一种新型近β型Ti-5.5Mo-6V-7Cr-4Al-2Sn-1Fe合金热变形行为
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摘要
采用Gleeble-3800型热模拟试验机对一种新型近β型Ti-5.5Mo-6V-7Cr-4Al-2Sn-1Fe(质量分数/%)钛合金进行等温恒应变速率压缩实验。变形温度范围为:655～855℃,应变速率范围为:0.001～10s~(-1),最大真应变为0.8。根据实验数据,建立了该合金的高温流变应力模型,计算出热变形激活能约为255kJ/mol,并绘制出热加工图。结合热加工图与材料的显微组织分析可知,在高应变速率(1～10s~(-1))条件下变形时,在热加工图上表现为材料的功率耗散值(η)低,为失稳区域,易产生绝热剪切带与局部塑性流动、开裂等现象。在应变速率小于0.01s~(-1)和相变点(T_β)温度以下(655～755℃)进行热变形时,组织变化主要以动态回复为主;在应变速率小于0.01s~(-1)和T_β以上(755～855℃)进行热变形时,组织发生动态再结晶,且随着温度的升高,新产生的再结晶晶粒逐渐长大。在相变点附近(755～770℃),变形速率为0.001～0.003s~(-1)区域内变形时,功率耗散值达到最大值,组织发生动态再结晶,该区域为合金热变形的"安全区"。
The isothermal constant strain rate compression tests of Ti-5.5 Mo-6 V-7 Cr-4 Al-2 Sn-1 Fe alloy were conducted by Gleeble-3800 simulator. The hot deformation temperature range is from 655℃ to 855℃ and the strain rate range is from 0.001 s~(-1) to 10 s~(-1) and the maximum true strain is 0.8. A high temperature flow stress model was built with activation energy of 255 kJ/mol according to the experimental results for the alloy and the processing map of alloy was constructed according to DMM model. The metallographic analysis of alloy shows that the alloy exhibits domain of flow localization and adiabatic shear bands and low power dissipation efficiency in the high strain rate(1-10 s~(-1)). The alloy undergoes dynamic recovery in the temperature region of 655-755℃ and the strain rate below 0.01 s~(-1). The dynamic recrystallization takes place at the strain rate below 0.01 s~(-1) and in the temperature region of 755-855℃, the original deformed grains and recrystallized grains gradually grow with the increase of temperature. When the temperature is 755-770℃ and the strain rate is 0.001-0.003 s~(-1), the alloy's power dissipation efficiency reaches the maximum and the recrystallized grain is uniform and fine. These regions can be considered as the optimal parameter range of isothermal compression for the alloy.
The isothermal constant strain rate compression tests of Ti-5.5 Mo-6 V-7 Cr-4 Al-2 Sn-1 Fe alloy were conducted by Gleeble-3800 simulator. The hot deformation temperature range is from 655℃ to 855℃ and the strain rate range is from 0.001 s~(-1) to 10 s~(-1) and the maximum true strain is 0.8. A high temperature flow stress model was built with activation energy of 255 kJ/mol according to the experimental results for the alloy and the processing map of alloy was constructed according to DMM model. The metallographic analysis of alloy shows that the alloy exhibits domain of flow localization and adiabatic shear bands and low power dissipation efficiency in the high strain rate(1-10 s~(-1)). The alloy undergoes dynamic recovery in the temperature region of 655-755℃ and the strain rate below 0.01 s~(-1). The dynamic recrystallization takes place at the strain rate below 0.01 s~(-1) and in the temperature region of 755-855℃, the original deformed grains and recrystallized grains gradually grow with the increase of temperature. When the temperature is 755-770℃ and the strain rate is 0.001-0.003 s~(-1), the alloy's power dissipation efficiency reaches the maximum and the recrystallized grain is uniform and fine. These regions can be considered as the optimal parameter range of isothermal compression for the alloy.
引文
[1] 李青云.稀有金属材料加工手册[M].北京:冶金工业出版社,1984:3-4.LI Q Y.Rare metal processing manual[M].Beijing:Metallurgical Industry Press,1984:3-4.
[2] FAN J K,KOU H C,LAI M J,et al.Characterization of hot deformation behavior of a new near beta titanium alloy:Ti-7333[J].Materials & Design,2013,49:945-952.
[3] 王哲,王新南,商国强,等.新型超高强韧钛合金热变形行为研究[J].稀有金属材料与工程,2018,47(3):810-815.WANG Z,WANG X N,SHANG G Q,et al.Study on hot deformation behavior of new high strength and toughness titanium alloy[J].Rare Metal Materials and Engineering,2018,47(3):810-815.
[4] BOBBILI R,RAMUDU B V,MADHU V.A physically-based constitutive model for hot deformation of Ti-10-2-3 alloy[J].Journal of Alloys & Compounds,2016,696:295-303.
[5] WANG R,XI Z,ZHAO Y,et al.Hot Deformation microstructure and mechanism of Ti53311S titanium alloy[J].Rare Metal Materials & Engineering,2008,37(8):1356-1359.
[6] PRASAD Y V R K,SESHACHARYULU T.Processing maps for hot working of titanium alloys[J].Materials Science & Engineering:A,1998,243(1/2):82-88.
[7] TAMIRISAKANDALA S,BHAT R B,VEDAM B V.Recent advances in the deformation processing of titanium alloys[J].Journal of Materials Engineering & Performance,2003,12(6):661-673.
[8] SELLARS C M,TEGART W J.On the mechanism of hot deformation[J].Acta Metallurgica,1966,14(9):1136-1138.
[9] JONAS J J,SOMANI M C,TEGART W J.Strength and structure under hot-working conditions[J].Metallurgica Reviews,1969,14(1):1-24.
[10] PRASAD Y V R K,GEGEL H L,DORAIVELU S M,et al.Modeling of dynamic material behavior in hot deformation:forging of Ti-6242[J].Metallurgical and Materials Transactions A,1984,15(10):1883-1892.
[11] PRASAD Y V R K.Processing maps:a status report[J].Journal of Materials Engineering & Performance,2003,12(6):638-645.
[12] ZIEGLER H.Progress in solid mechanics[M].New York:Wiley Press,1963.
[13] BHAT B V R,MAHAJAN Y R,ROSHAN H M,PRASAD Y.Processing map for hot working of powder[J].Metallurgical Transactions A,1992,23 (8):2223-2230.
[14] 刘延辉,姚泽坤,宁永权,等.生物医用TC20钛合金高温变形行为及其本构关系[J].材料工程,2014(7):16-21.LIU Y H,YAO Z K,NING Y Q,et al.Hot deformation behavior and constitutive relationship of biomedical TC20 alloy[J].Journal of Materials Engineering,2014(7):16-21.
[15] SESHACHARYULU T,MEDEIROS S C,MORGAN J T,et al.Hot deformation mechanisms in ELI Grade Ti-6Al-4V[J].Scripta Materialia,1999,41(3):283-288.
[16] ZHU Y,ZENG W,FENG F,et al.Characterization of hot deformation behavior of as-cast TC21 titanium alloy using processing map[J].Materials Science and Engineering:A,2011,528(3):1757-1763.
[17] 黄烁,王磊,张北江,等.GH4706合金的热变形行为与显微组织演化[J].材料工程,2015,43(2):41-46.HUANG S,WANG L,ZHANG B J,et al.Hot deformation behavior and microstructure evolution of GH4706 alloy[J].Journal of Materials Engineering,2015,43(2):41-46.
[18] 赵映辉,葛鹏,赵永庆,等.Ti-1300合金的热变形行为研究[J].稀有金属材料与程,2009,38(1):46-49.ZHAO Y H,GE P,ZHAO Y Q,et al.Hot deformation behavior of Ti-1300 alloy[J].Rare Metal Materials and Engineering,2009,38(1):46-49.
[2] FAN J K,KOU H C,LAI M J,et al.Characterization of hot deformation behavior of a new near beta titanium alloy:Ti-7333[J].Materials & Design,2013,49:945-952.
[3] 王哲,王新南,商国强,等.新型超高强韧钛合金热变形行为研究[J].稀有金属材料与工程,2018,47(3):810-815.WANG Z,WANG X N,SHANG G Q,et al.Study on hot deformation behavior of new high strength and toughness titanium alloy[J].Rare Metal Materials and Engineering,2018,47(3):810-815.
[4] BOBBILI R,RAMUDU B V,MADHU V.A physically-based constitutive model for hot deformation of Ti-10-2-3 alloy[J].Journal of Alloys & Compounds,2016,696:295-303.
[5] WANG R,XI Z,ZHAO Y,et al.Hot Deformation microstructure and mechanism of Ti53311S titanium alloy[J].Rare Metal Materials & Engineering,2008,37(8):1356-1359.
[6] PRASAD Y V R K,SESHACHARYULU T.Processing maps for hot working of titanium alloys[J].Materials Science & Engineering:A,1998,243(1/2):82-88.
[7] TAMIRISAKANDALA S,BHAT R B,VEDAM B V.Recent advances in the deformation processing of titanium alloys[J].Journal of Materials Engineering & Performance,2003,12(6):661-673.
[8] SELLARS C M,TEGART W J.On the mechanism of hot deformation[J].Acta Metallurgica,1966,14(9):1136-1138.
[9] JONAS J J,SOMANI M C,TEGART W J.Strength and structure under hot-working conditions[J].Metallurgica Reviews,1969,14(1):1-24.
[10] PRASAD Y V R K,GEGEL H L,DORAIVELU S M,et al.Modeling of dynamic material behavior in hot deformation:forging of Ti-6242[J].Metallurgical and Materials Transactions A,1984,15(10):1883-1892.
[11] PRASAD Y V R K.Processing maps:a status report[J].Journal of Materials Engineering & Performance,2003,12(6):638-645.
[12] ZIEGLER H.Progress in solid mechanics[M].New York:Wiley Press,1963.
[13] BHAT B V R,MAHAJAN Y R,ROSHAN H M,PRASAD Y.Processing map for hot working of powder[J].Metallurgical Transactions A,1992,23 (8):2223-2230.
[14] 刘延辉,姚泽坤,宁永权,等.生物医用TC20钛合金高温变形行为及其本构关系[J].材料工程,2014(7):16-21.LIU Y H,YAO Z K,NING Y Q,et al.Hot deformation behavior and constitutive relationship of biomedical TC20 alloy[J].Journal of Materials Engineering,2014(7):16-21.
[15] SESHACHARYULU T,MEDEIROS S C,MORGAN J T,et al.Hot deformation mechanisms in ELI Grade Ti-6Al-4V[J].Scripta Materialia,1999,41(3):283-288.
[16] ZHU Y,ZENG W,FENG F,et al.Characterization of hot deformation behavior of as-cast TC21 titanium alloy using processing map[J].Materials Science and Engineering:A,2011,528(3):1757-1763.
[17] 黄烁,王磊,张北江,等.GH4706合金的热变形行为与显微组织演化[J].材料工程,2015,43(2):41-46.HUANG S,WANG L,ZHANG B J,et al.Hot deformation behavior and microstructure evolution of GH4706 alloy[J].Journal of Materials Engineering,2015,43(2):41-46.
[18] 赵映辉,葛鹏,赵永庆,等.Ti-1300合金的热变形行为研究[J].稀有金属材料与程,2009,38(1):46-49.ZHAO Y H,GE P,ZHAO Y Q,et al.Hot deformation behavior of Ti-1300 alloy[J].Rare Metal Materials and Engineering,2009,38(1):46-49.