采用热轧制备晶粒尺寸为0.1~0.5μm的超细晶Ti-55511近β钛合金，利用SEM和TEM等研究热处理工艺对超细晶合金显微组织和力学性能的影响。结果表明，在350~650℃的温度条件下，合金强度和硬度随温度的升高呈现先增高后降低的趋势，在450℃时达到峰值强度1486.09 MPa；在450℃退火时，随着退火时间的延长，合金强度首先急剧上升至1536 MPa后趋于稳定，伸长率呈现先增加后下降的趋势；合金在退火过程中主要经历动态回复过程，未发生明显的粗化长大现象，晶粒尺寸均小于1μm。动态回复过程在消除加工硬化的同时促进了晶界/相界的稳定化，增强细晶强化作用；退火过程中发生α→α2和β→ω→α相变过程，第二相粒子弥散强化效应增强。但是当第二相粒子尺寸增大至一定程度时，会显著降低合金的塑性。退火过程中合金力学性能的变化与强化机制的作用有关。
The ultra-fine grained (UFG) Ti-55511 nearβtitanium alloy with grain size of 0.1-0.5μm was prepared by hot rolling. The effects of heat treatment on the microstructure and mechanical properties were investigated by SEM and TEM. The results indicate that both the strength and hardness of the alloy increase firstly and then reduce with increasing the heat treatment temperature from 350℃to 650℃. The peak strength of 1486.09 MPa appears at 450℃. The strength dramatically reaches 1536 MPa and then becomes stable with prolonging the holding time when heat-treated at 450℃. While the maximum elongation increases firstly and then decreases. During the annealing process the dynamic recovery occurs in the alloy and the grain size remains smaller than 1μm. The dynamic recovery stimulates the grain refinement effect by eliminating the hardening process and improves the stability of the grain boundary/phase boundary. The phase transitions of α→α2 and β→ω→α enhance the second phase particle dispersion effect during the annealing process. However, the ductility of alloy significantly decreases when the second phase particles grow up to a certain size. The mechanical property evolution during annealing process is mainly related to the effect of strengthening mechanisms.
参考文献
| [1] | 韩栋,张鹏省,毛小南,卢亚锋,奚正平,杨建朝.BT22钛合金及其大型锻件的研究进展[J].材料导报,2010(03):46-50. |
| [2] | 沙爱学,王庆如,李兴无.航空用高强度结构钛合金的研究及应用[J].稀有金属,2004(01):239-242. |
| [3] | BOYER R.R .An overview on the use of titanium in the aerospace industry[J].Materials Science and Engineering A,1996,213(1/2):103-114. |
| [4] | Dehghan-Manshadi, A.;Dippenaar, R.J. .Development of α-phase morphologies during low temperature isothermal heat treatment of a Ti-5Al-5Mo-5V-3Cr alloy[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2011(3):1833-1839. |
| [5] | 王清瑞;沙爱学;黄旭;刘宇 .热处理制度对TC18A 钛合金丝材组织和性能的影响[J].中国有色金属学报,2010,20(专辑1):s634-s637. |
| [6] | Jackson, M;Jones, NG;Dye, D;Dashwood, RJ .Effect of initial microstructure on plastic flow behaviour during isothermal forging of Ti-10V-2Fe-3Al[J].Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing,2009(1/2):248-254. |
| [7] | Li, C.;Zhang, X.-Y.;Zhou, K.-C.;Peng, C.-Q..Relationship between lamellar α evolution and flow behavior during isothermal deformation of Ti-5Al-5Mo-5V-1Cr-1Fe near Β titanium alloy[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2012:668-674. |
| [8] | A.V. Sergueeva;V.V. Stolyarov;R.Z. Valiev .Advanced mechanical properties of pure titanium with ultrafine grained structure[J].Scripta materialia,2001(7):747-752. |
| [9] | Zherebtsov, S.;Kudryavtsev, E.;Kostjuchenko, S.;Malysheva, S.;Salishchev, G..Strength and ductility-related properties of ultrafine grained two-phase titanium alloy produced by warm multiaxial forging[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2012:190-196. |
| [10] | XU W;WU X;CALIN M;STOICA M ECKERT J XIA K .Formation of an ultrafine-grained structure during equal-channel angular pressing of aβ-titanium alloy with low phase stability[J].Scripta Materialia,2009,60(11):1012-1015. |
| [11] | Yuri Estrin;Alexei Vinogradov .Fatigue behaviour of light alloys with ultrafine grain structure produced by severe plastic deformation: An overview[J].International Journal of Fatigue,2010(6):898-907. |
| [12] | Qiang, G.;Qing, W.;Dong-Li, S.;Xiu-Li, H.;Gao-Hui, W. .Formation of nanostructure and mechanical properties of cold-rolled Ti-15V-3Sn-3Al-3Cr alloy[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2010(16/17):4229-4232. |
| [13] | S. Zherebtsov;M. Murzinova;G. Salishchev .Spheroidization of the lamellar microstructure in Ti-6Al-4V alloy during warm deformation and annealing[J].Acta materialia,2011(10):4138-4150. |
| [14] | PeiQing La;JiQiang Ma;Yuntian T. Zhu .Dry-sliding tribological properties of ultrafine-grained Ti prepared by severe plastic deformation[J].Acta materialia,2005(19):5167-5173. |
| [15] | Weiss I.;Semiatin SL. .Thermomechanical processing of beta titanium alloys - an overview[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,1998(1/2):46-65. |
| [16] | JONES N G;DASHWOOD R J;JACKSON M;DYE D .βphase decomposition in Ti-5Al-5Mo-5V-3Cr[J].Acta Materialia,2009,57(13):3830-3839. |
| [17] | Li, C.;Zhang, X.-Y.;Li, Z.-Y.;Zhou, K.-C..Hot Deformation of Ti-5Al-5Mo-5V-1Cr-1Fe Near Β Titanium Alloys Containing Thin and Thick Lamellar α Phase[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2013:75-83. |
| [18] | 官杰,刘建荣,雷家峰,刘羽寅.TC18钛合金的组织和性能与热处理制度的关系[J].材料研究学报,2009(01):77-82. |
| [19] | 沙爱学,李兴无,王庆如,鲍如强.热变形温度对TC18钛合金显微组织和力学性能的影响[J].中国有色金属学报,2005(08):1167-1172. |
| [20] | Shankar Azad;R.K. Mandal;A.K. Singh .Effect of Mo addition on transformation behavior of (α_2 + γ) based Ti-Al alloys[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2006(1/2):219-224. |
| [21] | HUANG A J;LI G P;HAO Y L;YANG R .Acicular α2 precipitation induced by capillarity at α/β phase boundaries in Ti-14Al-2Zr-3Sn-3Mo-0.5Si titanium alloy[J].Acta Materialia,2003,51(16):4939-4952. |
| [22] | JONES N G;DASHWOOD R J;JACKSON M;DYE D .Development of chevron-shaped a precipitates in Ti-5Al-5Mo-5V-3Cr[J].Scripta Materialia,2009,60(07):571-583. |
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