AZ31和AM30镁合金管材弯曲成形及变形机理研究
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摘要
镁合金挤压管材成形容易、尺寸精度高、组织致密、机械性能高,可最大限度地实现材料结构一体化减重,是未来大规模推广镁合金应用的重点。管材的成功应用离不开弯曲、涨形、缩管等二次加工,但密排六方结构的镁合金室温塑性变形能力弱,无法照搬钢、铝、铜等的二次塑性成形工艺,所以,本文系统地研究了AZ31和AM30镁合金挤压管材的弯曲成形性能及其变形形为,希望为镁合金管材的规模应用提供一定的理论指导和实践借鉴。
挤压成型了AZ31和AM30两种合金管材,并分析了它们的微观组织、室温和高温力学性能。结果表明两种合金在挤压时均发生了完全动态再结晶,形成了由大角度晶界组成的等轴晶及c轴垂直于挤压方向的丝织构,但在相同的挤压工艺下,AM30合金管材的晶粒更加细小,分布均匀。随挤压温度的升高,AM30合金管材的晶粒度增大,室温拉伸强度降低,延伸率升高;低温挤压得到的细晶管材变形时孪晶被抑制,丝织构导致基面位滑移开动困难,室温拉伸强度高,延伸率低,而高温挤压得到的粗晶管材则因孪晶、多滑移系开动,协调变形性好,延伸率高,强度低。在高温拉伸和压缩变形时,随温度的升高或应变速率的下降,AM30合金管材的屈服强度及形变硬化率降低,延伸率增大。
针对镁合金的变形特点,设计并定制了一套能加热且保持相对恒温的旋转拉伸弯管机。采用该设备可以实现,加热温度范围:室温-400°C,速度范围:0-5 r/min,角度0-180°。选用两倍相对弯曲半径(弯曲半径/管外径)和90°弯曲角,以弯曲后的壁厚减薄率、截面椭圆度和回弹率作为评判标准,考察了温度、速度、管材的原始状态等工艺及材料因素对管材弯曲成形性的影响规律。结果表明,随弯曲温度的升高,管材弯曲后的截面椭圆度和释放后的回弹率均下降,当弯曲温度为200°C左右时,管壁的减薄率最小。在弯曲温度一定时,随弯曲速度的增大,管材的壁厚减薄率及截面椭圆度增大,而回弹率下降。具有细晶组织的管材在弯曲成形时,可得到较小的壁厚变化和截面形状畸变,且晶粒度的变化对弯后回弹的影响很小。管材与模具有相对滑动的接触面进行润滑处理可降低管材弯曲后的壁厚减薄率和截面椭圆度,但回弹率略有增加。实验范围内AZ31和AM30合金管材弯曲成形的最佳工艺参数为:加热温度:150-200°C,弯曲线速度8mm/s,待弯管材应具有细晶组织,管材与模具之间应做润滑处理,且在相同的工艺条件下,AM30合金管材的弯曲成形性略好于AZ31合金。
利用有限元软件MSC.Marc成功实现了AM30合金管材旋转拉伸弯曲的工艺仿真。对弯曲时处于弯曲半径内外两侧的管壁分别按压缩曲线和拉伸曲线定义材料模型。有限元模拟的结果经过了实际弯曲试验结果的验证。因此该模型可对镁合金管材的弯曲工艺设计提供成形性的综合预测。通过有限元弯曲工艺模拟预测了弯曲角度、相对弯曲半径和管材的自身规格对弯曲成形性的影响规律及应力应变的分布。结果表明:随弯曲角度的增大,管材表面的最大等效应力在30°以前迅速增大,然后趋于稳定,而最大等效塑性应变一直增加,但增加速率逐渐降低。弯曲一定角度时(90°),管材表面的等效应力与等效弹性应变分布规律类似,即在弯曲半径的内外侧与中性面附近均有峰值出现,等效塑性应变的峰值出现于弯曲半径的最外侧与最内侧,在中性面附近达到最小值。随相对弯曲半径的减小,管材的弯曲成形性迅速变差,管壁的等效塑性应变增大,可成形的最小相对弯曲半径为管材外径的1.5倍。随相对壁厚(管外径/壁厚)的增大,管材的弯曲成形性变差,可成形的最大相对壁厚值为30,相对壁厚的改变对弯曲时管壁的塑性变形量影响较小。
采用背散射电子衍射技术(EBSD)研究了AZ31和AM30合金管材在150°C弯曲前后不同变形量区域的管壁对应的微观组织,总结并提出了镁合金管材弯曲成形时的塑性变形机制。结果表明:处于弯曲半径外侧的管壁材料,在弯曲变形时主要发生拉伸变形,其变形机制以位错滑移为主,处于弯曲半径内侧的管壁,弯曲时主要发生压缩变形,变形时除发生位错滑移以外,{10-12}<10-11>拉伸孪晶是其重要的变形方式,且孪晶使管壁材料的宏观织构发生了近似90°的转变。另外,AM30合金管材的原始织构较AZ31合金的弱且分布相对分散,因此在弯曲时其变形协调性更好。
The magnesium alloy tubes are easily to be fabricated, which have high precision of size, fine microstructure, good mechanical properties, and the replacement of tubular sections to stamped components could save weight of structure in most. The magnesium alloy tubes would be the potential industrial structuresin the future. But the application of tubes generally need further second forming, such as bending, expanding, and contraction. Magnesium, with its hexagonal close packed (hcp) crystal structure, has limited slip systems and limited formability at room temperature, and then the bending method can not copy from that for the steel and aluminum tubular sections. The aim of this paper is to investigate the bendability and deformation behavior of the popular wrought Mg alloy AZ31 and AM30 tubes, and the bending mechanisms of magnesium alloy tubes. The results would provide references and consultations to the further development and applications of the Mg alloy tubes.
Two kinds of alloy AZ31 and AM30 tubes were extruded, and then the microstructure and mechanical properties of the tubes in room and high temperature were tested. The results indicate recrystallizaton following extrusion is near complete for the two kinds of alloy, and a majority of grain boundaries are high angle grain boundaries (HAGBs). A basal ring texture with the c-axes of grains perpendicular to the extrusion direction (ED) has formed. The grains of AM30 alloy tube became coarse with the raise of extrusion temperatures, and the tensile strength decreases but the elongation increases. The twinning was restricted during deformation for the fine-grain tube, and the crytal orientation is unfit for the operation of dislocation slips, so the tube has high tensile strength and low ductility. On the other hand, coarse-grain tube has low tensile strength but good ductility due to the harmony of dispersed twinning during deformation. For the tension and compression processes in high temperature, the yield strength and work hardening rate of AM30 alloy tube decrease and elongation increases with the raise of temperature and reduction of strain rate.
A warmed rotary draw bender for Mg alloy tube was designed and manufactured. It can realize warmed temperature of 20-400°C, bend velocity of 0-5r/min and bend angle of 0-180°. The effects of temperature, velocity, tube microstructure etc. on the bendability have been studied using the wall thinning, cross-section ovality and spring back as evaluation criterion in the conditions of popular used two relative bend radius and 90 degree bend angle. The results indicate both the ovality and spring back decrease with the raise of temperature, but the wall thinning is smallest at 200°C. At certain temperature, the wall thinning and ovality increase, spring back decreases with the raise of bending velocity. The fine-grain tube could obtain smaller wall thinning and ovality during bending, and the grain size has little effect on the spring back. The lubrication between die and tube can make low wall thinning and ovality, but the spring back increased slightly. In the tested parameter range, the temperature of 150-200°C, the velocity of 8mm/s, fine microstructure and lubrication are most feasible for bending of AZ31 and AM30 alloy tubes. And the bendability of AM30 alloy tube is a little better than that of AZ31 alloy tube at same bending conditons.
The finite element (FE) software MSC.Marc was used to simulate the bending process. The material in extrados and intrados of tube were defined with tension and compression curves respectively. The results of simulation were validated with actual experiments. The effects of bending angle degree, relative bending radius and tube size on the bendability were analyzed through FE simulation. The results suggest the maximum equivalent stress in tube surface increases shapely before 30 degree, then hold relative stable with the increase of bending angle degree. The maximum equivalent plastic strain increases all along with the raise of bending angle degree, but the increasing rate is reduced. At certain bending angle (90°), the distributions of equivalent stress and elastic strain are similar, namely, peak value appears both at neutral area, extrados and intrados. The peak value of equivalent plastic strain appears at the most far away of extrados and intrados, and the minimum value is at neutral area. The bendability of tube become worse rapidly and the equivalent plastic strain rises with the decrease of relative bending radius. The minimum bending radius is 1.5 times of tube outer diameter. With the raise of relative wall thickness (outer diameter/wall thickness), the bendability also become worse, and the maximum relative wall thickness is 30. The change of relative wall thickness has little effects on the plastic strain.
The microstructure of tube wall (after bending at 150°C) at different strains were analyzed through electronic backscattered diffraction (EBSD) technology. The plastic deformation mechanisms of the two kinds of alloy during bending were summarized. The results suggest the material in extrados undergoes tension and the dislocation slip is the main deformation mechanism. And the material in intrados undergoes compression; {10-12} <10-11> tension twinning is an important deformation mechanism except for dislocation slips. The texture changes approximately 90 degree due to the extension twinning. The density of texture in AM30 alloy is smaller than that of AZ31 alloy, and the crystal orientation in AM30 is a little more dispersive, so the deformation process of AM30 alloy tube is more harmonious in bending.
挤压成型了AZ31和AM30两种合金管材,并分析了它们的微观组织、室温和高温力学性能。结果表明两种合金在挤压时均发生了完全动态再结晶,形成了由大角度晶界组成的等轴晶及c轴垂直于挤压方向的丝织构,但在相同的挤压工艺下,AM30合金管材的晶粒更加细小,分布均匀。随挤压温度的升高,AM30合金管材的晶粒度增大,室温拉伸强度降低,延伸率升高;低温挤压得到的细晶管材变形时孪晶被抑制,丝织构导致基面位滑移开动困难,室温拉伸强度高,延伸率低,而高温挤压得到的粗晶管材则因孪晶、多滑移系开动,协调变形性好,延伸率高,强度低。在高温拉伸和压缩变形时,随温度的升高或应变速率的下降,AM30合金管材的屈服强度及形变硬化率降低,延伸率增大。
针对镁合金的变形特点,设计并定制了一套能加热且保持相对恒温的旋转拉伸弯管机。采用该设备可以实现,加热温度范围:室温-400°C,速度范围:0-5 r/min,角度0-180°。选用两倍相对弯曲半径(弯曲半径/管外径)和90°弯曲角,以弯曲后的壁厚减薄率、截面椭圆度和回弹率作为评判标准,考察了温度、速度、管材的原始状态等工艺及材料因素对管材弯曲成形性的影响规律。结果表明,随弯曲温度的升高,管材弯曲后的截面椭圆度和释放后的回弹率均下降,当弯曲温度为200°C左右时,管壁的减薄率最小。在弯曲温度一定时,随弯曲速度的增大,管材的壁厚减薄率及截面椭圆度增大,而回弹率下降。具有细晶组织的管材在弯曲成形时,可得到较小的壁厚变化和截面形状畸变,且晶粒度的变化对弯后回弹的影响很小。管材与模具有相对滑动的接触面进行润滑处理可降低管材弯曲后的壁厚减薄率和截面椭圆度,但回弹率略有增加。实验范围内AZ31和AM30合金管材弯曲成形的最佳工艺参数为:加热温度:150-200°C,弯曲线速度8mm/s,待弯管材应具有细晶组织,管材与模具之间应做润滑处理,且在相同的工艺条件下,AM30合金管材的弯曲成形性略好于AZ31合金。
利用有限元软件MSC.Marc成功实现了AM30合金管材旋转拉伸弯曲的工艺仿真。对弯曲时处于弯曲半径内外两侧的管壁分别按压缩曲线和拉伸曲线定义材料模型。有限元模拟的结果经过了实际弯曲试验结果的验证。因此该模型可对镁合金管材的弯曲工艺设计提供成形性的综合预测。通过有限元弯曲工艺模拟预测了弯曲角度、相对弯曲半径和管材的自身规格对弯曲成形性的影响规律及应力应变的分布。结果表明:随弯曲角度的增大,管材表面的最大等效应力在30°以前迅速增大,然后趋于稳定,而最大等效塑性应变一直增加,但增加速率逐渐降低。弯曲一定角度时(90°),管材表面的等效应力与等效弹性应变分布规律类似,即在弯曲半径的内外侧与中性面附近均有峰值出现,等效塑性应变的峰值出现于弯曲半径的最外侧与最内侧,在中性面附近达到最小值。随相对弯曲半径的减小,管材的弯曲成形性迅速变差,管壁的等效塑性应变增大,可成形的最小相对弯曲半径为管材外径的1.5倍。随相对壁厚(管外径/壁厚)的增大,管材的弯曲成形性变差,可成形的最大相对壁厚值为30,相对壁厚的改变对弯曲时管壁的塑性变形量影响较小。
采用背散射电子衍射技术(EBSD)研究了AZ31和AM30合金管材在150°C弯曲前后不同变形量区域的管壁对应的微观组织,总结并提出了镁合金管材弯曲成形时的塑性变形机制。结果表明:处于弯曲半径外侧的管壁材料,在弯曲变形时主要发生拉伸变形,其变形机制以位错滑移为主,处于弯曲半径内侧的管壁,弯曲时主要发生压缩变形,变形时除发生位错滑移以外,{10-12}<10-11>拉伸孪晶是其重要的变形方式,且孪晶使管壁材料的宏观织构发生了近似90°的转变。另外,AM30合金管材的原始织构较AZ31合金的弱且分布相对分散,因此在弯曲时其变形协调性更好。
The magnesium alloy tubes are easily to be fabricated, which have high precision of size, fine microstructure, good mechanical properties, and the replacement of tubular sections to stamped components could save weight of structure in most. The magnesium alloy tubes would be the potential industrial structuresin the future. But the application of tubes generally need further second forming, such as bending, expanding, and contraction. Magnesium, with its hexagonal close packed (hcp) crystal structure, has limited slip systems and limited formability at room temperature, and then the bending method can not copy from that for the steel and aluminum tubular sections. The aim of this paper is to investigate the bendability and deformation behavior of the popular wrought Mg alloy AZ31 and AM30 tubes, and the bending mechanisms of magnesium alloy tubes. The results would provide references and consultations to the further development and applications of the Mg alloy tubes.
Two kinds of alloy AZ31 and AM30 tubes were extruded, and then the microstructure and mechanical properties of the tubes in room and high temperature were tested. The results indicate recrystallizaton following extrusion is near complete for the two kinds of alloy, and a majority of grain boundaries are high angle grain boundaries (HAGBs). A basal ring texture with the c-axes of grains perpendicular to the extrusion direction (ED) has formed. The grains of AM30 alloy tube became coarse with the raise of extrusion temperatures, and the tensile strength decreases but the elongation increases. The twinning was restricted during deformation for the fine-grain tube, and the crytal orientation is unfit for the operation of dislocation slips, so the tube has high tensile strength and low ductility. On the other hand, coarse-grain tube has low tensile strength but good ductility due to the harmony of dispersed twinning during deformation. For the tension and compression processes in high temperature, the yield strength and work hardening rate of AM30 alloy tube decrease and elongation increases with the raise of temperature and reduction of strain rate.
A warmed rotary draw bender for Mg alloy tube was designed and manufactured. It can realize warmed temperature of 20-400°C, bend velocity of 0-5r/min and bend angle of 0-180°. The effects of temperature, velocity, tube microstructure etc. on the bendability have been studied using the wall thinning, cross-section ovality and spring back as evaluation criterion in the conditions of popular used two relative bend radius and 90 degree bend angle. The results indicate both the ovality and spring back decrease with the raise of temperature, but the wall thinning is smallest at 200°C. At certain temperature, the wall thinning and ovality increase, spring back decreases with the raise of bending velocity. The fine-grain tube could obtain smaller wall thinning and ovality during bending, and the grain size has little effect on the spring back. The lubrication between die and tube can make low wall thinning and ovality, but the spring back increased slightly. In the tested parameter range, the temperature of 150-200°C, the velocity of 8mm/s, fine microstructure and lubrication are most feasible for bending of AZ31 and AM30 alloy tubes. And the bendability of AM30 alloy tube is a little better than that of AZ31 alloy tube at same bending conditons.
The finite element (FE) software MSC.Marc was used to simulate the bending process. The material in extrados and intrados of tube were defined with tension and compression curves respectively. The results of simulation were validated with actual experiments. The effects of bending angle degree, relative bending radius and tube size on the bendability were analyzed through FE simulation. The results suggest the maximum equivalent stress in tube surface increases shapely before 30 degree, then hold relative stable with the increase of bending angle degree. The maximum equivalent plastic strain increases all along with the raise of bending angle degree, but the increasing rate is reduced. At certain bending angle (90°), the distributions of equivalent stress and elastic strain are similar, namely, peak value appears both at neutral area, extrados and intrados. The peak value of equivalent plastic strain appears at the most far away of extrados and intrados, and the minimum value is at neutral area. The bendability of tube become worse rapidly and the equivalent plastic strain rises with the decrease of relative bending radius. The minimum bending radius is 1.5 times of tube outer diameter. With the raise of relative wall thickness (outer diameter/wall thickness), the bendability also become worse, and the maximum relative wall thickness is 30. The change of relative wall thickness has little effects on the plastic strain.
The microstructure of tube wall (after bending at 150°C) at different strains were analyzed through electronic backscattered diffraction (EBSD) technology. The plastic deformation mechanisms of the two kinds of alloy during bending were summarized. The results suggest the material in extrados undergoes tension and the dislocation slip is the main deformation mechanism. And the material in intrados undergoes compression; {10-12} <10-11> tension twinning is an important deformation mechanism except for dislocation slips. The texture changes approximately 90 degree due to the extension twinning. The density of texture in AM30 alloy is smaller than that of AZ31 alloy, and the crystal orientation in AM30 is a little more dispersive, so the deformation process of AM30 alloy tube is more harmonious in bending.
引文
[1]К.Н.,马图哈.材料科学与技术丛书—非铁合金的结构与性能.丁道云等译.北京:科学出版社, 1999
[2] Norsk Hydro Databank. Norsk Hydro Research Center Porsgrunn,1996
[3] Nabarro, F.R.N., Quintanilha, A.J. Dislocation in solids. Volume 2, Dislocation in crystals. Amsterdam, New York, Oxford: North-holland Publishing Company: 1979
[4] Siethoff, H., Ahlborn, K. Steady-state Deformation of The HCP Metals at High and Intermediate Temperatures. Z. Metallkd. 1985, 76(9): 627-634
[5]张丝雨.最新金属材料牌号、性能、用途及中外牌号对照速用速查手册.北京:中国科技文化出版社. 2005.
[6]美国金属学会.金属手册(第九版)第二卷.北京:机械工业出版社. 1994: 689.
[7] Froes, F.H., Eliezer, D., Aghion, E. The science, technology, and applications of magnesium. JOM. 1998, 50(9): 30-34.
[8]刘兵.加强技术创新为经济结构调整提供强大动力.材料热处理学报. 2001(22增刊): 1-7.
[9]曾小勤,王渠东,吕宜振等.镁合金应用进展.铸造, 1998 (11): 39-43.
[10]王渠东,丁文江.镁合金及其成形技术的最新发展. 21世纪材料成形加工技术与科学. 2004(3): 56-73.
[11] Brown, R.E. 53rd Annual Word Magnesium Conference. Light Metal Age. August, 1996: 50-60.
[12] Aghion, E., Bronfin, B. Magnesium alloys development towards the 21st century.Mater Sci Forum. 2000(350-351): 19-29.
[13] Polmear, I.J. Light Metals. Metallurgy of the light Metals. 3rd ed. Edward Arnold, London, 1995
[14] Das, S.K., Chang, C.F. Magnesium Alloys and their Applications. Oberursel, FRG. DGM Information sgesellschaft. 1992: 487.
[15]黄少东,唐全波,赵祖德等.用镁合金促进兵器装备轻量化.金属成形工艺. 2002, 20(5): 8-10.
[16] Froes, F.H., Eliezer, D., Aghion, E. The science technology and applications of magnesium. JOM. 1998(9): 30-33.
[17] Luo, A.A., Renaud, J., Plourde, J. Magnesium Castings in the Automotive Industry - Recent Developments and Future Challenges. International Symposium on Recent Advances in the Light Metals Industries. The Metallurgical Society of CIM. Canada. 1995: 329-339.
[18] Busk, R.S. Magnesium Products Design. New York. Marcel Dekker INC. 1987: 248-448.
[19] Luo, A.A., Sachdev, A.K. Wrought Magnesium Research for Automotive Applications. Magnesium Technology. TMS, Warrendale, PA. 2006: 333-339.
[20] Luo, A.A. Wrought Magnesium Alloys and Manufacturing Processes for Automotive Applications. SAE Technical Paper 2005-01-0734. Detroit, MI. 2005.
[21] Powell, B.R., Luo, A.A., Rezhets, V., etc. Development of Creep- Resistant Magnesium Alloys for Powertrain Applications: Part 1 of 2. SAE Technical Paper 2001-01-0422. Detroit, MI. 2001.
[22] Asm International. Magnesium And Magnesium Alloy. OH, Metal Park. 1999(1).
[23] Koike, J., Kobayashi, T., Mukai, T., etc. The activity of non-basal slip system and dynamic recovery at room temperature in fine-grained AZ31B magnesium alloys. Acta Materialia. 2003(51): 2055-2065.
[24] Von Mises, R., Angew, Z. Math. Mech. 1928(6): 85.
[25] Roberts, C.S. Magnesium and Its alloys. John Wiley & Sons, Inc. New York.1960.
[26] Yoo, M.H. Slip, twinning, and fracture in hexagonal close-packed metals. Metallurgical Transactions A. 1981(12): 409-418.
[27] Couret, A., Caillard, D. Prismatic slip in beryllium: I. The controlling mechanism at the peak temperature. Philosophical Magazine A. 1989(59): 783-800.
[28] Goo E., Kee, T.P. Application of the von Mises criterion to deformation twinning. Scipta Materialia. 1989(23): 1053-1056.
[29] Christian, J.W., Mahajan, S. Deformation twinning. Progress in Materials Science. 1995(39): 1-15.
[30] Wu, L., Jain, A., Brown, D.W., etc. Twinning-detwinning behavior during the strain controlled low-cycle fatigue testing of a wrought magnesium alloy ZK60A. Acta Materialia. 2008, 56 (4): 688-695.
[31] Avedesian, M.M., Baker,H. Magnesium and Magnesium alloys. ASM Specialty Handbook. The Materials Information Society. OH: Metal Park. 1999(1).
[32]陈振华.变形镁合金.北京:化学工业出版社. 2005.
[33] Klimanek, P., Potzsch, A. Microstructure evolution under compressive plastic deformation of magnesium at different temperatures and strain rates. Meterials Sci. Eng. A. 2002(324): 145-150.
[34] Chandrasekaran, M., Ming, Y., John, S. Effect of materials and temperature on the forward extrusion of magnesium alloys. Materials Science and Engineering A. 2004(381): 308-319.
[35]林金保,王渠东,陈勇军.镁合金塑性成形技术研究进展.轻合金. 2006(10): 76-80.
[36] Rokhlin, L.L. Advanced Magnesium Alloys with Rare-earth Metal Additions. Advanced Light Alloys and Composites. 1998: 443-448.
[37] Galiyev, A., Kaibyshev, R., Gottstein, G. Correlation of plastic deformation and dynamic recrystallization in magnesium alloy ZK60. Acta Materialia. 2001, 49(7): 1199-1207.
[38] Skubisz, P., Sińczak, J., Bednarek, S. Forgeability of Mg–Al–Zn magnesium alloys in hot and warm closed die forging. Journal of Materials Processing Technology. 2006, 177(1-3): 210-213.
[39] Garcés, G., Müller, A., O?orbe, E., etc. Effect of hot forging on the microstructure and mechanical properties of Mg-Zn-Y alloy. Journal of Materials Processing Technology. 2008, 206(1-3): 99-105.
[40] Chaudhury, P.K., Agnew, S.R. Forging of Magnesium Alloys ASM Handbook. Volume 14A, Metalworking: Bulk Forming. 2005 ASM International. Materials Park: 318.
[41] Liu, J., Cui, Z.S. Hot forging process design and parameters determination of magnesiumalloy AZ31B spur bevel gear. Journal of Materials Processing Technology. 2009, 209(18-19): 5871-5880.
[42] Huang, X.S., Suzuki, K., Saito, N. Enhancement of stretch formability of Mg-3Al-1Zn alloy sheet using hot rolling at high temperatures up to 823 K and subsequent warm rolling. Scripta Materialia. 2009, 61(4): 445-448.
[43] Kelley, E.W., Hosford, W.F. The deformation characteristics of textured magnesium. Transactions of the metallurgical society of AIME. 1968(242): 654-661.
[44] Park, S.S., You, B.S., Yoon, D.J. Effect of the extrusion conditions on the texture and mechanical properties of indirect-extruded Mg-3Al-1Zn alloy. Journal of Materials Processing Technology. 2009, 209(18-19): 5940-5943.
[45] Chang, L.L., Wang, Y.N., Zhao, X., etc. Grain size and texture effect on compression behavior of hot-extruded Mg-3Al-1Zn alloys at room temperature. Materials Characterization. 2009, 60(9): 991-994.
[46] Singh, R.K., Singh, A.K., Eswara, N. Texture and mechanical property anisotropy in an Al-Mg-Si-Cu alloy. Materials Science and Engineering A. 2000, 277(1-2): 114-122.
[47] Hilpert, M., Wagner, L. Effect of Mechanical Surface Treatments and Environment on Fatigue of Wrought Magnesium alloys. Magnesium Alloys and their Applications. 2000: 463-468.
[48] Zhang, P., Lindemann, J. Influence of Shot Peening on High Cycle Fatigue Properties of the High-Strength Wrought Magnesium Alloy AZ80. Scripta Mater. 2005(52): 485-490.
[49]温彤,丰慧珍,艾百胜.管材绕弯变形的理论与实验分析.重庆大学学报(自然科学版). 2006(12): 8-12.
[50]邵靖利.推制工艺对推制弯头几何形状的影响. Machinist Metal Forming. 2007(06): 78-80.
[51] Zhiren, H., Lingyun, Z. Spingback prediction method during formation with press bending. Journal of Liaoning Technical University (Natural Science). 2008, 04.
[52]李大永,蒋劲茂,彭颖红,尹纪龙.辊弯成形过程仿真与参数优化.系统仿真学报.2007(04): 893-896.
[53]陈明微.旋转拉伸弯管法.金属成形工艺. 1995, 13(3): 1-7.
[54] Zhan, M., Yang, H., Jiang, Z.Q., etc. A study on a 3D FE simulation method of the NC bending process of thin-walled tube. Journal of Materials Processing Technology. 2002(129): 273-276.
[55]田福祥,王珍.管件弯曲加工新技术.锻压机械. 2002(3): 32-34.
[56] Yang, H., Lin, Y. Wrinkling analysis for forming limit of tube bending processes. Journal of Materials Processing Technology. 2004(152): 363-369.
[57] Li, H., Yang, H., Zhan, M., etc. The interactive effects of wrinkling and other defects in thin-walled tube NC bending process. Journal of Materials Processing Technology. 2007(187-188): 502-507.
[58] Al-Qureshi, H.A., Russo, A. Spring-back and residual stresses in bending of thin-walled aluminum tubes. Materials and Design. 2002(23): 217-222.
[59] Mori, S., Manabe, K-I., Nishimura, H. Experimental analysis of the flattening of the cross-section, the springback and the bending moment of clad tubes in uniform bending. Journal of Materials Processing Technology. 1997(66): 270-276.
[60] Bai, Y., Ragnar, T., Igland, T. Tube collapse under combined external pressure, tension and bending. Marine Structure. 1997(10): 389-410.
[61]李恒.薄壁管数控弯曲成形过程失稳起皱及成形极限的研究[硕士论文].西安:西北工业大学. 2004.
[62] Yang, H., Lin, Y. Wrinkling analysis for forming limit of tube bending processes. Journal of Processing Technology. 2004(152): 363-369.
[63]胡忠,夏福清.中频感应局部加热弯管的回弹理论分析和试验研究.固体力学学报. 1998, 19(4): 329-335.
[64]胡忠.中频感应局部加热弯管回弹的研究.应用力学学报. 1999, 16(2): 81-88.
[65]刘志刚,李祖光,林尉.弯管回弹问题探讨研究.电站系统工程. 1999, 15 (3): 60-65.
[66] Pan, K., Stelson, K.A. On the plastic deformation of a tube during bending. Journal ofEngineering for Industry Transactions of the ASME. 1995(117): 494-499.
[67] Ju, G.T., Kyriakids, S. Bifurcation and localization instabilities in cylindricall shells under bending-Ⅱpredications. Int. J. Solids Struct. 1992, 29(9): 1143-1171.
[68] Kyriakide, S., Ju, G.T. Bifurcation and localization instabilities in cylindricalll shells under bending-Ⅰ. Experiments. Int. J. Solids Struct. 1992, 29(9): 1117-1142.
[69] Paulsen, F., Welo, T., Sovik, O.P. A design method for rectangular hollow sections in bending. Journal of Materials Processing Technology. 2001(113): 609-704.
[70] Paulsen, F., Welo, T. Cross-sectional deformations of rectangular hollow sections in bending: PartⅡ-analytical models. International Journal of Mechanical Science. 2001(43): 131-152.
[71]吉田正敏,藤原昭文.アルミ中空矩形断面形材の曲げ加工におけるしわ,ひずみ量予测.塑性と加工. 1997, 38(440): 803-808.
[72]吉田正敏,藤原昭文.アルミニウム中空矩形断面形材の曲げ加工におけるしわ发生限界曲げ半径の予测.塑性と加工. 2000(41): 74-78.
[73] Endow, J., Murofa, T.圆管横截面在均匀弯曲时的变扁.世界塑性加工最新技术译文集[C].中国机械工程学会、中国金属学会轧钢学会译.机械工程出版社. 1987: 461-465.
[74] Marcal, P.V., King, I.D. Elastic-plastic Analysis of Two-dimensional Stress System by the F inite Element Method. Int. J. Mech. Sci. 1967(9):143-155.
[75] Yamada, Y., Yoshimura, N., Sakurai, T. Plastic Stress-strain Matrix and its Application for the Solutions of Elastic-plastic Problems by the Finite Element Method. Int. J. Mech. Sci. 1967(10): 343-354.
[76] Trana, K. Finite element simulation of the tube hydroforming process-bending, performing and hydroforming. Journal of Materials Processing Technology. 2002(127): 401-408.
[77]胡福泰.异型管材与型材无模弯曲工艺理论与实验研究[博士学位论文].东北重型机械学院. 1995
[78] Yang, J.B., Jeon, B.H., Oh, S.I. The tube bending Technology of a Hydroforming Process for An Automotive Part. J. of Mats. Proc. Tech. 2001(111): 175-181.
[79] Han, L.H., He, S.Y., Wang, Y.P., etc. Limit Moment of Local Wall Thinning in Pipe UnderBending. Int. J. of Press. Vess. Piping. 1999: 539-542.
[80] ASM Metals Handbook. Forming and Forging. Vol. 14. Materials Park, Ohio: ASM International. 2000.
[81]张君.加热弯管工艺计算机数值模拟[硕士学位论文].西北工业大学. 2001.
[82] ASM Metals Handbook. Forming of Copper and Copper Alloys. Vol. 14. Materials Park, Ohio: ASM International. 1993.
[83] Luo, A.A., Sachdev, A.K. Development of a moderate temperature bending process for magnesium alloy extrusions. Materials Science Forum. 2005(488-489): 477-482.
[84] Luo, A.A., Sachdev, A.K. Bending and Hydroforming of Aluminum and Magnesium. Alloy Tubes for Automotive Applications. Proceedings of the 3rd North American, Hydroforming Conference. Novi. MI. 2005(26-28): 1-13.
[85] Luo, A.A., Sachdev, A.K. Bendability and Microstructure of Magnesium Alloy Tubes at Room and Elevated Temperatures. Magnesium Technology 2005. TMS, Warrendale, PA. 2005: 145-148.
[86] Takahashi, H., Oishi, Y., Wakamatsu, K., etc. Tensile Properties and Bending Formability of Drawn Magnesium Alloy Pipes. Materials Science Forum. 2003(419-422): 345.
[1] ASM Specialty Handbook. Magnesium and Magnesium alloys. Materials Park, Ohio: ASM International. 2000.
[2]王迎新. Mg-Al合金晶粒细化、热变形行为及加工工艺的研究[博士论文].上海:上海交通大学. 2006.
[3]刘满平. Mg-Al-Ca合金微观组织、力学性能和蠕变变形行为[博士论文].上海:上海交通大学. 2004.
[4]周海涛. Mg-6Al-1Zn合金高温塑性变形行为及管材热挤压研究[博士论文].上海:上海交通大学. 2004.
[5]中国标准出版社第二编辑室编.金属力学性能及工艺性能试验方法.北京:中国标准出版社. 2001.
[6]吴文云,张平,姚寿山,等.全自动数控液压热弯机.外观设计专利,专利号ZL 2007 3 0086596.2.
[7]吴文云,张平,姚寿山,等.用于热弯的数控弯管机模具.实用新型专利.专利号ZL 2007 2 0198534.5.
[8]艾治勇.弯管的弯曲成形分析及其力学特性研究[硕士论文].上海:上海交通大学. 2005.
[9]电子背散射分析方法通则,GB/T19501-2004.
[10]陈勇军.往复挤压镁合金的组织结构与力学性能研究[博士论文].上海:上海交通大学,2007
[11] Mishra, R.K., Gupta, A.K., Rao, P.R., etc. Influence of cerium on the texture and ductility of magnesium extrusions. Scr. Mater. 2008(59): 562-565.
[1] Wang, Y., Jin, L., Zeng, X. Microstructure and Bendability of AM60 and AZ61 Magnesium Alloy Tubes. Magnesium Technology. 2008: 165-170.
[2]余永宁.金属学原理.北京:冶金工业出版社. 2000.
[3]陈振华.变形镁合金.北京:化学工业出版社. 2005.
[4] Chandrasekaran, M., Ming, Y., John, S. Effect of materials and temperature on the forward extrusion of magnesium alloys. Materials Science and Engineering A. 2004(381): 308-319.
[5]王迎新. Mg-Al合金晶粒细化、热变形行为及加工工艺的研究[博士论文].上海:上海交通大学. 2006.
[6] Watanabe, H., Tsutsui, H., Mukai, T. Grain size control of commercial wrought Mg-Al-Zn alloys utilizing dynamic recrystallization. Mater Trans JIM. 2001, 42 (7): 1200-1205.
[7] Humpreys, F.J., Hatherly, M. Recrystallization and Related Annealing Phinomena. Printed and bound in Great Britain by Galliard (printers) Ltd. 1995: 363.
[8] Jin, L., Lin, D.L., Mao, D.L., etc. Materials Science and Engineering A. 2006(423): 247-252.
[9] Reed-Hill, R.E., Robertson, W.D. Aditional modes of deformation twinning in magnesium. Acta Metall. 1957(5): 717-727.
[10] Jiang, L., Jonas, J.J., Mishra, R.K., etc. Twinning and texture development in two Mg alloys subjected to loading along three different strain paths. Acta materialia. 2007, 55(11): 3899-3910.
[11] Barnett, M.R. A rationale for the strong dependence of mechanical twinning on grain size. Scripta Materialia. 2008(59): 696-698.
[12] Chino, Y., Kimura, K., Hakamada, M., etc. Mechanical anisotropy due to twinning in an extruded AZ31 Mg alloy. Meterials Sci. Eng. A. 2008(485): 311-317.
[13] Bohlen, J., Chmelík, F., Kaiser, F. Kovo. Mater. 2002(40): 290-297.
[14] Roberts, C.S. Magnesium and Its alloys. John Wiley & Sons, Inc. New York. 1960.
[15]艾治勇.弯管的弯曲成形分析及其力学特性研究[硕士论文].上海:上海交通大学. 2005.
[16]杨觉先.金属塑性变形物理基础.北京:冶金工业出版社. 1988.
[17]陈振华,夏伟军,严红革,等.镁合金材料的塑性变形理论及其技术.化工进展. 2004,23(2): 127-131.
[18] Ion, S.E., Homphreys, F.J., Whice, S.H. Dynamic recrystallization and the development of microstructure during the high temperature deformation of magnesium. Acta Mater. 1982(30): 1909-1919.
[19] Couret, A., Caillard, D. An in-situ study of prismatic glide in magnesium- I. The rate controlling mechanism. Acta Metallurgica Materialia. 1985, 33(8): 1447-1454.
[20] Watanabe, H., Tsutsui, H., Mukai, T. Grain size control of commercial wrought Mg-Al-Zn alloys utilizing dynamic recrystallization. Mater Trans JIM. 2001, 42 (7): 1200-1205.
[21] Klimanek, P., Potzsch, A. Microstructure evolution under compressive plastic deformation of magnesium at different temperatures and strain rates. Meterials Sci. Eng. A. 2002(324): 145-150.
[22] Yoo, M.H., Lee, J.K. Deformation twinning in h.c.p. metals and alloys. Philosophical Magazine A. 1991(63): 987-1000.
[23] Goo, E., Kee, T.P. Application of the von Mises criterion to deformation twinning. Scipta Materialia. 1989(23): 1053-1056.
[24] Asm International. Magnesium And Magnesium Alloy. OH, Metal Park. 1999, 1.
[1]余琨,黎文献,王日初.镁合金塑性变形机制.中国有色金属学报. 2005,15(7): 1081-1086.
[2] Li, H., Yang, H. Trans. Nonferrous Met. Soc. China. 2006(16): 613-623.
[3] Tang, N.C. Plastic-deformation analysis in tube bending, Pressure vessels and piping. 2000(77): 751-759.
[4] Wu, W.Y., Zhang, P., Zeng, X.Q., etc. Bendability of the wrought magnesium alloy AM30 tubes using a rotary draw bender. Mater. Sci. Eng. A. 2008(486): 596-601.
[5] Galiyev, A., Kaibyshev, R., GTottstein, G. Correlation of plastic deformation and dynamic recrystallization in magnesium alloy ZK60. Acta Materialia. 2001(49): 1199-1207.
[6] Mori, S., Manabe, K.-I. Nishimura, H., etc. Experimental analysis of the flattening of the cross-section, the springback and the bending moment of clad tubes in uniform bending. Journal of Materials Processing Technology. 1997(66): 270-276.
[7] Bai, Y., Ragnar, T., Moan, I.T. Tube collapse under combined external pressure, tension andbending. Marine Structure. 1997(10): 389-410.
[8] Al-Qureshi, H.A. Elastic-plastic analysis of tube bending. Machine tools & manufacture. 1999(39): 87-104.
[9]艾治勇.弯管的弯曲成形分析及其力学特性研究[硕士论文].上海:上海交通大学. 2005.
[10] Zhan, M., Yang, H., Huang, L., etc. Spirngback analysis of numerical control bending of thin-walled tube using numerical-analytic method. Journal of Materials Processing Technology. 2006(177): 197-201.
[11] Al-Qureshi, H.A., Russo, A. Spring-back and residual stresses in bending of thin-walled aluminum tubes. Materials & Design. 2002(23): 217-222.
[12]胡忠,夏福清.中频感应局部加热弯管的回弹理论分析和试验研究.固体力学学报. 1998, 19(4): 329-335.
[13] Wang, J.T., Yin, D.L., Liu, J.Q., etc. Effect of grain size on mechanical property of Mg-3Al-1Zn alloy. Scripta Mater. 2008(59): 63-66.
[14] Watanabe, H., Tsutsui, H., Mukai, T. Grain size control of commercial wrought Mg-Al-Zn alloys utilizing dynamic recrystallization. Mater Trans JIM. 2001, 42 (7): 1200-1205.
[1] Gao, L., Strano, M. FEM analysis of tube pre-bending and hydroforming. Journal of Materials Processing Technology. 2004(151): 294-297.
[2] Trana, K. Finite element simulation of the tube hydroforming process-bending, performing and hydroforming. Journal of Materials Processing Technology. 2002(127): 401-408.
[3]张华.管材弯曲成形过程数值模拟的研究[博士学位论文].重庆:重庆大学. 1999.
[4] Lang, L., Yuan, S., Wang, X., etc. A study on numerical simulation of hydroforming of aluminum alloy tube. Journal of Materials Processing Technology. 2004(146): 377-388.
[5] MARC Reference manual. Volume A. 2005.
[6] Asm International. Magnesium and Magnesium Alloy. OH, Metal Park. 1999, 1.
[7]刘鸿文,材料力学(第四版).高等教育出版社.北京: 2005.
[8]陈火红. MSC.Marc / Mentat 2003基础与应用实例.北京:科学出版社. 2004.
[9] Yang, J-B., Jeon, B-H., Oh, S.-I. The tube bending technology of a hydroforming process for an automotive part. Journal of Materials Processing Technology. 2001(111): 175-181.
[10] Li, H., Yang, H., Zhan, M., etc. The interactive effects of wrinkling and other defects in thin-walled tube NC bending process. Journal of Materials Processing Technology. 2007(187-188): 502-507.
[11] Al-Qureshi, H.A., Russo, A. Spring-back and residual stresses in bending of thin-walled aluminum tubes. Materials and Design. 2002(23): 217-222.
[12] Trana, K. Finite element simulation of the tube hydroforming process-bending, performing and hydroforming. Journal of Materials Processing Technology. 2002(127): 401-408.
[13] Yang, H., Lin, Y. Wrinkling analysis for forming limit of tube bending processes. Journal of Materials Processing Technology. 2004(152): 363-369.
[14] Bai, Y., Ragnar, T., Moan, I.T. Tube collapse under combined external pressure, tension and bending. Marine Structure. 1997(10): 389-410.
[15] Mori, S., Manabe, K.-I., Nishimura, H. Experimental analysis of the flattening of the cross section, the springback and the bending moment of clad tubes in uniform bending. Journal of Materials Processing Technology. 1997(66): 270-276.
[1] Yoo, M.H. Slip, twinning, and fracture in hexagonal close-packed metals. Metallurgical Transactions A. 1981(12): 409-418.
[2] Wang, Y.N., Huang, J.C. Texture analysis in hexagonal materials. Materials Chemistry and Physics. 2003(81): 11-26.
[3] Jin, L., Wu, W.Y., Mishra, R.K., etc. Deformation Mechanisms in AZ31 Magnesium Alloy Tube Bending. Magnesium Technology (TMS). 2009: 429-434.
[4] Takuda, H., Fujimoto, H., Hatta, N. Modelling on flow stress of Mg-Al-Zn alloys at elevated temperatures. Journal of Materials Processing Technology. 1998(80-81): 513-516.
[5] Christian, J.W., Mahajan, S. Deformation twinning. Progress in Materials Science. 1995(39): 1-15.
[6] Buchanan, E.R., Reed-Hill, R.E. Stress-strain behavior of magnesium single crystals deformed by rotational slip. Transactions of the Metallurgical Society of AIME. 1969, 245(9): 1929-1935.
[7] Koike, J., Kobayashi, T., Mukai, T., etc. The activity of non-basal slip system and dynamic recovery at room temperature in fine-grained AZ31B magnesium alloys. Acta Materialia. 2003(51): 2055-2065.
[8] Reed-Hill, R.E., Robertson, W.D. Aditional modes of deformation twinning in magnesium. Acta Metall. 1957(5): 717-727.
[9] Couret, A., Caillard, D. Prismatic slip in beryllium I. The controlling mechanism at the peak temperature. Philosophical Magazine A. 1989(59): 783-800.
[10] Flynn, P.W., Mote, J., Dorn, J.E. On the thermally activated mechanism of prismatic slip in magnesium single crystals. Trans. TMS-AIME. 1961(221): 1148-1154.
[2] Norsk Hydro Databank. Norsk Hydro Research Center Porsgrunn,1996
[3] Nabarro, F.R.N., Quintanilha, A.J. Dislocation in solids. Volume 2, Dislocation in crystals. Amsterdam, New York, Oxford: North-holland Publishing Company: 1979
[4] Siethoff, H., Ahlborn, K. Steady-state Deformation of The HCP Metals at High and Intermediate Temperatures. Z. Metallkd. 1985, 76(9): 627-634
[5]张丝雨.最新金属材料牌号、性能、用途及中外牌号对照速用速查手册.北京:中国科技文化出版社. 2005.
[6]美国金属学会.金属手册(第九版)第二卷.北京:机械工业出版社. 1994: 689.
[7] Froes, F.H., Eliezer, D., Aghion, E. The science, technology, and applications of magnesium. JOM. 1998, 50(9): 30-34.
[8]刘兵.加强技术创新为经济结构调整提供强大动力.材料热处理学报. 2001(22增刊): 1-7.
[9]曾小勤,王渠东,吕宜振等.镁合金应用进展.铸造, 1998 (11): 39-43.
[10]王渠东,丁文江.镁合金及其成形技术的最新发展. 21世纪材料成形加工技术与科学. 2004(3): 56-73.
[11] Brown, R.E. 53rd Annual Word Magnesium Conference. Light Metal Age. August, 1996: 50-60.
[12] Aghion, E., Bronfin, B. Magnesium alloys development towards the 21st century.Mater Sci Forum. 2000(350-351): 19-29.
[13] Polmear, I.J. Light Metals. Metallurgy of the light Metals. 3rd ed. Edward Arnold, London, 1995
[14] Das, S.K., Chang, C.F. Magnesium Alloys and their Applications. Oberursel, FRG. DGM Information sgesellschaft. 1992: 487.
[15]黄少东,唐全波,赵祖德等.用镁合金促进兵器装备轻量化.金属成形工艺. 2002, 20(5): 8-10.
[16] Froes, F.H., Eliezer, D., Aghion, E. The science technology and applications of magnesium. JOM. 1998(9): 30-33.
[17] Luo, A.A., Renaud, J., Plourde, J. Magnesium Castings in the Automotive Industry - Recent Developments and Future Challenges. International Symposium on Recent Advances in the Light Metals Industries. The Metallurgical Society of CIM. Canada. 1995: 329-339.
[18] Busk, R.S. Magnesium Products Design. New York. Marcel Dekker INC. 1987: 248-448.
[19] Luo, A.A., Sachdev, A.K. Wrought Magnesium Research for Automotive Applications. Magnesium Technology. TMS, Warrendale, PA. 2006: 333-339.
[20] Luo, A.A. Wrought Magnesium Alloys and Manufacturing Processes for Automotive Applications. SAE Technical Paper 2005-01-0734. Detroit, MI. 2005.
[21] Powell, B.R., Luo, A.A., Rezhets, V., etc. Development of Creep- Resistant Magnesium Alloys for Powertrain Applications: Part 1 of 2. SAE Technical Paper 2001-01-0422. Detroit, MI. 2001.
[22] Asm International. Magnesium And Magnesium Alloy. OH, Metal Park. 1999(1).
[23] Koike, J., Kobayashi, T., Mukai, T., etc. The activity of non-basal slip system and dynamic recovery at room temperature in fine-grained AZ31B magnesium alloys. Acta Materialia. 2003(51): 2055-2065.
[24] Von Mises, R., Angew, Z. Math. Mech. 1928(6): 85.
[25] Roberts, C.S. Magnesium and Its alloys. John Wiley & Sons, Inc. New York.1960.
[26] Yoo, M.H. Slip, twinning, and fracture in hexagonal close-packed metals. Metallurgical Transactions A. 1981(12): 409-418.
[27] Couret, A., Caillard, D. Prismatic slip in beryllium: I. The controlling mechanism at the peak temperature. Philosophical Magazine A. 1989(59): 783-800.
[28] Goo E., Kee, T.P. Application of the von Mises criterion to deformation twinning. Scipta Materialia. 1989(23): 1053-1056.
[29] Christian, J.W., Mahajan, S. Deformation twinning. Progress in Materials Science. 1995(39): 1-15.
[30] Wu, L., Jain, A., Brown, D.W., etc. Twinning-detwinning behavior during the strain controlled low-cycle fatigue testing of a wrought magnesium alloy ZK60A. Acta Materialia. 2008, 56 (4): 688-695.
[31] Avedesian, M.M., Baker,H. Magnesium and Magnesium alloys. ASM Specialty Handbook. The Materials Information Society. OH: Metal Park. 1999(1).
[32]陈振华.变形镁合金.北京:化学工业出版社. 2005.
[33] Klimanek, P., Potzsch, A. Microstructure evolution under compressive plastic deformation of magnesium at different temperatures and strain rates. Meterials Sci. Eng. A. 2002(324): 145-150.
[34] Chandrasekaran, M., Ming, Y., John, S. Effect of materials and temperature on the forward extrusion of magnesium alloys. Materials Science and Engineering A. 2004(381): 308-319.
[35]林金保,王渠东,陈勇军.镁合金塑性成形技术研究进展.轻合金. 2006(10): 76-80.
[36] Rokhlin, L.L. Advanced Magnesium Alloys with Rare-earth Metal Additions. Advanced Light Alloys and Composites. 1998: 443-448.
[37] Galiyev, A., Kaibyshev, R., Gottstein, G. Correlation of plastic deformation and dynamic recrystallization in magnesium alloy ZK60. Acta Materialia. 2001, 49(7): 1199-1207.
[38] Skubisz, P., Sińczak, J., Bednarek, S. Forgeability of Mg–Al–Zn magnesium alloys in hot and warm closed die forging. Journal of Materials Processing Technology. 2006, 177(1-3): 210-213.
[39] Garcés, G., Müller, A., O?orbe, E., etc. Effect of hot forging on the microstructure and mechanical properties of Mg-Zn-Y alloy. Journal of Materials Processing Technology. 2008, 206(1-3): 99-105.
[40] Chaudhury, P.K., Agnew, S.R. Forging of Magnesium Alloys ASM Handbook. Volume 14A, Metalworking: Bulk Forming. 2005 ASM International. Materials Park: 318.
[41] Liu, J., Cui, Z.S. Hot forging process design and parameters determination of magnesiumalloy AZ31B spur bevel gear. Journal of Materials Processing Technology. 2009, 209(18-19): 5871-5880.
[42] Huang, X.S., Suzuki, K., Saito, N. Enhancement of stretch formability of Mg-3Al-1Zn alloy sheet using hot rolling at high temperatures up to 823 K and subsequent warm rolling. Scripta Materialia. 2009, 61(4): 445-448.
[43] Kelley, E.W., Hosford, W.F. The deformation characteristics of textured magnesium. Transactions of the metallurgical society of AIME. 1968(242): 654-661.
[44] Park, S.S., You, B.S., Yoon, D.J. Effect of the extrusion conditions on the texture and mechanical properties of indirect-extruded Mg-3Al-1Zn alloy. Journal of Materials Processing Technology. 2009, 209(18-19): 5940-5943.
[45] Chang, L.L., Wang, Y.N., Zhao, X., etc. Grain size and texture effect on compression behavior of hot-extruded Mg-3Al-1Zn alloys at room temperature. Materials Characterization. 2009, 60(9): 991-994.
[46] Singh, R.K., Singh, A.K., Eswara, N. Texture and mechanical property anisotropy in an Al-Mg-Si-Cu alloy. Materials Science and Engineering A. 2000, 277(1-2): 114-122.
[47] Hilpert, M., Wagner, L. Effect of Mechanical Surface Treatments and Environment on Fatigue of Wrought Magnesium alloys. Magnesium Alloys and their Applications. 2000: 463-468.
[48] Zhang, P., Lindemann, J. Influence of Shot Peening on High Cycle Fatigue Properties of the High-Strength Wrought Magnesium Alloy AZ80. Scripta Mater. 2005(52): 485-490.
[49]温彤,丰慧珍,艾百胜.管材绕弯变形的理论与实验分析.重庆大学学报(自然科学版). 2006(12): 8-12.
[50]邵靖利.推制工艺对推制弯头几何形状的影响. Machinist Metal Forming. 2007(06): 78-80.
[51] Zhiren, H., Lingyun, Z. Spingback prediction method during formation with press bending. Journal of Liaoning Technical University (Natural Science). 2008, 04.
[52]李大永,蒋劲茂,彭颖红,尹纪龙.辊弯成形过程仿真与参数优化.系统仿真学报.2007(04): 893-896.
[53]陈明微.旋转拉伸弯管法.金属成形工艺. 1995, 13(3): 1-7.
[54] Zhan, M., Yang, H., Jiang, Z.Q., etc. A study on a 3D FE simulation method of the NC bending process of thin-walled tube. Journal of Materials Processing Technology. 2002(129): 273-276.
[55]田福祥,王珍.管件弯曲加工新技术.锻压机械. 2002(3): 32-34.
[56] Yang, H., Lin, Y. Wrinkling analysis for forming limit of tube bending processes. Journal of Materials Processing Technology. 2004(152): 363-369.
[57] Li, H., Yang, H., Zhan, M., etc. The interactive effects of wrinkling and other defects in thin-walled tube NC bending process. Journal of Materials Processing Technology. 2007(187-188): 502-507.
[58] Al-Qureshi, H.A., Russo, A. Spring-back and residual stresses in bending of thin-walled aluminum tubes. Materials and Design. 2002(23): 217-222.
[59] Mori, S., Manabe, K-I., Nishimura, H. Experimental analysis of the flattening of the cross-section, the springback and the bending moment of clad tubes in uniform bending. Journal of Materials Processing Technology. 1997(66): 270-276.
[60] Bai, Y., Ragnar, T., Igland, T. Tube collapse under combined external pressure, tension and bending. Marine Structure. 1997(10): 389-410.
[61]李恒.薄壁管数控弯曲成形过程失稳起皱及成形极限的研究[硕士论文].西安:西北工业大学. 2004.
[62] Yang, H., Lin, Y. Wrinkling analysis for forming limit of tube bending processes. Journal of Processing Technology. 2004(152): 363-369.
[63]胡忠,夏福清.中频感应局部加热弯管的回弹理论分析和试验研究.固体力学学报. 1998, 19(4): 329-335.
[64]胡忠.中频感应局部加热弯管回弹的研究.应用力学学报. 1999, 16(2): 81-88.
[65]刘志刚,李祖光,林尉.弯管回弹问题探讨研究.电站系统工程. 1999, 15 (3): 60-65.
[66] Pan, K., Stelson, K.A. On the plastic deformation of a tube during bending. Journal ofEngineering for Industry Transactions of the ASME. 1995(117): 494-499.
[67] Ju, G.T., Kyriakids, S. Bifurcation and localization instabilities in cylindricall shells under bending-Ⅱpredications. Int. J. Solids Struct. 1992, 29(9): 1143-1171.
[68] Kyriakide, S., Ju, G.T. Bifurcation and localization instabilities in cylindricalll shells under bending-Ⅰ. Experiments. Int. J. Solids Struct. 1992, 29(9): 1117-1142.
[69] Paulsen, F., Welo, T., Sovik, O.P. A design method for rectangular hollow sections in bending. Journal of Materials Processing Technology. 2001(113): 609-704.
[70] Paulsen, F., Welo, T. Cross-sectional deformations of rectangular hollow sections in bending: PartⅡ-analytical models. International Journal of Mechanical Science. 2001(43): 131-152.
[71]吉田正敏,藤原昭文.アルミ中空矩形断面形材の曲げ加工におけるしわ,ひずみ量予测.塑性と加工. 1997, 38(440): 803-808.
[72]吉田正敏,藤原昭文.アルミニウム中空矩形断面形材の曲げ加工におけるしわ发生限界曲げ半径の予测.塑性と加工. 2000(41): 74-78.
[73] Endow, J., Murofa, T.圆管横截面在均匀弯曲时的变扁.世界塑性加工最新技术译文集[C].中国机械工程学会、中国金属学会轧钢学会译.机械工程出版社. 1987: 461-465.
[74] Marcal, P.V., King, I.D. Elastic-plastic Analysis of Two-dimensional Stress System by the F inite Element Method. Int. J. Mech. Sci. 1967(9):143-155.
[75] Yamada, Y., Yoshimura, N., Sakurai, T. Plastic Stress-strain Matrix and its Application for the Solutions of Elastic-plastic Problems by the Finite Element Method. Int. J. Mech. Sci. 1967(10): 343-354.
[76] Trana, K. Finite element simulation of the tube hydroforming process-bending, performing and hydroforming. Journal of Materials Processing Technology. 2002(127): 401-408.
[77]胡福泰.异型管材与型材无模弯曲工艺理论与实验研究[博士学位论文].东北重型机械学院. 1995
[78] Yang, J.B., Jeon, B.H., Oh, S.I. The tube bending Technology of a Hydroforming Process for An Automotive Part. J. of Mats. Proc. Tech. 2001(111): 175-181.
[79] Han, L.H., He, S.Y., Wang, Y.P., etc. Limit Moment of Local Wall Thinning in Pipe UnderBending. Int. J. of Press. Vess. Piping. 1999: 539-542.
[80] ASM Metals Handbook. Forming and Forging. Vol. 14. Materials Park, Ohio: ASM International. 2000.
[81]张君.加热弯管工艺计算机数值模拟[硕士学位论文].西北工业大学. 2001.
[82] ASM Metals Handbook. Forming of Copper and Copper Alloys. Vol. 14. Materials Park, Ohio: ASM International. 1993.
[83] Luo, A.A., Sachdev, A.K. Development of a moderate temperature bending process for magnesium alloy extrusions. Materials Science Forum. 2005(488-489): 477-482.
[84] Luo, A.A., Sachdev, A.K. Bending and Hydroforming of Aluminum and Magnesium. Alloy Tubes for Automotive Applications. Proceedings of the 3rd North American, Hydroforming Conference. Novi. MI. 2005(26-28): 1-13.
[85] Luo, A.A., Sachdev, A.K. Bendability and Microstructure of Magnesium Alloy Tubes at Room and Elevated Temperatures. Magnesium Technology 2005. TMS, Warrendale, PA. 2005: 145-148.
[86] Takahashi, H., Oishi, Y., Wakamatsu, K., etc. Tensile Properties and Bending Formability of Drawn Magnesium Alloy Pipes. Materials Science Forum. 2003(419-422): 345.
[1] ASM Specialty Handbook. Magnesium and Magnesium alloys. Materials Park, Ohio: ASM International. 2000.
[2]王迎新. Mg-Al合金晶粒细化、热变形行为及加工工艺的研究[博士论文].上海:上海交通大学. 2006.
[3]刘满平. Mg-Al-Ca合金微观组织、力学性能和蠕变变形行为[博士论文].上海:上海交通大学. 2004.
[4]周海涛. Mg-6Al-1Zn合金高温塑性变形行为及管材热挤压研究[博士论文].上海:上海交通大学. 2004.
[5]中国标准出版社第二编辑室编.金属力学性能及工艺性能试验方法.北京:中国标准出版社. 2001.
[6]吴文云,张平,姚寿山,等.全自动数控液压热弯机.外观设计专利,专利号ZL 2007 3 0086596.2.
[7]吴文云,张平,姚寿山,等.用于热弯的数控弯管机模具.实用新型专利.专利号ZL 2007 2 0198534.5.
[8]艾治勇.弯管的弯曲成形分析及其力学特性研究[硕士论文].上海:上海交通大学. 2005.
[9]电子背散射分析方法通则,GB/T19501-2004.
[10]陈勇军.往复挤压镁合金的组织结构与力学性能研究[博士论文].上海:上海交通大学,2007
[11] Mishra, R.K., Gupta, A.K., Rao, P.R., etc. Influence of cerium on the texture and ductility of magnesium extrusions. Scr. Mater. 2008(59): 562-565.
[1] Wang, Y., Jin, L., Zeng, X. Microstructure and Bendability of AM60 and AZ61 Magnesium Alloy Tubes. Magnesium Technology. 2008: 165-170.
[2]余永宁.金属学原理.北京:冶金工业出版社. 2000.
[3]陈振华.变形镁合金.北京:化学工业出版社. 2005.
[4] Chandrasekaran, M., Ming, Y., John, S. Effect of materials and temperature on the forward extrusion of magnesium alloys. Materials Science and Engineering A. 2004(381): 308-319.
[5]王迎新. Mg-Al合金晶粒细化、热变形行为及加工工艺的研究[博士论文].上海:上海交通大学. 2006.
[6] Watanabe, H., Tsutsui, H., Mukai, T. Grain size control of commercial wrought Mg-Al-Zn alloys utilizing dynamic recrystallization. Mater Trans JIM. 2001, 42 (7): 1200-1205.
[7] Humpreys, F.J., Hatherly, M. Recrystallization and Related Annealing Phinomena. Printed and bound in Great Britain by Galliard (printers) Ltd. 1995: 363.
[8] Jin, L., Lin, D.L., Mao, D.L., etc. Materials Science and Engineering A. 2006(423): 247-252.
[9] Reed-Hill, R.E., Robertson, W.D. Aditional modes of deformation twinning in magnesium. Acta Metall. 1957(5): 717-727.
[10] Jiang, L., Jonas, J.J., Mishra, R.K., etc. Twinning and texture development in two Mg alloys subjected to loading along three different strain paths. Acta materialia. 2007, 55(11): 3899-3910.
[11] Barnett, M.R. A rationale for the strong dependence of mechanical twinning on grain size. Scripta Materialia. 2008(59): 696-698.
[12] Chino, Y., Kimura, K., Hakamada, M., etc. Mechanical anisotropy due to twinning in an extruded AZ31 Mg alloy. Meterials Sci. Eng. A. 2008(485): 311-317.
[13] Bohlen, J., Chmelík, F., Kaiser, F. Kovo. Mater. 2002(40): 290-297.
[14] Roberts, C.S. Magnesium and Its alloys. John Wiley & Sons, Inc. New York. 1960.
[15]艾治勇.弯管的弯曲成形分析及其力学特性研究[硕士论文].上海:上海交通大学. 2005.
[16]杨觉先.金属塑性变形物理基础.北京:冶金工业出版社. 1988.
[17]陈振华,夏伟军,严红革,等.镁合金材料的塑性变形理论及其技术.化工进展. 2004,23(2): 127-131.
[18] Ion, S.E., Homphreys, F.J., Whice, S.H. Dynamic recrystallization and the development of microstructure during the high temperature deformation of magnesium. Acta Mater. 1982(30): 1909-1919.
[19] Couret, A., Caillard, D. An in-situ study of prismatic glide in magnesium- I. The rate controlling mechanism. Acta Metallurgica Materialia. 1985, 33(8): 1447-1454.
[20] Watanabe, H., Tsutsui, H., Mukai, T. Grain size control of commercial wrought Mg-Al-Zn alloys utilizing dynamic recrystallization. Mater Trans JIM. 2001, 42 (7): 1200-1205.
[21] Klimanek, P., Potzsch, A. Microstructure evolution under compressive plastic deformation of magnesium at different temperatures and strain rates. Meterials Sci. Eng. A. 2002(324): 145-150.
[22] Yoo, M.H., Lee, J.K. Deformation twinning in h.c.p. metals and alloys. Philosophical Magazine A. 1991(63): 987-1000.
[23] Goo, E., Kee, T.P. Application of the von Mises criterion to deformation twinning. Scipta Materialia. 1989(23): 1053-1056.
[24] Asm International. Magnesium And Magnesium Alloy. OH, Metal Park. 1999, 1.
[1]余琨,黎文献,王日初.镁合金塑性变形机制.中国有色金属学报. 2005,15(7): 1081-1086.
[2] Li, H., Yang, H. Trans. Nonferrous Met. Soc. China. 2006(16): 613-623.
[3] Tang, N.C. Plastic-deformation analysis in tube bending, Pressure vessels and piping. 2000(77): 751-759.
[4] Wu, W.Y., Zhang, P., Zeng, X.Q., etc. Bendability of the wrought magnesium alloy AM30 tubes using a rotary draw bender. Mater. Sci. Eng. A. 2008(486): 596-601.
[5] Galiyev, A., Kaibyshev, R., GTottstein, G. Correlation of plastic deformation and dynamic recrystallization in magnesium alloy ZK60. Acta Materialia. 2001(49): 1199-1207.
[6] Mori, S., Manabe, K.-I. Nishimura, H., etc. Experimental analysis of the flattening of the cross-section, the springback and the bending moment of clad tubes in uniform bending. Journal of Materials Processing Technology. 1997(66): 270-276.
[7] Bai, Y., Ragnar, T., Moan, I.T. Tube collapse under combined external pressure, tension andbending. Marine Structure. 1997(10): 389-410.
[8] Al-Qureshi, H.A. Elastic-plastic analysis of tube bending. Machine tools & manufacture. 1999(39): 87-104.
[9]艾治勇.弯管的弯曲成形分析及其力学特性研究[硕士论文].上海:上海交通大学. 2005.
[10] Zhan, M., Yang, H., Huang, L., etc. Spirngback analysis of numerical control bending of thin-walled tube using numerical-analytic method. Journal of Materials Processing Technology. 2006(177): 197-201.
[11] Al-Qureshi, H.A., Russo, A. Spring-back and residual stresses in bending of thin-walled aluminum tubes. Materials & Design. 2002(23): 217-222.
[12]胡忠,夏福清.中频感应局部加热弯管的回弹理论分析和试验研究.固体力学学报. 1998, 19(4): 329-335.
[13] Wang, J.T., Yin, D.L., Liu, J.Q., etc. Effect of grain size on mechanical property of Mg-3Al-1Zn alloy. Scripta Mater. 2008(59): 63-66.
[14] Watanabe, H., Tsutsui, H., Mukai, T. Grain size control of commercial wrought Mg-Al-Zn alloys utilizing dynamic recrystallization. Mater Trans JIM. 2001, 42 (7): 1200-1205.
[1] Gao, L., Strano, M. FEM analysis of tube pre-bending and hydroforming. Journal of Materials Processing Technology. 2004(151): 294-297.
[2] Trana, K. Finite element simulation of the tube hydroforming process-bending, performing and hydroforming. Journal of Materials Processing Technology. 2002(127): 401-408.
[3]张华.管材弯曲成形过程数值模拟的研究[博士学位论文].重庆:重庆大学. 1999.
[4] Lang, L., Yuan, S., Wang, X., etc. A study on numerical simulation of hydroforming of aluminum alloy tube. Journal of Materials Processing Technology. 2004(146): 377-388.
[5] MARC Reference manual. Volume A. 2005.
[6] Asm International. Magnesium and Magnesium Alloy. OH, Metal Park. 1999, 1.
[7]刘鸿文,材料力学(第四版).高等教育出版社.北京: 2005.
[8]陈火红. MSC.Marc / Mentat 2003基础与应用实例.北京:科学出版社. 2004.
[9] Yang, J-B., Jeon, B-H., Oh, S.-I. The tube bending technology of a hydroforming process for an automotive part. Journal of Materials Processing Technology. 2001(111): 175-181.
[10] Li, H., Yang, H., Zhan, M., etc. The interactive effects of wrinkling and other defects in thin-walled tube NC bending process. Journal of Materials Processing Technology. 2007(187-188): 502-507.
[11] Al-Qureshi, H.A., Russo, A. Spring-back and residual stresses in bending of thin-walled aluminum tubes. Materials and Design. 2002(23): 217-222.
[12] Trana, K. Finite element simulation of the tube hydroforming process-bending, performing and hydroforming. Journal of Materials Processing Technology. 2002(127): 401-408.
[13] Yang, H., Lin, Y. Wrinkling analysis for forming limit of tube bending processes. Journal of Materials Processing Technology. 2004(152): 363-369.
[14] Bai, Y., Ragnar, T., Moan, I.T. Tube collapse under combined external pressure, tension and bending. Marine Structure. 1997(10): 389-410.
[15] Mori, S., Manabe, K.-I., Nishimura, H. Experimental analysis of the flattening of the cross section, the springback and the bending moment of clad tubes in uniform bending. Journal of Materials Processing Technology. 1997(66): 270-276.
[1] Yoo, M.H. Slip, twinning, and fracture in hexagonal close-packed metals. Metallurgical Transactions A. 1981(12): 409-418.
[2] Wang, Y.N., Huang, J.C. Texture analysis in hexagonal materials. Materials Chemistry and Physics. 2003(81): 11-26.
[3] Jin, L., Wu, W.Y., Mishra, R.K., etc. Deformation Mechanisms in AZ31 Magnesium Alloy Tube Bending. Magnesium Technology (TMS). 2009: 429-434.
[4] Takuda, H., Fujimoto, H., Hatta, N. Modelling on flow stress of Mg-Al-Zn alloys at elevated temperatures. Journal of Materials Processing Technology. 1998(80-81): 513-516.
[5] Christian, J.W., Mahajan, S. Deformation twinning. Progress in Materials Science. 1995(39): 1-15.
[6] Buchanan, E.R., Reed-Hill, R.E. Stress-strain behavior of magnesium single crystals deformed by rotational slip. Transactions of the Metallurgical Society of AIME. 1969, 245(9): 1929-1935.
[7] Koike, J., Kobayashi, T., Mukai, T., etc. The activity of non-basal slip system and dynamic recovery at room temperature in fine-grained AZ31B magnesium alloys. Acta Materialia. 2003(51): 2055-2065.
[8] Reed-Hill, R.E., Robertson, W.D. Aditional modes of deformation twinning in magnesium. Acta Metall. 1957(5): 717-727.
[9] Couret, A., Caillard, D. Prismatic slip in beryllium I. The controlling mechanism at the peak temperature. Philosophical Magazine A. 1989(59): 783-800.
[10] Flynn, P.W., Mote, J., Dorn, J.E. On the thermally activated mechanism of prismatic slip in magnesium single crystals. Trans. TMS-AIME. 1961(221): 1148-1154.