TC4三层板结构超塑成形/扩散焊接工艺研究
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摘要
超塑成形/扩散焊接(简称SPF/DB)工艺,是南南南天领域成形研究的重要内容之一。钛合金多层板南心结构件由于其良好的结构形态、较轻的零件重量和简化的零件数量,一直以来是工艺应用的重点。目前钛合金SPF/DB工艺虽己进入使用阶段,但我国在SPF/DB技术上与发达国家相比还存在较大的差距。因此,开展钛合金等先进材料的SPF/DB技术研究,对降低成本,提高构件性能,增加飞机推重比具有非常重要的意义。本文结合数值模拟,采用先扩散焊接后超塑成形的方法,开展TC4三层板结构超塑成形/扩散焊接工艺研究和探讨。
本文首先依据超塑成形和扩散焊接基本原理和变形机理,确定TC4三层板结构SPF/DB的实验方案,提出显微组织分析焊合率和晶粒尺寸的方法,分析了超塑成形/扩散焊接过程的影响因素。
在理论和实验工艺的基础上,利用MARC软件对TC4三层板结构的超塑成形过程进行数值模拟,优化成形零件结构,预测成形零件的壁厚分布,讨论应变速率对成形结果与成形时间的影响,证明1x10-3 s-1为最佳成形应变速率,并获得最大应变速率恒定条件下的超塑成形压力—时间(p-t)曲线。
对成形零件壁厚分布情况及成形结果进行分析,根据不同扩散焊接部位的显微组织计算焊接接头的焊合率及晶粒尺寸,讨论不同变形量对晶粒尺寸影响。结果表明:成形零件整体壁厚均匀,最大减薄率为32%;扩散焊接接头的焊合率较高,最大值为100%;成形后晶粒尺寸较原始晶粒尺寸明显长大,并且芯板的左、右肋和成形圆角处的晶粒尺寸较其余部位小;成形零件上面板质量较好,下面板出现一处明显的沟槽,芯板成形较好。对比数值模拟结果与实验结果,表明二者吻合较好,数值模拟可靠。
Superplastic Forming and Diffusion Bonding (SPF/DB) process is one of the most important research subjects in the area-space engineering field. The titanium alloy multilayer sandwich structure is an important application in SPF/DB because of its perfect frame, low weight and few components. At present, the titanium alloy SPF/DB process has been taken into applied use in China, but there is a great gap compared with developed countries in the SPF/DB technology. So the research for titanium alloy and other advanced materials is carried out with SPF/DB process, which has extraordinarily magnitude significance to reduce costs, improve component performance and increase the aircraft thrust-weight ratio. In this thesis, the SPF/DB for three-sheet structure of Ti-6Al-4V titanium alloy was investigated combining numerical simulation by the method of SPF after DB.
Beginning with mechanism and deforming path of SPF/DB were investigated. Then the experimental project about the SPF/DB for three-sheet structure of Ti-6Al-4V was established, the method of microstructure analysis for the area-bonding ratio and grain side was advanced and the factors influencing process was discussed in this thesis.
Based on the theoretic and experiment, finite element simulation for SPF process was carried out on the software MARC which could optimize the forming part structure and predict the thickness distribution. The impact of strain rate on forming results and forming time was discussed, which also showed 1x10-3 s-1 was the best value of optimal strain rate. At the same time, the optimal SPF pressure-time curve was generated with the maximum constant strain rate control.
The SPF/DB for three-sheet structure of Ti-6Al-4V was investigated. The thickness distribution and forming result was analyze. The impact of different transmutation on grain side was discussed. At one time, the area-bonding ratio and grain side was computed. The results show that the thickness of forming part is uniformity on the whole and the maximum thinning rate is 32%. The area-bonding ratio is grate overall and the maximum value is 100%. Compared with the formed grain side, the original one is much smaller. The grain side of the left or right rib of the middle sheet and the forming fillet is least. The quality for the upper sheet of forming part is very good, while the lower sheet takes on mark-off and the profile of the middle sheet is perfect. In the end, comparing the numerical simulation result with the forming one, it proved that the numerical simulation was correct.
本文首先依据超塑成形和扩散焊接基本原理和变形机理,确定TC4三层板结构SPF/DB的实验方案,提出显微组织分析焊合率和晶粒尺寸的方法,分析了超塑成形/扩散焊接过程的影响因素。
在理论和实验工艺的基础上,利用MARC软件对TC4三层板结构的超塑成形过程进行数值模拟,优化成形零件结构,预测成形零件的壁厚分布,讨论应变速率对成形结果与成形时间的影响,证明1x10-3 s-1为最佳成形应变速率,并获得最大应变速率恒定条件下的超塑成形压力—时间(p-t)曲线。
对成形零件壁厚分布情况及成形结果进行分析,根据不同扩散焊接部位的显微组织计算焊接接头的焊合率及晶粒尺寸,讨论不同变形量对晶粒尺寸影响。结果表明:成形零件整体壁厚均匀,最大减薄率为32%;扩散焊接接头的焊合率较高,最大值为100%;成形后晶粒尺寸较原始晶粒尺寸明显长大,并且芯板的左、右肋和成形圆角处的晶粒尺寸较其余部位小;成形零件上面板质量较好,下面板出现一处明显的沟槽,芯板成形较好。对比数值模拟结果与实验结果,表明二者吻合较好,数值模拟可靠。
Superplastic Forming and Diffusion Bonding (SPF/DB) process is one of the most important research subjects in the area-space engineering field. The titanium alloy multilayer sandwich structure is an important application in SPF/DB because of its perfect frame, low weight and few components. At present, the titanium alloy SPF/DB process has been taken into applied use in China, but there is a great gap compared with developed countries in the SPF/DB technology. So the research for titanium alloy and other advanced materials is carried out with SPF/DB process, which has extraordinarily magnitude significance to reduce costs, improve component performance and increase the aircraft thrust-weight ratio. In this thesis, the SPF/DB for three-sheet structure of Ti-6Al-4V titanium alloy was investigated combining numerical simulation by the method of SPF after DB.
Beginning with mechanism and deforming path of SPF/DB were investigated. Then the experimental project about the SPF/DB for three-sheet structure of Ti-6Al-4V was established, the method of microstructure analysis for the area-bonding ratio and grain side was advanced and the factors influencing process was discussed in this thesis.
Based on the theoretic and experiment, finite element simulation for SPF process was carried out on the software MARC which could optimize the forming part structure and predict the thickness distribution. The impact of strain rate on forming results and forming time was discussed, which also showed 1x10-3 s-1 was the best value of optimal strain rate. At the same time, the optimal SPF pressure-time curve was generated with the maximum constant strain rate control.
The SPF/DB for three-sheet structure of Ti-6Al-4V was investigated. The thickness distribution and forming result was analyze. The impact of different transmutation on grain side was discussed. At one time, the area-bonding ratio and grain side was computed. The results show that the thickness of forming part is uniformity on the whole and the maximum thinning rate is 32%. The area-bonding ratio is grate overall and the maximum value is 100%. Compared with the formed grain side, the original one is much smaller. The grain side of the left or right rib of the middle sheet and the forming fillet is least. The quality for the upper sheet of forming part is very good, while the lower sheet takes on mark-off and the profile of the middle sheet is perfect. In the end, comparing the numerical simulation result with the forming one, it proved that the numerical simulation was correct.
引文
[1]王亚军,吴希孟,刘湘.南南制造技术发展趋势[J].科技中国, 2004, (8): 44-47.
[2]李梁,孙建科,孟祥军.钛合金超塑性研究及应用现状[J].材料开发与应用, 2004, 19(6): 34~38.
[3]李志强,郭和平.超塑成形/扩散焊接技术在南南南天工业中的应用[J].锻压技术, 2005, 30(1): 79~81.
[4]文九巴,杨蕴林,杨永顺等.超塑性应用技术[M].北南:机械工业出版社, 2005: 231~233.
[5] Hefti L D. Advances in fabricating superplastically formed and diffusion bonded components for aerospace structures[J]. Journal of Materials Engineering and Performance, 2004, 13(6): 678~682.
[6]刘莹,曲周德,王本贤.钛合金的研究开发和利用[J].兵器材料科学与工程, 2005, 12(1): 12~16.
[7] Farmsnesh K, Najafi-Zadeh A. Thermomechanical behavior of Ti-6Al-4V alloy[J]. Material Science Technology, 2003, 19(3): 217~220.
[8] Johnson C H. Microstructural and constitutive behavior of superplastic titanium alloy (Ti-6Al-4V)[D]. Washinton State University, 1994.
[9] Patankar etc S N, Escobedo J P, Field D P, et al. Superior superplastic behavior in fine-grained Ti-6Al-4V sheet[J]. Alloys and Compunds, 2002, 345(1-2): 221~227.
[10]陈科斌,张凯锋,王仲仁.板材超塑成形/扩散焊接过程的三维数值模拟[J].塑性工程学报, 1998, 20~25.
[11] Chen Y, Kibble K, Hall R, et al. Numerical analysis of superplastic blow forming of Ti-6Al-4V alloys[J]. Materials and Design, 2001, 22(8): 679~685.
[12]张家顺.美国宇南工业超塑成形近况[J].南南工艺技术, 1989, 6: 29~33.
[13]宋飞灵.英国超塑成形技术的应用现状[J].南南工艺技术, 1994, 3: 20~23.
[14]曹大明.英国宇南超塑成形/扩散焊接技术进展[J].国外南南工艺,1986, 3: 23~24.
[15]李志强,郭和平.超塑成形/扩散焊接技术应用与发展技术[J].南南制造技术, 2004, 11: 50~52.
[16] Dunford D V, Wisbey A. Diffusion bonding of advanced aerospace metallics [J]. Materials Research Society Symposium Proceedings, 1993, 314: 39~50.
[17]王哲.钛合金超塑成形/扩散焊接技术在飞机结构上的应用[J].钛工业进展, 1999, 3: 23~25.
[18]林兆荣.金属超塑性成形原理及应用[M].南南:南南工业出版社, 1990, 13~24.
[19] Kim Y H, Hong S S, Lee J S. Analysis of superplastic forming processes using a finite-element method[J]. Journal of Materials Processing Technology, 1996, 62: 90~99.
[20] ]Nazzal M A, Khraisheh M K, Darras B M. Finite element modeling and optimization of superplastic forming using variable strain rate approach[J]. Journal of Materials Engineering and Performance, 2004, 13(6): 691~699.
[21]谭红,连建设,胡平.材料参数及静水压力对南洞敏感材料超塑胀形影响的数值分析[J].南南材料工艺, 1997, 5: 43~45.
[22]向毅斌,吴诗惇.超塑性胀形成形时间影响因素的数值分析[J].模具技术, 2002, (2): ~14.
[23] Bonet J, Wood R D, Wargadipura A H S. Numerical simulation of the superplastic forming of thin sheet components using the finite element methods[J]. International Journal for numerical methods in Engineering, 1996, 30: 1719~1737.
[24] Chandra N, Rama S C, Rama J. Design and Analysis of 3-D superplastic forming processes[J]. Superplasticity in Advervanced Material– ICSAM-94, 1994, 170: 577~582.
[25]陈科斌,张凯锋,王仲仁.超塑成形/扩散焊接复合工艺过程数值模拟中新的接触检测算法[J].锻压技术, 1998, 4: 40~43.
[26]李靖谊,王卫英.控制超塑性充模胀形过程的计算机仿真技术[J].数据采集与处理, 1998, 13(4): 358~361.
[27]韩文波,张凯锋,王国峰等.钛合金四层板结构的超塑成形/扩散焊接工艺及数值模拟研究[J].第九届全国塑性工程学术年会论文摘要集, 2005: 56~59.
[28]金泉林.超塑变形的力学行为与本构描述.力学进展, 1995, 25(2): 260~274.
[29]邢会林,张凯锋,王仲仁.超塑性本构关系的研究[J].哈尔滨工业大学学报, 1994, 4(26): 101~105.
[30] Dunne F P E. Inhomogeneity of microstructure in superplasticity and its effect on ductility[J]. International Journal of Plasticity, 1998, 14(4): 413~433.
[31]陈浦泉.组织超塑性[M].黑龙江:哈尔滨工业大学出版社, 1988: 15~89.
[32]何景素,王燕文.金属的超塑性[M].北南:科学出版社, 1986: 199~215.
[33]卡伊勃舍夫.金属的塑性与超塑性[M].北南:机械工业出版社, 1982: 11~209.
[34]卡扎柯夫.材料的扩散焊接[M].北南:国防工业出版社, 1982: 19~25.
[35] Daniel G, Sanders A, Mamidala R. Examination of superplastic forming combined with diffusion bonding for titanium: perspective from experience[J]. Materials Engineering and Performance, 2004, 13(6): 744~752.
[36]韩文波.多层板结构超塑成形/扩散焊接工艺及数值模拟研究[D].黑龙江:哈尔滨工业大学, 2004.
[37] Xiang Y, Wu S. Fracture toughness of superplastic formed/diffusion bonded interfaces[J]. Materials Engineering and Performance, 2001, 10(6): 67~684.
[38]郭伟,赵熹华,宋敏霞.扩散焊接界面理论的现状和发展[J].南天制造技术, 2004, 4: 36~39.
[39]赵毅,陶华.钛合金板超塑性成形/扩散焊接成形因素影响的数值模拟[J].南南精密制造技术, 2007, 43(1): 41-43.
[40]秦国友.定量金相[M].四川:四川科学技术出版社, 1987, 80~83.
[41] Xun Y W, Tan M J. Application of superplastic forming and diffusion bonding to hollow engine blades [J]. Materials Processing Technology, 2000, 99(8): 8~85.
[42]吴为,张凯锋. TB2钛合金扩散焊接头强度的影响因素[J].宇南材料工艺, 2002, 2: 5~58.
[43]徐杰.镁合金活性TIG焊和真南扩散焊的研究[D].江苏:南南南南南天大学, 2006.
[44]梁清香,张根全.有限元与MARC实现[M].北南:机械工业出版社, 2003: 8~9.
[45]陈火红. MARC有限元实例分析教程[M].北南:机械工业出版社, 2002: 3~4.
[46]向毅斌.超塑性板料成形模拟及扩散焊接件界面断裂韧性分析[D].陕西:西北工业大学, 2001.
[47] Verma R, Kim S, Superplastic behavior of copper-modified 5083 aluminum alloy [J]. Materials Engineering and Performance, 2007, 16(2): 18~191.
[48] Gao M, AI J L. Optimum design of titanium alloy SPF/DB structure based on the MSC Nastran [J]. China Mechanical Engineering, 2005, 16(19): 54~61.
[49]王华侨.结构有限元分析中的网格划分技术及其应用实例[J]. CAD/CAM与制造业信息化, 2005, 1: 42~47.
[50]王纯孝.超塑成形工艺技术及设备[J].南南工艺技术, 1996, 5: 83~107.
[51]唐黎明.超塑性气压胀形测控系统的设计与实现[D].江苏:南南南南南天大学, 2006.
[52]葛永成.锥形件超塑胀形实验研究[D].江苏:南南南南南天大学, 2008.
[53]蒋钦元.钛合金超塑成形模具材料的选用[J].南南工艺技术, 1994, 3: 1~14.
[54]施晓琦.钛合金超塑性成形/扩散焊接组合工艺研究[D].江苏:南南南南南天大学, 2007.
[55]陈溥泉.锌合金模具和锌合金超塑性成形技术[M].哈尔滨,哈尔滨工业大学出版社, 1985.
[56] Larry D H. Innovations in the superplastic forming and diffusion bonding process[J]. Materials Engineering and Performance, 2008, 17(2): 178~182.
[57] Boner J, Wood R D, Collins R. Pressure-control algorithms for the numerical simulation of superplastic forming[J]. International Journal of Mechanical Sciences, 1994, 36(41): 29~309.
[58]朱康英.α+β钛合金特细等轴晶粒的细化和机械性能的改善[J].钛工业进展, 1995,2: 22 ~26.
[59] Backofen W A, Turner I R, Avery D H. Superplasticity in an Al-Zn Alloy [J]. Asm Trans, 1964, 57(6): 980~990.
[60] Lee H S, Yoon J, Yi Y M, et al. Fabrication of sandwich structure with superplastic forming process from diffusionbonded Ti-6Al-4V sheets [J]. Advanced Materials Research, 2007, 26(28): 359~362.
[2]李梁,孙建科,孟祥军.钛合金超塑性研究及应用现状[J].材料开发与应用, 2004, 19(6): 34~38.
[3]李志强,郭和平.超塑成形/扩散焊接技术在南南南天工业中的应用[J].锻压技术, 2005, 30(1): 79~81.
[4]文九巴,杨蕴林,杨永顺等.超塑性应用技术[M].北南:机械工业出版社, 2005: 231~233.
[5] Hefti L D. Advances in fabricating superplastically formed and diffusion bonded components for aerospace structures[J]. Journal of Materials Engineering and Performance, 2004, 13(6): 678~682.
[6]刘莹,曲周德,王本贤.钛合金的研究开发和利用[J].兵器材料科学与工程, 2005, 12(1): 12~16.
[7] Farmsnesh K, Najafi-Zadeh A. Thermomechanical behavior of Ti-6Al-4V alloy[J]. Material Science Technology, 2003, 19(3): 217~220.
[8] Johnson C H. Microstructural and constitutive behavior of superplastic titanium alloy (Ti-6Al-4V)[D]. Washinton State University, 1994.
[9] Patankar etc S N, Escobedo J P, Field D P, et al. Superior superplastic behavior in fine-grained Ti-6Al-4V sheet[J]. Alloys and Compunds, 2002, 345(1-2): 221~227.
[10]陈科斌,张凯锋,王仲仁.板材超塑成形/扩散焊接过程的三维数值模拟[J].塑性工程学报, 1998, 20~25.
[11] Chen Y, Kibble K, Hall R, et al. Numerical analysis of superplastic blow forming of Ti-6Al-4V alloys[J]. Materials and Design, 2001, 22(8): 679~685.
[12]张家顺.美国宇南工业超塑成形近况[J].南南工艺技术, 1989, 6: 29~33.
[13]宋飞灵.英国超塑成形技术的应用现状[J].南南工艺技术, 1994, 3: 20~23.
[14]曹大明.英国宇南超塑成形/扩散焊接技术进展[J].国外南南工艺,1986, 3: 23~24.
[15]李志强,郭和平.超塑成形/扩散焊接技术应用与发展技术[J].南南制造技术, 2004, 11: 50~52.
[16] Dunford D V, Wisbey A. Diffusion bonding of advanced aerospace metallics [J]. Materials Research Society Symposium Proceedings, 1993, 314: 39~50.
[17]王哲.钛合金超塑成形/扩散焊接技术在飞机结构上的应用[J].钛工业进展, 1999, 3: 23~25.
[18]林兆荣.金属超塑性成形原理及应用[M].南南:南南工业出版社, 1990, 13~24.
[19] Kim Y H, Hong S S, Lee J S. Analysis of superplastic forming processes using a finite-element method[J]. Journal of Materials Processing Technology, 1996, 62: 90~99.
[20] ]Nazzal M A, Khraisheh M K, Darras B M. Finite element modeling and optimization of superplastic forming using variable strain rate approach[J]. Journal of Materials Engineering and Performance, 2004, 13(6): 691~699.
[21]谭红,连建设,胡平.材料参数及静水压力对南洞敏感材料超塑胀形影响的数值分析[J].南南材料工艺, 1997, 5: 43~45.
[22]向毅斌,吴诗惇.超塑性胀形成形时间影响因素的数值分析[J].模具技术, 2002, (2): ~14.
[23] Bonet J, Wood R D, Wargadipura A H S. Numerical simulation of the superplastic forming of thin sheet components using the finite element methods[J]. International Journal for numerical methods in Engineering, 1996, 30: 1719~1737.
[24] Chandra N, Rama S C, Rama J. Design and Analysis of 3-D superplastic forming processes[J]. Superplasticity in Advervanced Material– ICSAM-94, 1994, 170: 577~582.
[25]陈科斌,张凯锋,王仲仁.超塑成形/扩散焊接复合工艺过程数值模拟中新的接触检测算法[J].锻压技术, 1998, 4: 40~43.
[26]李靖谊,王卫英.控制超塑性充模胀形过程的计算机仿真技术[J].数据采集与处理, 1998, 13(4): 358~361.
[27]韩文波,张凯锋,王国峰等.钛合金四层板结构的超塑成形/扩散焊接工艺及数值模拟研究[J].第九届全国塑性工程学术年会论文摘要集, 2005: 56~59.
[28]金泉林.超塑变形的力学行为与本构描述.力学进展, 1995, 25(2): 260~274.
[29]邢会林,张凯锋,王仲仁.超塑性本构关系的研究[J].哈尔滨工业大学学报, 1994, 4(26): 101~105.
[30] Dunne F P E. Inhomogeneity of microstructure in superplasticity and its effect on ductility[J]. International Journal of Plasticity, 1998, 14(4): 413~433.
[31]陈浦泉.组织超塑性[M].黑龙江:哈尔滨工业大学出版社, 1988: 15~89.
[32]何景素,王燕文.金属的超塑性[M].北南:科学出版社, 1986: 199~215.
[33]卡伊勃舍夫.金属的塑性与超塑性[M].北南:机械工业出版社, 1982: 11~209.
[34]卡扎柯夫.材料的扩散焊接[M].北南:国防工业出版社, 1982: 19~25.
[35] Daniel G, Sanders A, Mamidala R. Examination of superplastic forming combined with diffusion bonding for titanium: perspective from experience[J]. Materials Engineering and Performance, 2004, 13(6): 744~752.
[36]韩文波.多层板结构超塑成形/扩散焊接工艺及数值模拟研究[D].黑龙江:哈尔滨工业大学, 2004.
[37] Xiang Y, Wu S. Fracture toughness of superplastic formed/diffusion bonded interfaces[J]. Materials Engineering and Performance, 2001, 10(6): 67~684.
[38]郭伟,赵熹华,宋敏霞.扩散焊接界面理论的现状和发展[J].南天制造技术, 2004, 4: 36~39.
[39]赵毅,陶华.钛合金板超塑性成形/扩散焊接成形因素影响的数值模拟[J].南南精密制造技术, 2007, 43(1): 41-43.
[40]秦国友.定量金相[M].四川:四川科学技术出版社, 1987, 80~83.
[41] Xun Y W, Tan M J. Application of superplastic forming and diffusion bonding to hollow engine blades [J]. Materials Processing Technology, 2000, 99(8): 8~85.
[42]吴为,张凯锋. TB2钛合金扩散焊接头强度的影响因素[J].宇南材料工艺, 2002, 2: 5~58.
[43]徐杰.镁合金活性TIG焊和真南扩散焊的研究[D].江苏:南南南南南天大学, 2006.
[44]梁清香,张根全.有限元与MARC实现[M].北南:机械工业出版社, 2003: 8~9.
[45]陈火红. MARC有限元实例分析教程[M].北南:机械工业出版社, 2002: 3~4.
[46]向毅斌.超塑性板料成形模拟及扩散焊接件界面断裂韧性分析[D].陕西:西北工业大学, 2001.
[47] Verma R, Kim S, Superplastic behavior of copper-modified 5083 aluminum alloy [J]. Materials Engineering and Performance, 2007, 16(2): 18~191.
[48] Gao M, AI J L. Optimum design of titanium alloy SPF/DB structure based on the MSC Nastran [J]. China Mechanical Engineering, 2005, 16(19): 54~61.
[49]王华侨.结构有限元分析中的网格划分技术及其应用实例[J]. CAD/CAM与制造业信息化, 2005, 1: 42~47.
[50]王纯孝.超塑成形工艺技术及设备[J].南南工艺技术, 1996, 5: 83~107.
[51]唐黎明.超塑性气压胀形测控系统的设计与实现[D].江苏:南南南南南天大学, 2006.
[52]葛永成.锥形件超塑胀形实验研究[D].江苏:南南南南南天大学, 2008.
[53]蒋钦元.钛合金超塑成形模具材料的选用[J].南南工艺技术, 1994, 3: 1~14.
[54]施晓琦.钛合金超塑性成形/扩散焊接组合工艺研究[D].江苏:南南南南南天大学, 2007.
[55]陈溥泉.锌合金模具和锌合金超塑性成形技术[M].哈尔滨,哈尔滨工业大学出版社, 1985.
[56] Larry D H. Innovations in the superplastic forming and diffusion bonding process[J]. Materials Engineering and Performance, 2008, 17(2): 178~182.
[57] Boner J, Wood R D, Collins R. Pressure-control algorithms for the numerical simulation of superplastic forming[J]. International Journal of Mechanical Sciences, 1994, 36(41): 29~309.
[58]朱康英.α+β钛合金特细等轴晶粒的细化和机械性能的改善[J].钛工业进展, 1995,2: 22 ~26.
[59] Backofen W A, Turner I R, Avery D H. Superplasticity in an Al-Zn Alloy [J]. Asm Trans, 1964, 57(6): 980~990.
[60] Lee H S, Yoon J, Yi Y M, et al. Fabrication of sandwich structure with superplastic forming process from diffusionbonded Ti-6Al-4V sheets [J]. Advanced Materials Research, 2007, 26(28): 359~362.
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