热处理工艺对喷射成形Al-Zn-Mg-Cu系高强铝合金组织和性能影响
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摘要
本文以喷射成形Al-Zn-Mg-Cu系超高强铝合金为对象,研究了热处理对合金组织和性能的影响。经研究发现,固溶温度对合金的组织和性能影响较大,采用双级固溶470℃×2h+490℃×1h可以保证不发生过烧前提下,最大程度使合金中的各种析出相回溶,最后的到合金的最优化热处理工艺。
合金的析出行为与时效硬化和电导率特性具有一定的对应关系,因此有必要对合金的时效硬化和电导率特性经行研究。针对单级时效硬化特性的研究发现,喷射成形Al-Zn-Mg-Cu系超高强铝合金时效硬化具有双峰的特点,峰时效时间为19h左右,与之对应的合金的最高强度为800MPa左右。相比之下,双级时效合金的强度下降了8%左右。利用Starink模型对合金的电导率进行研究,发现合金的电导率与时效时间、时效温度和溶解到基体中的合金元素的数量有关,时效时间越长,时效温度越高,合金的电导率越高,溶解到集体中合金元素量越多,溶解的合金元素种类越多,合金的电导率越低。
用透射电镜对合金的析出特性研究发现,单级时效达到峰时效后,晶内析出的沉淀相呈细小的球状,比较规则,尺寸在几nm左右,弥散分布在晶粒内部。经过对选区电子衍射花样及X射线衍射谱的标定,确认晶内沉淀相为η'相X ray diffraction - XRD也证明了这一相,随着时间的延长η'逐渐长大粗化,并向η相转变。双级时效时,随着时间的延长,沉淀相遵循—GP区→η'过渡相(MgZn)→η(MgZn_2)稳定相这一转化规律。
喷射成形高强铝合金的断裂方式为韧性断裂,部分韧窝中可看到第二相颗粒。峰时效拉伸断口形成大量的韧窝,过时效随着时间的延长,合金的断裂方式由韧窝断裂向穿晶断裂转变,合金的塑性逐渐降低。
In this paper, we studied the effect of heat treatment on the microstructure and properties of the spray forming Al-Zn-Mg-Cu ultra-high strength aluminum alloy. Results show that solid solution temperature had an important effect on the alloy performance of the organization, two-step solid solution using 470℃×2h +490℃×1h to ensure that burning does not happen under the premise of the greatest extent variety of alloy precipitates back dissolved, at last we get the final optimization of the alloy heat treatment process.
Alloy age-hardening and precipitation behavior and electrical conductivity properties have a certain relationship, it is essential to study the age-hardening alloy properties and electrical conductivity. By the study of single-stage age-hardening characteristics of the found that spray forming Al-Zn-Mg-Cu Department of ultra high strength aluminum alloy with a bimodal age-hardening characteristics, peak aging time for the 19h, which corresponds to the maximum strength of alloys of about 800MPa. In contrast, Two-step aging treatment of alloy decreased the intensity of about 8%. Starink model using the conductivity of the alloy to study and found that the conductivity of alloys related with aging time, aging temperature and dissolved into the matrix of the number of alloying elements, and spent a longer time, the higher the aging temperature, the higher the conductivity alloy had ,and vice versa.
By transmission electron microscopy-TEM study of precipitation characteristics, single-stage aging after reaching peak aging, the precipitation of intragranular precipitates were small spherical, more rules, the size at about few nm, the internal diffusion in the grain. After the demarcation of selected area electron diffraction pattern, we think that this phase ofη', X ray diffraction - XRD has proved that this phase. With the time,η' coarsening, gradually grew to theηphase. Two-step aging treatment, as time lengthens, the precipitation follow this GP→η'phase (MgZn)→η
The way of ductile of spray forming of high strength aluminum alloy belongs to dimple fracture, and some second phase particles can be seen in the dimples. Peak ageing time formed a lot for dimples at the tensile fracture. with the extension of the time of two-step aging treatment, the way of ductile change into transcrystalline fracture and the plastic of alloy become lower.
合金的析出行为与时效硬化和电导率特性具有一定的对应关系,因此有必要对合金的时效硬化和电导率特性经行研究。针对单级时效硬化特性的研究发现,喷射成形Al-Zn-Mg-Cu系超高强铝合金时效硬化具有双峰的特点,峰时效时间为19h左右,与之对应的合金的最高强度为800MPa左右。相比之下,双级时效合金的强度下降了8%左右。利用Starink模型对合金的电导率进行研究,发现合金的电导率与时效时间、时效温度和溶解到基体中的合金元素的数量有关,时效时间越长,时效温度越高,合金的电导率越高,溶解到集体中合金元素量越多,溶解的合金元素种类越多,合金的电导率越低。
用透射电镜对合金的析出特性研究发现,单级时效达到峰时效后,晶内析出的沉淀相呈细小的球状,比较规则,尺寸在几nm左右,弥散分布在晶粒内部。经过对选区电子衍射花样及X射线衍射谱的标定,确认晶内沉淀相为η'相X ray diffraction - XRD也证明了这一相,随着时间的延长η'逐渐长大粗化,并向η相转变。双级时效时,随着时间的延长,沉淀相遵循—GP区→η'过渡相(MgZn)→η(MgZn_2)稳定相这一转化规律。
喷射成形高强铝合金的断裂方式为韧性断裂,部分韧窝中可看到第二相颗粒。峰时效拉伸断口形成大量的韧窝,过时效随着时间的延长,合金的断裂方式由韧窝断裂向穿晶断裂转变,合金的塑性逐渐降低。
In this paper, we studied the effect of heat treatment on the microstructure and properties of the spray forming Al-Zn-Mg-Cu ultra-high strength aluminum alloy. Results show that solid solution temperature had an important effect on the alloy performance of the organization, two-step solid solution using 470℃×2h +490℃×1h to ensure that burning does not happen under the premise of the greatest extent variety of alloy precipitates back dissolved, at last we get the final optimization of the alloy heat treatment process.
Alloy age-hardening and precipitation behavior and electrical conductivity properties have a certain relationship, it is essential to study the age-hardening alloy properties and electrical conductivity. By the study of single-stage age-hardening characteristics of the found that spray forming Al-Zn-Mg-Cu Department of ultra high strength aluminum alloy with a bimodal age-hardening characteristics, peak aging time for the 19h, which corresponds to the maximum strength of alloys of about 800MPa. In contrast, Two-step aging treatment of alloy decreased the intensity of about 8%. Starink model using the conductivity of the alloy to study and found that the conductivity of alloys related with aging time, aging temperature and dissolved into the matrix of the number of alloying elements, and spent a longer time, the higher the aging temperature, the higher the conductivity alloy had ,and vice versa.
By transmission electron microscopy-TEM study of precipitation characteristics, single-stage aging after reaching peak aging, the precipitation of intragranular precipitates were small spherical, more rules, the size at about few nm, the internal diffusion in the grain. After the demarcation of selected area electron diffraction pattern, we think that this phase ofη', X ray diffraction - XRD has proved that this phase. With the time,η' coarsening, gradually grew to theηphase. Two-step aging treatment, as time lengthens, the precipitation follow this GP→η'phase (MgZn)→η
The way of ductile of spray forming of high strength aluminum alloy belongs to dimple fracture, and some second phase particles can be seen in the dimples. Peak ageing time formed a lot for dimples at the tensile fracture. with the extension of the time of two-step aging treatment, the way of ductile change into transcrystalline fracture and the plastic of alloy become lower.
引文
1 J. N. Fridlyander, O. G. Senatorova. Development and application of high-strength Al-Zn-Mg-Cu alloys. Transtec Publications Ltd. 1996:1813~1818
2 Lukaska D A, Hart R M. Strong Aluminum Alloy Shave Airframe Weight Advanced Materials and Proceses. 1991, 10:46
3马场义雄.超硬铝[ESD]及飞机铝合金发展动向.铝加工技术. 1990,4(3): 21~31
4吴一雷,李永伟,强俊,李春玉.超高强度铝合金的发展与应用.航空材料学报. 1994, 14(1): 45-49
5 G. B. Schaffer, S. H. Huo. On development of sintered 7000 series aluminium alloys. Powder Metallurgy. 1999,42(3):219~226
6 J. T. Staley. ALUMINUM ALLOYS FOR AEROSTRUCTURES. Advanced Materials Process. 1997,152(4):17~20
7张永昌.金属喷射成形的进展.粉末冶金工业. 2001,11(6):17~22
8彭超群,黄伯云.喷射沉积技术.有色金属, 2002, 54(1):12~13
9 V. C.Srivastava, K. Mandal N.Ojha. Microstructure and mechanical properties of Al-Si alloys produced by spray forming process . Materials Science and Engineering , 001:555~558
10康福伟,孙剑飞,沈军等.喷射成形工艺的发展及应用.稀有金属, 2004, 28(3):405
11王军,严彪,徐政.喷射成形技术的发展与应用.上海有色金属, 2002,23(3):135
12 R. Knight, R. W. Smith, A. Lawley. Spray Forming Research at Drexel University. International Journey of Poweder Metallurgy. 1995, 31(3):205-213
13熊柏青,张永安,石力开.喷射成形制备高性能铝合金材料.材料导报, 2000, 14(12):50-55
14 M. De Sanctis. Structure and Properties of Rapidly Solidified Ultrahigh strength Al-Zn-Mg-Cu Alloys Produced by Spray Deposition. Materials Science and Engineering. 1991, A141:103-121
15 R. Machler, P. J. Uggowitzer, C.Solenthaler, et al.Structure , Mechanical Properties , and Stress Corrosion Behaviour of High Strength Spray Deposited 7000 Series Aluminium Alloy. Materials Science and Technology. 1991, 7:447-451
16 J.A. Juarrez-Islas, R. Perez et al. Microstrural and Mechanical Evaluations of Spay-deposited 7000 Al-alloys after Conventional Consolidation. Materials Science and Engineering. 1994, A179/A180:614-618
17 Srivatsan, Vasudevan V K Temperature and the ducitility, deformation, and fractureof Al 7055 [J]. JOM, 1999, 1:42.
18 Leatham A G. Spray forming:alloys, products, and markets. Fourth Internation Conference on Spray forming[C].Baltimore, USA, 1999
19 Lengsfeld P, Juarez A, Lavernia EJ, et al. Microstructure and mechanical behavior of spray deposited Zn modified 7000 Al alloys. Inter. J. Rap.Sol, 1995, ,8 :237
20王祝堂,田荣璋,铝合金及其加工手册.长沙:中南大学出版社, 2000
21 Wei Qiang, Xiong Baiqi, Zhang Yongan. Production of high strength Al-Zn-Mg-Cu alloys by spray forming process. Trans nonferrous Met. Soc. China, 2001, 11(2):258
22祝铭亮,周铁涛,刘培英,等.最初形成的喷射沉积Al-Zn-Mg-Cu铝合金的显微组织分析.稀有金属, 2003, 27(4): 455.
23 Leatham A. G.. The Process of the Fourth International Conference on Spray Forming, Baltimore, USA. 1999
24熊柏青,朱宝宏,石力开,王洪斌,张济山. Al10Zn2.9Mg1.7Cu超高强铝合金的喷射成形制备研究.稀有金属, 2003, Vol. 27 (5)
25 T. Gladman, Precipitation Hardening in Matals. Materials Science Technology 1999, 15:30-36
26 H. P. Degischer, W. Lacom, A. Zahra, C. Y. Zahra. Decomposition processes in an Al-5-percent-Zn-l-percent-Mg alloy, 2. Electron microscopic investigations. Z Metallkd. 1980,71(231~238)
27 G. Sha, A. Cerezo. Early-stage precipitation in Al-Zn-Mg-Cu alloy (7050). Acta Materialia. 2004,52(15):4503~4516
28王一鑫. Al-Zn-Mg-Cu系高强铝合金快速凝固条件下微合金化作用机理,哈尔滨工业大学硕士学位论文2008, 07
29 Wei Qiang. Production of high strength Al-Zn-Mg-Cu alloys by spray forming process. Trans. Norferrous Met. Soc. China. 2002, 11(4):258-261
30杨林,田冲等.喷射沉积AlZn12Mg2Cu2合金的组织结构及力学性能.材料科学工程. 2002(2):23-26
31郭舒.喷射成型超高强铝合金组织控制与时效行为.哈尔滨工业大学硕士学位论文. 2005
32 E.C.Zwickan, U. T .Freiberg. Possibilities for the Heat Treatment Diagrams for Industrial Al-Zn-Mg-Cu alloy. Aluminum. 1999, 75:90-96
33 Kanghua Chen. The Improvement of Constituent Dissolution and Mechanical Properties of 7055 Aluminum Alloy by Stepped Heat Treatment. Journal of Materials Processing Technology. 2003, 142:190-196
34万福高,热处理工艺对7150铝合金组织和性能影响的研究,哈尔滨工业大学硕士毕业论文,2007, 07
35 B. Q. Xiong, Y. A. Zhang, B. H. Zhu, H. W. Liu, Z. H. Zhang, L. K. Shi. Research on ultra-high strength Al-11Zn-2.9Mg-1.7Cu alloy prepared by spray forming process. Transanction Technology Publications Ltd, 2005:2785~2788
36刘红卫,陈康华.强化固溶对7075铝合金组织和性能的影响.金属热处理. 2000, 10(6):24-27.
37 Bruce M, Claire M, Ravi S, et. al. The Influence of Al3Zr Dispersoids on the Recrystallization of Hot-deformed AA7010 Alloys. Metallurgical and Materials Transactions A. 2001, 32(3):625-632.
38 M. J. Starink, X. M. Li. A modle for the electrical conductivity of peak -aged and overaged Al-Zn-Mg-Cu alloys. Metallurgical and Matericals Transactions A, 2003, 34A:899-911
39金属学与热处理原理,崔忠圻,刘北兴.哈尔滨工业大学出版社, 1998,9:(216-219)
40唐文冠,赖祖涵,万华明. 7050铝合金时效动力学研究.江西科学,1992, 10(1):19-27
41宋仁国,张宝金,曾梅光等. 7175铝合金时效"双峰",应力腐蚀敏感性的研究.金属热处理学报, 1996, 17(2):51-54
42秦凤香,张宝金等. 7055超高强铝合金时效硬化特性与应力腐蚀性能研究(J),轻合金加工技术, 2001, 29(10):36-39
43 S .Iwamura, Loss in coherency and coarsening behavior of Al3Sc precipitates Acta Materialia. 2004,52(3): 591~600
44樊喜刚. Al-Zn-Mg-Cu合金组织性能和断裂行为的研究.哈尔滨工业大学工学博士论文, 2007, 03: (71-75)
45 K. Stiller, P. J. Warren, V. Hansen. Investigation of precipitation in an Al-Zn-Mg alloy afer two-step aging treatment at 100℃and 150℃, Materials Science and Engineering A270 (1999) 55-63
46 Characterization and modeling of precipitaion kinetics in an Al-Zn-Mg alloy Materials Science and Engineering A270 (1999) 267-274
47 G. M. Ludtra, D. E. Laughlin. The influence of microstructure and strength on the fracture mode and toughness of 7000 series aluminum alloys. Metal Trans. 1982, 13(3):411-414
2 Lukaska D A, Hart R M. Strong Aluminum Alloy Shave Airframe Weight Advanced Materials and Proceses. 1991, 10:46
3马场义雄.超硬铝[ESD]及飞机铝合金发展动向.铝加工技术. 1990,4(3): 21~31
4吴一雷,李永伟,强俊,李春玉.超高强度铝合金的发展与应用.航空材料学报. 1994, 14(1): 45-49
5 G. B. Schaffer, S. H. Huo. On development of sintered 7000 series aluminium alloys. Powder Metallurgy. 1999,42(3):219~226
6 J. T. Staley. ALUMINUM ALLOYS FOR AEROSTRUCTURES. Advanced Materials Process. 1997,152(4):17~20
7张永昌.金属喷射成形的进展.粉末冶金工业. 2001,11(6):17~22
8彭超群,黄伯云.喷射沉积技术.有色金属, 2002, 54(1):12~13
9 V. C.Srivastava, K. Mandal N.Ojha. Microstructure and mechanical properties of Al-Si alloys produced by spray forming process . Materials Science and Engineering , 001:555~558
10康福伟,孙剑飞,沈军等.喷射成形工艺的发展及应用.稀有金属, 2004, 28(3):405
11王军,严彪,徐政.喷射成形技术的发展与应用.上海有色金属, 2002,23(3):135
12 R. Knight, R. W. Smith, A. Lawley. Spray Forming Research at Drexel University. International Journey of Poweder Metallurgy. 1995, 31(3):205-213
13熊柏青,张永安,石力开.喷射成形制备高性能铝合金材料.材料导报, 2000, 14(12):50-55
14 M. De Sanctis. Structure and Properties of Rapidly Solidified Ultrahigh strength Al-Zn-Mg-Cu Alloys Produced by Spray Deposition. Materials Science and Engineering. 1991, A141:103-121
15 R. Machler, P. J. Uggowitzer, C.Solenthaler, et al.Structure , Mechanical Properties , and Stress Corrosion Behaviour of High Strength Spray Deposited 7000 Series Aluminium Alloy. Materials Science and Technology. 1991, 7:447-451
16 J.A. Juarrez-Islas, R. Perez et al. Microstrural and Mechanical Evaluations of Spay-deposited 7000 Al-alloys after Conventional Consolidation. Materials Science and Engineering. 1994, A179/A180:614-618
17 Srivatsan, Vasudevan V K Temperature and the ducitility, deformation, and fractureof Al 7055 [J]. JOM, 1999, 1:42.
18 Leatham A G. Spray forming:alloys, products, and markets. Fourth Internation Conference on Spray forming[C].Baltimore, USA, 1999
19 Lengsfeld P, Juarez A, Lavernia EJ, et al. Microstructure and mechanical behavior of spray deposited Zn modified 7000 Al alloys. Inter. J. Rap.Sol, 1995, ,8 :237
20王祝堂,田荣璋,铝合金及其加工手册.长沙:中南大学出版社, 2000
21 Wei Qiang, Xiong Baiqi, Zhang Yongan. Production of high strength Al-Zn-Mg-Cu alloys by spray forming process. Trans nonferrous Met. Soc. China, 2001, 11(2):258
22祝铭亮,周铁涛,刘培英,等.最初形成的喷射沉积Al-Zn-Mg-Cu铝合金的显微组织分析.稀有金属, 2003, 27(4): 455.
23 Leatham A. G.. The Process of the Fourth International Conference on Spray Forming, Baltimore, USA. 1999
24熊柏青,朱宝宏,石力开,王洪斌,张济山. Al10Zn2.9Mg1.7Cu超高强铝合金的喷射成形制备研究.稀有金属, 2003, Vol. 27 (5)
25 T. Gladman, Precipitation Hardening in Matals. Materials Science Technology 1999, 15:30-36
26 H. P. Degischer, W. Lacom, A. Zahra, C. Y. Zahra. Decomposition processes in an Al-5-percent-Zn-l-percent-Mg alloy, 2. Electron microscopic investigations. Z Metallkd. 1980,71(231~238)
27 G. Sha, A. Cerezo. Early-stage precipitation in Al-Zn-Mg-Cu alloy (7050). Acta Materialia. 2004,52(15):4503~4516
28王一鑫. Al-Zn-Mg-Cu系高强铝合金快速凝固条件下微合金化作用机理,哈尔滨工业大学硕士学位论文2008, 07
29 Wei Qiang. Production of high strength Al-Zn-Mg-Cu alloys by spray forming process. Trans. Norferrous Met. Soc. China. 2002, 11(4):258-261
30杨林,田冲等.喷射沉积AlZn12Mg2Cu2合金的组织结构及力学性能.材料科学工程. 2002(2):23-26
31郭舒.喷射成型超高强铝合金组织控制与时效行为.哈尔滨工业大学硕士学位论文. 2005
32 E.C.Zwickan, U. T .Freiberg. Possibilities for the Heat Treatment Diagrams for Industrial Al-Zn-Mg-Cu alloy. Aluminum. 1999, 75:90-96
33 Kanghua Chen. The Improvement of Constituent Dissolution and Mechanical Properties of 7055 Aluminum Alloy by Stepped Heat Treatment. Journal of Materials Processing Technology. 2003, 142:190-196
34万福高,热处理工艺对7150铝合金组织和性能影响的研究,哈尔滨工业大学硕士毕业论文,2007, 07
35 B. Q. Xiong, Y. A. Zhang, B. H. Zhu, H. W. Liu, Z. H. Zhang, L. K. Shi. Research on ultra-high strength Al-11Zn-2.9Mg-1.7Cu alloy prepared by spray forming process. Transanction Technology Publications Ltd, 2005:2785~2788
36刘红卫,陈康华.强化固溶对7075铝合金组织和性能的影响.金属热处理. 2000, 10(6):24-27.
37 Bruce M, Claire M, Ravi S, et. al. The Influence of Al3Zr Dispersoids on the Recrystallization of Hot-deformed AA7010 Alloys. Metallurgical and Materials Transactions A. 2001, 32(3):625-632.
38 M. J. Starink, X. M. Li. A modle for the electrical conductivity of peak -aged and overaged Al-Zn-Mg-Cu alloys. Metallurgical and Matericals Transactions A, 2003, 34A:899-911
39金属学与热处理原理,崔忠圻,刘北兴.哈尔滨工业大学出版社, 1998,9:(216-219)
40唐文冠,赖祖涵,万华明. 7050铝合金时效动力学研究.江西科学,1992, 10(1):19-27
41宋仁国,张宝金,曾梅光等. 7175铝合金时效"双峰",应力腐蚀敏感性的研究.金属热处理学报, 1996, 17(2):51-54
42秦凤香,张宝金等. 7055超高强铝合金时效硬化特性与应力腐蚀性能研究(J),轻合金加工技术, 2001, 29(10):36-39
43 S .Iwamura, Loss in coherency and coarsening behavior of Al3Sc precipitates Acta Materialia. 2004,52(3): 591~600
44樊喜刚. Al-Zn-Mg-Cu合金组织性能和断裂行为的研究.哈尔滨工业大学工学博士论文, 2007, 03: (71-75)
45 K. Stiller, P. J. Warren, V. Hansen. Investigation of precipitation in an Al-Zn-Mg alloy afer two-step aging treatment at 100℃and 150℃, Materials Science and Engineering A270 (1999) 55-63
46 Characterization and modeling of precipitaion kinetics in an Al-Zn-Mg alloy Materials Science and Engineering A270 (1999) 267-274
47 G. M. Ludtra, D. E. Laughlin. The influence of microstructure and strength on the fracture mode and toughness of 7000 series aluminum alloys. Metal Trans. 1982, 13(3):411-414