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摘要: 為了研究熱軋鋁/鎂復合板結合強度的變化規律，本文綜合考慮壓下率、軋制溫度和軋制速度等多種軋制參數，單道次熱軋制備了7075 Al/AZ31B Mg復合板。結果表明：在復合板軋制過程中由于熱和強變形作用組織發生了動態再結晶，且增大軋制速度有助于鎂基體產生完全動態再結晶。在相同軋制溫度下，鋁鎂復合板結合強度均隨壓下率增加先升高后降低；強度升高是由于界面元素擴散寬度的增大和鎂合金近界面晶粒組織的細化所致，強度降低是由于大變形導致鎂基體近界面處產生裂縫，以及塑性功產生熱量過多使得鎂基體溫度升高導致的鎂側晶粒長大所致。對復合板進行拉剪實驗，鋁鎂結合界面剪切強度較低時，斷裂發生在復合界面處且成脆性斷裂特征，強度較高時斷口形貌呈韌性斷裂特征，斷裂發生在鎂基體側。Abstract: Magnesium/aluminum (Mg/Al) bimetallic laminated composites have attracted considerable attention because of their excellent properties. Mg alloys are lightweight structural metals with low density and excellent properties such as high stiffness-to-weight ratio, high strength-to-weight ratio, and good damping capacity. Thus, Mg alloys have considerable potential in automotive and aerospace fields. However, the application of Mg and its alloys is still restricted because of their low corrosion resistance. By contrast, as structural materials, Al alloys are widely used in mechanical and aerospace fields because of their excellent properties, such as light weight, high corrosion resistance, low cost, and good plastic formability. Therefore, Mg/Al laminated composites that combine the advantages of substrates to achieve appropriate coordination, have attracted worldwide attention. To analyze the variation of the bonding strength of hot-rolled Al/Mg clad sheets, various rolling parameters, such as reduction ratio, rolling temperature, and rolling speed, were comprehensively considered in this work. Moreover, 7075 Al/AZ31B Mg composite plates were prepared by single-pass hot rolling. Results show that dynamic recrystallization occurs in the microstructure of the Mg matrix during the rolling process because of heat and strong deformation. Furthermore, the increase in the rolling speed contributed to the complete dynamic recrystallization. At the same rolling temperature, the bonding strength of the Al/Mg composite plates first increased and then decreased with the increase in the reduction ratio. The bonding strength increased because of the increase in the element diffusion width across the interface and the grain refinement near the Mg interface. The bonding strength decreased because cracks occurred near the interface of the Mg matrix due to the strong deformation and excess heat generated by the plastic work, resulting in the growth of the Mg side grains with the increase in the temperature of the Mg matrix. The shear test was conducted on the composite plates. When the shear strength of the Al/Mg composite plates was low, shear fracture occurred at the interface with brittle fracture feature. Although the fracture morphology presented a ductile fracture feature with high shear strength, the fracture occurred on the Mg alloy side.
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Key words:
- 7075 aluminum alloy /
- AZ31B magnesium alloy /
- hot rolling /
- bond strength /
- microstructure
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圖 2 不同軋制速度下復合板鎂基體金相組織（350 ℃，壓下率45%）。 （a） 50 mm·s?1；（b） 100 mm·s?1；（c） 150 mm·s?1
Figure 2. Metallographic structure of the Mg composite matrix under different rolling speeds (350 ℃, 45% reduction rate): (a) 50 mm·s?1; (b) 100 mm·s?1; (c) 150 mm·s?1
圖 3 不同工藝下7075/AZ31B復合板的結合強度
Figure 3. Bonding strength of the 7075/AZ31B clad sheet under different processes
圖 4 不同工藝下復合板的鎂側金相組織。（a） 350 ℃+40%壓下率；（b） 350 ℃ +62%壓下率；（c） 350 ℃ + 70%壓下率；（d） 370 ℃ +40%壓下率；（e） 370 ℃ +63%壓下率；（f） 420 ℃ +61%壓下率
Figure 4. Metallographic structure of the Mg alloy side of the composite board under different processes: (a) 350 ℃ + 40% reduction rate; (b) 350 ℃ + 62% reduction rate; (c) 350 ℃ + 70% reduction rate; (d) 370 ℃ + 40% reduction rate; (e) 370 ℃ + 63% reduction rate; (f) 420 ℃ + 61% reduction rate
圖 5 在350 ℃、62%壓下率下復合板界面的元素線掃描曲線圖
Figure 5. Elemental line scanning curve of the composite plate interface at 350 ℃ with 62% reduction rate
圖 6 350 ℃復合板在不同壓下率下的擴散層寬度
Figure 6. Diffusion layer width of the composite plate at 350 ℃ with the different reduction rates
圖 7 復合板在350 ℃不同壓下率下的結合界面。（a） 62%；（b） 70%
Figure 7. Bonding interface of the composite plate at 350 ℃ under different reduction rates: (a) 62%; (b) 70%
圖 8 350 ℃不同壓下率下斷口的掃描電鏡圖像。（a） 40%/7075側；（b） 40%/AZ31B側；（c） 62%/7075側；（d） 62%/AZ31B側；（e） 70%/7075側；（f） 70%/AZ31B側
Figure 8. SEM image of the fracture at 350 ℃ under different reduction rates: (a) 40%/7075 side; (b) 40%/AZ31B side; (c) 62%/7075 side; (d) 62%/AZ31B side; (e) 70%/7075 side; (f) 70%/AZ31B side
圖 9 復合板350 ℃不同壓下率下7075側斷口的面掃描圖。（a） 40%；（b） 62%；（c） 70%
Figure 9. EDS mapping images of the 7075 side for composite plates at 350 ℃ under different reduction rates: (a) 40%; (b) 62%; (c) 70%
表 1 鋁合金7075和鎂合金AZ31B的化學成分（質量分數）
Table 1. Chemical composition of Al alloy 7075 sheet and Mg alloy AZ31B sheet
% Materials Fe Cu Ti Cr Zn Si Mn Mg Al Ca Zn Be 7075-T6 0.5 1.6 0.2 0.23 5.6 0.4 0.3 2.5 Bal. — — — AZ31B — — — — — 0.03 0.335 Bal. 3.1 0.05 0.82 0.1 
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表 2 元素點掃描測定Al和Mg的元素含量（質量分數）
Table 2. Contents of Al and Mg determined by elemental point scanning
% Element Point 1 Point 2 Point 3 Point 4 Point 5 Point 6 Al 91.2 78.2 2.3 4.7 66.5 39.9 Mg 8.8 21.8 97.7 95.3 33.5 60.1
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參考文獻
[1] Dai J, Huang J, Li Z G, et al. Effects of heat input on microstructure and mechanical properties of laser-welded Mg-rare earth alloy. J Mater Eng Perform, 2013, 22(1): 64 doi: 10.1007/s11665-012-0173-8 [2] Chen Z H. Deformed Magnesium Alloy. Beijing: Chemical Industry Press, 2005陳振華. 變形鎂合金. 北京: 化學工業出版社, 2005 [3] Kojima Y, Kamado S. Fundamental magnesium researches in Japan. Mater Sci Forum, 2005, 488-489: 9 doi: 10.4028/www.scientific.net/MSF.488-489.9 [4] Baghni I M, Wu Y S, Li J Q, et al. Mechanical properties and potential applications of magnesium alloys. Trans Nonferrous Met Soc China, 2003, 13(6): 1253 [5] Schl?gl C M, Planitzer C, Harrer O, et al. Production and formability of roll bounded magnesium (AZ31)-aluminium (1050)-composites. BHM-Berg und Huttenmannische Monatshefte, 2011, 156(7): 249 doi: 10.1007/s00501-011-0003-6 [6] Ikpi M E, Dong J H, Ke W. Effect of cadmium addition on the galvanic corrosion of AM60 magnesium alloy in 0.1 M sodium chloride solution. Solid State Phenomena, 2015, 227: 71 doi: 10.4028/www.scientific.net/SSP.227.71 [7] Fang D Q, Ma N, Cai K L, et al. Age hardening behaviors, mechanical and corrosion properties of deformed Mg–Mn–Sn sheets by pre-rolled treatment. Mater Des, 2014, 54: 72 doi: 10.1016/j.matdes.2013.08.028 [8] Hütsch L L, Hütsch J, Herzberg K, et al. Increased room temperature formability of Mg AZ31 by high speed friction stir processing. Mater Des, 2014, 54: 980 doi: 10.1016/j.matdes.2013.08.108 [9] Zhang T, Shao Y W, Meng G Z, et al. Corrosion of hot extrusion AZ91 magnesium alloy: I-relation between the microstructure and corrosion behavior. Corros Sci, 2011, 53(5): 1960 doi: 10.1016/j.corsci.2011.02.015 [10] Yan Y B, Zhang Z W, Shen W, et al. Microstructure and properties of magnesium AZ31B–aluminum 7075 explosively welded composite plate. Mater Sci Eng A, 2010, 527(9): 2241 doi: 10.1016/j.msea.2009.12.007 [11] Zhang T T, Wang W X, Zhou J, et al. Molecular dynamics simulations and experimental investigations of atomic diffusion behavior at bonding interface in an explosively welded Al/Mg alloy composite plate. Acta Metall Sinica (English Lett) , 2017, 30(10): 983 doi: 10.1007/s40195-017-0628-x [12] Zhang J, Chi C Z, Cui X L, et al. Microstructure and mechanical properties of 5052/AZ31B/5052 three-layer composite sheet prepared by hot pressing. Forging Stamping Technol, 2018, 43(12): 136張晶, 池成忠, 崔曉磊, 等. 熱壓制備5052/AZ31B/5052三層復合板材的微觀組織與力學性能. 鍛壓技術, 2018, 43(12):136 [13] Jafarian M, Rizi M S, Jafarian M, et al. Effect of thermal tempering on microstructure and mechanical properties of Mg-AZ31/Al-6061 diffusion bonding. Mater Sci Eng A, 2016, 666: 372 doi: 10.1016/j.msea.2016.04.011 [14] Luo C Z, Liang W, Li X R, et al. Study on interface characteristics of Al/Mg/Al composite plates fabricated by two-pass hot rolling. Mater Sci Forum, 2013, 747: 346 [15] Zhang J J. Preparation of Al/Mg/Al Laminated Composite Fabricated by Hot Rolled and Investigation of Microstructure and Mechanical Properties[Dissertation]. Taiyuan: Taiyuan University of Technology, 2016張建軍. Al/Mg/Al熱軋復合板的制備及其微觀組織和力學性能研究[學位論文]. 太原: 太原理工大學, 2016 [16] Zhang X P, Tan M J, Yang T H, et al. Bonding strength of Al/Mg/Al alloy tri-metallic laminates fabricated by hot rolling. Bull Mater Sci, 2011, 34(4): 805 doi: 10.1007/s12034-011-0198-x [17] Zhang X P, Yang T H, Liu J Q, et al. Mechanical properties of an Al/Mg/Al trilaminated composite fabricated by hot rolling. J Mater Sci, 2010, 45(13): 3457 doi: 10.1007/s10853-010-4373-z [18] Chen Z J, Zeng Z, Huang G J, et al. Research on the Al/Mg/Al three-layer clad sheet fabricated by hot roll bonding technology. Rare Met Mater Eng, 2011, 40(Suppl 3): 136 [19] Liu C Y, Wang Q, Jia Y Z, et al. Microstructures and mechanical properties of Mg/Mg and Mg/Al/Mg laminated composites prepared via warm roll bonding. Mater Sci Eng A, 2012, 556: 1 doi: 10.1016/j.msea.2012.06.046 [20] Yang X Y, Zhang Z L, Zhang L, et al. Influence of strain rate on dynamic recrystallization behavior of AZ61 magnesium alloy. Trans Nonferrous Met Soc China, 2011, 21(8): 1801 doi: 10.1016/S1003-6326(11)60934-5楊續躍, 張之嶺, 張雷, 等. 應變速率對AZ61鎂合金動態再結晶行為的影響. 中國有色金屬學報, 2011, 21(8):1801 doi: 10.1016/S1003-6326(11)60934-5 [21] Maksoud I A, Ahmed H, R?del J. Investigation of the effect of strain rate and temperature on the deformability and microstructure evolution of AZ31 magnesium alloy. Mater Sci Eng A, 2009, 504(1-2): 40 doi: 10.1016/j.msea.2008.10.033 [22] Santosh R, Das S K, Das G, et al. Three-dimensional thermomechanical simulation and experimental validation on failure of dissimilar material welds. Metall Mater Trans A, 2016, 47(7): 3511 doi: 10.1007/s11661-016-3476-9 [23] Duan X J, Sheppard T. Simulation and control of microstructure evolution during hot extrusion of hard aluminium alloys. Mater Sci Eng A, 2003, 351(1-2): 282 doi: 10.1016/S0921-5093(02)00840-7 [24] Sauvage X, Dinda G P, Wilde G. Non-equilibrium intermixing and phase transformation in severely deformed Al/Ni multilayers. Scripta Mater, 2007, 56(3): 181 doi: 10.1016/j.scriptamat.2006.10.021 [25] Chung C Y, Zhu M, Man C H. Effect of mechanical alloying on the solid state reaction processing of Ni-36.5 at.% Al alloy. Intermetallics, 2002, 10(9): 865 doi: 10.1016/S0966-9795(02)00088-2 [26] Valiev R Z, Islamgaliev R K, Alexandrov I V. Bulk nanostructured materials from severe plastic deformation. Progr Mater Sci, 2000, 45(2): 103 doi: 10.1016/S0079-6425(99)00007-9 [27] Sauvage X, Wetscher F, Pareige P. Mechanical alloying of Cu and Fe induced by severe plastic deformation of a Cu–Fe composite. Acta Mater, 2005, 53(7): 2127 doi: 10.1016/j.actamat.2005.01.024 [28] Sato K, Yoshiie T, Satoh Y, et al. Simulation of vacancy migration energy in Cu under high strain. Mater Sci Eng A, 2003, 350(1-2): 220 doi: 10.1016/S0921-5093(02)00692-5 -
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