similar microstructure characteristics. The welding nugget zone (WNZ) displays a dynamic recrystallization feature comprising fine and uniform equiaxed grains with high density dislocations. Most of the aged precipitates dissolve into the matrix in the WNZ. The grains in the thermal-mechanical affected zone (TMAZ) are elongated with higher dislocation density, and residual aged precipitates coarsened remarkably. The heat-affected zone (HAZ) retains the same grain morphology as the base metal. Most of the aged η' precipitates grow, and a few coarsen to be the η phase in this zone. However, 0.17% (mass fraction) Sc addition increases the ultimate tensile strength of FSW joint by 43 MPa, yield strength by 23 MPa, elongation by 2.3%, and the welding coefficient up to 74.1%. Al₃(Sc, Zr) dispersoids are found to achieve the following: 1) strongly inhibit the movement of dislocations, sub-grain boundaries, and grain boundaries; 2) significantly refine grains while retaining several sub-structures; and 3) factor in Orowan precipitation strengthening. Therefore, the mechanical properties of FSW joints can be improved using the refined grain, sub-structure, and precipitation strengthening mechanisms.
- Al?Zn?Mg?Cu?Zr?Sc alloy /
- Al₃(Sc, Zr) /
- FSW joint /
- microstructure /
- mechanical property

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圖 1 拉伸力學性能測試取樣示意圖（a）和試樣尺寸示意圖（b）

Figure 1. Schematic diagram (a) of the specimen sampling from the weld plates and dimensional schematics (b) of the tensile specimens tested in this work

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圖 2 Al?Zn?Mg?Cu?Zr?(Sc)合金母材的選區電子衍射花樣。（a, b） 1#合金；（c, d） 2#合金

Figure 2. SAED patterns of base material for Al?Zn?Mg?Cu?Zr?(Sc) alloys: (a, b) Alloy 1#; (c, d) Alloy 2#

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圖 3 Al?Zn?Mg?Cu?Zr?(Sc)合金母材的晶內和晶界析出相。（a, b） 1#合金；（c, d） 2#合金

Figure 3. Precipitates distributed in the grain and along the boundary of the base material for Al?Zn?Mg?Cu?Zr?(Sc) alloys: (a, b) Alloy 1#; (c, d) Alloy 2#

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圖 4 2#合金FSW接頭。（a）橫截面形貌；（b）區域劃分

Figure 4. FSW joints for Alloy 2: (a) cross-sectional appearances; (b) divided zones

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圖 5 1#和 2#合金FSW接頭的金相顯微組織。（a, b） WNZ；（c, d） TMAZ；（e, f） HAZ；其中，1#合金（a, c, e），2#合金（b, d, f）

Figure 5. Optical microstructure of the FSW joints for Alloy 1 and Alloy 2: (a, b) WNZ; (c, d) TMAZ; (e, f) HAZ; among them, Alloy 1# (a, c, e) and Alloy 2# (b, d, f)

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圖 6 1#和2#合金FSW接頭位錯觀察。（a, b） WNZ；（c, d） TMAZ；（e, f） HAZ；其中，1#合金（a, c, e），2#合金（b, d, f）

Figure 6. Dislocations observation of the FSW joints for Alloy 1 and Alloy 2: (a, b) WNZ, (c, d) TMAZ, (e, f) HAZ; among them, Alloy 1# (a, c, e) and Alloy 2# (b, d, f)

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圖 7 1#和2#合金FSW接頭的選區電子衍射花樣和析出相形貌。（a, b） WNZ；（c, d） TMAZ；（e, f） HAZ；其中，1#合金（a, c, e），2#合金（b, d, f）

Figure 7. SAED patterns and precipitates of the FSW joints for Alloy 1 and Alloy 2: (a, b) WNZ, (c, d) TMAZ, (e, f) HAZ; among them, Alloy 1# (a, c, e) and Alloy 2# (b, d, f)

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圖 8 研究合金的FSW接頭顯微硬度分布圖

Figure 8. Micro-hardness profile of the FSW joints for the investigated alloys

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圖 9 2#合金FSW接頭處的Al₃（Sc,Zr）形貌。（a） BM；（b） WNZ

Figure 9. Morphologies of Al₃(Sc,Zr) particles of the FSW joint for Alloy 2: (a) BM; (b) WNZ

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表 1 合金的化學成分及編號

Table 1. Chemical composition and designation for the tested alloys

Number	Classification	Composition (mass fraction) / %
Number	Classification	Zn	Mg	Cu	Zr	Sc	Si	Fe	Al
1#	Nominal	9.2	2.2	1.5	0.11	0	≤0.08	≤0.10	Bal.
1#	Measured	9.42	2.33	1.62	0.12	0
2#	Nominal	9.2	2.2	1.5	0.11	0.17
2#	Measured	9.84	2.26	1.58	0.12	0.17

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表 2 研究合金的母材和FSW接頭拉伸力學性能

Table 2. Tensile properties of the base material and the FSW joint for the investigated alloys

Number	Ultimate tensile strength/MPa	Yield strength/MPa	Elongation/%	Welding coefficient/%	Fracture site
1#-Base material	613±8	557±11	8.3±2.1	—	—
1#-Weld joint	439±4	352±2	2.0±0.3	71.6	WNZ
2#-Base material	651±2	601±7	7.3±2.9	—	—
2#-Weld joint	482±3	375±6	4.3±0.4	74.1	WNZ

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參考文獻(24)

[1]	Sharma N, Khan Z A, Siddiquee A N. Friction stir welding of aluminum to copper-an overview. Trans Nonferrous Met Soc China, 2017, 27(10): 2113 doi: 10.1016/S1003-6326(17)60238-3
[2]	Cam G, Mistikoglu S. Recent developments in friction stir welding of Al-alloys. J Mater Eng Perform, 2014, 23(6): 1936 doi: 10.1007/s11665-014-0968-x
[3]	Janaki Ram G D, Mitra T K, Shankar V, et al. Microstructural refinement through inoculation of type 7020 Al?Zn?Mg alloy welds and its effect on hot cracking and tensile properties. J Mater Process Technol, 2003, 142(1): 174 doi: 10.1016/S0924-0136(03)00574-0
[4]	Seshagiri P C, Nair B S, Reddy G M, et al. Improvement of mechanical properties of aluminum-copper alloy (AA2219) GTA welds by Sc addition. Sci Technol Weld Join, 2008, 13(2): 146 doi: 10.1179/174329308X283866
[5]	Tong J H, Li L, Deng D, et al. Friction stir welding of 6061-T6 aluminum alloy thin sheets. J Univ Sci Technol Beijing, 2008, 30(9): 1011 doi: 10.3321/j.issn:1001-053X.2008.09.010 佟建華, 李煉, 鄧冬, 等. 6061-T6鋁合金薄板的攪拌摩擦焊接. 北京科技大學學報, 2008, 30(9):1011 doi: 10.3321/j.issn:1001-053X.2008.09.010
[6]	Zhang K, Jiang H T, Meng Q, et al. Effect of the welding speed on the microstructure and the mechanical properties of robotic friction stir welded AA7B04 aluminum alloy. Chin J Eng, 2018, 40(12): 1525 張坤, 江海濤, 孟強, 等. 焊接速度對機器人攪拌摩擦焊AA7B04鋁合金接頭組織和力學性能的影響. 工程科學學報, 2018, 40(12):1525
[7]	Norman A F, Hyde K, Costello F, et al. Examination of the effect of Sc on 2000 and 7000 series aluminium alloy castings: for improvements in fusion welding. Mater Sci Eng A, 2003, 354(1-2): 188 doi: 10.1016/S0921-5093(02)00942-5
[8]	Chen Y, Liu C Y, Zhang B, et al. Effects of friction stir processing and minor Sc addition on the microstructure, mechanical properties, and damping capacity of 7055 Al alloy. Mater Charact, 2018, 135: 25 doi: 10.1016/j.matchar.2017.11.030
[9]	Zhao Z H, Xu Z, Wang G S. Effect of Sc, Zr, Er in ER5356 welding wire on mechanical properties of welded joint of 7A52 aluminum alloy. Chin J Mater Res, 2013, 27(3): 287 趙志浩, 徐振, 王高松. ER5356焊絲中Sc、Zr、Er對7A52鋁合金焊接性能的影響. 材料研究學報, 2013, 27(3):287
[10]	Yuan H X. Study on Effect of Welding Materials and Procedures on Weldability of Aluminum Alloys[Dissertation]. Chongqing: Chongqing University, 2006 元恒新. 焊接材料及工藝對鋁合金焊接性能的影響[學位論文]. 重慶: 重慶大學, 2006
[11]	He Z B, Peng Y Y, Yin Z M, et al. Comparison of FSW and TIG welded joints in Al?Mg?Mn?Sc?Zr alloy plates. Trans Nonferrous Metal Soc China, 2011, 21(8): 1685 doi: 10.1016/S1003-6326(11)60915-1
[12]	Mishra R S, Ma Z Y. Friction stir welding and processing. Mater Sci Eng R, 2005, 50(1-2): 1 doi: 10.1016/j.mser.2005.07.001
[13]	Wang Y, Xiong B Q, Li Z H, et al. Hot compressive deformation behavior and microstructure characterization of new ultra strength Al?Zn?Mg?Cu alloy. J Mater Eng, 2019, 47(2): 99 doi: 10.11868/j.issn.1001-4381.2018.000699 王宇, 熊柏青, 李志輝, 等. 新型超高強Al?Zn?Mg?Cu合金熱壓縮變形行為及微觀組織特征. 材料工程, 2019, 47(2):99 doi: 10.11868/j.issn.1001-4381.2018.000699
[14]	Sha G, Cerezo A. Early-stage precipitation in Al?Zn?Mg?Cu alloy (7050). Acta Mater, 2004, 52(15): 4503 doi: 10.1016/j.actamat.2004.06.025
[15]	Li X Z, Hansen V, Gj?nnes J, et al. HREM study and structure modeling of the η' phase, the hardening precipitates in commercial Al?Zn?Mg alloys. Acta Mater, 1999, 47(9): 2651 doi: 10.1016/S1359-6454(99)00138-X
[16]	Habiby F, Haq A U, Hashmi F H, et al. Some remarks on the hardness and yield strength of aluminum alloy 7075 as a function of retrogression time. Metall Mater Trans A, 1987, 18(2): 350 doi: 10.1007/BF02825718
[17]	Benavides S, Li Y, Murr L E, et al. Low-temperature friction-stir welding of 2024 aluminum. Scripta Mater, 1999, 41(8): 809 doi: 10.1016/S1359-6462(99)00226-2
[18]	Sato Y S, Kokawa H, Enomoto M, et al. Microstructural evolution of 6063 aluminum during friction-stir welding. Metall Mater Trans A, 1999, 30(9): 2429 doi: 10.1007/s11661-999-0251-1
[19]	Mahoney M W, Rhodes C G, Flintoff J G, et al. Properties of friction-stir-welded 7075 T651 aluminum. Metall Mater Trans A, 1998, 29A: 1955
[20]	Wang Y, Xiong B Q, Li Z H, et al. As-cast microstructure of Al?Zn?Mg?Cu?Zr alloy containing trace amount of Sc. Rare Met, 2019, 38(4): 343 doi: 10.1007/s12598-018-1136-5
[21]	Su J Q, Nelson T W, Mishra R, et al. Microstructural investigation of friction stir welded 7050-T651 aluminum. Acta Mater, 2003, 51(3): 713 doi: 10.1016/S1359-6454(02)00449-4
[22]	Adler P N, Delasi R. Calorimetric studies of 7000 series aluminum alloys: II. Comparison of 7075, 7050 and RX720 alloys. Metall Trans A, 1977, 8(7): 1185 doi: 10.1007/BF02667404
[23]	Li Z M. Study on the Microstructure and Properties of Al−Zn−Mg Alloy with Scandium Addition[Dissertation]. Beijing: University of Chinese Academic Science, 2018 李召明. Sc對Al−Zn−Mg合金組織和性能影響的研究[學位論文]. 北京: 中國科學院大學, 2018
[24]	Deng Y, Peng B, Xu G F, et al. Effects of Sc and Zr on mechanical property and microstructure of tungsten inert gas and friction stir welded aerospace high strength Al?Zn?Mg alloys. Mater Sci Eng A, 2015, 639: 500 doi: 10.1016/j.msea.2015.05.052