锻压技术

高速冲击载荷下Ti6242钛合金的绝热剪切行为及裂纹扩展机理

英文标题：Adiabatic shear behavior and crack propagation mechanism on Ti6242 titanium alloy under high-speed impact loading

作者：彭德平刘筱贺丹丹万步炎陈阳刘文辉

单位：1.湖南科技大学机电工程学院 2.湘潭华进重装有限公司 3.湖南胜利湘钢钢管有限公司

分类号：TG389

出版年,卷(期):页码：2022,47(9):224-229

摘要：

为了研究Ti6242钛合金在不同冲击载荷下的绝热剪切行为和裂纹扩展机理，采用分离式Hopkinson Bar技术，在室温下对其进行冲击平均应变速率为3069~11337 s-1的冲击试验，使用光学显微镜对其微观组织中的绝热剪切行为进行分析，并建立了裂纹形核及扩展模型。结果表明：Ti6242钛合金的抗冲击强度对冲击平均应变速率不敏感，塑性随着冲击平均应变速率的增加呈现增加趋势；绝热剪切带的数量随着冲击平均应变速率的增加而增加，片层状分布的α/β相会阻碍绝热剪切带的扩展，导致绝热剪切带出现分叉现象；高速冲击载荷下，孔洞在绝热剪切带内形核、长大、合并，最终形成微裂纹，微裂纹通过与前端孔洞合并继续扩展而形成宏观裂纹，导致材料断裂失效。

In order to study the adiabatic shear behavior and crack propagation mechanism of Ti6242 titanium alloy under different impact loading, the impact test with average impact strain rate of 3069-11337 s-1 at room temperature was carried out by split Hopkinson Bar technique. Then, the adiabatic shear behavior in microstructure was analyzed by optical microscope, and the crack nucleation and propagation model was established. The results show that the impact strength of Ti6242 titanium alloy is not sensitive to average impact strain rate, and the plasticity displays an increasing trend with the increasing of the average impact strain rate. The number of adiabatic shear bands increases with the increasing of the average impact strain rate, and α/β phase in lamellar distribution hinders the propagation of adiabatic shear band, resulting in the bifurcation phenomenon of adiabatic shear bands. Under the high-speed impact loading, the pores nucleate, grow and merge in the adiabatic shear band, and finally form micro-cracks, which continue to expand by merging with the front-end holes to form macro-cracks, resulting in fracture failure of material.

基金项目：

国家自然科学基金资助项目(51905166，52071139)；湖南省教育厅优秀青年基金项目（21B0471）

彭德平（1987-），男，博士研究生 E-mail：eden7321@163.com 通信作者：刘筱（1988-），女，博士，副教授，博士生导师 E-mail：liuxiao0105@163.com

参考文献：

[1]Rezaee M, Zarei-Hanzaki A, Mohamadizadeh A, et al. High-temperature flow characterization and microstructural evolution of Ti6242 alloy: Yield drop phenomenon[J]. Materials Science and Engineering: A,2016,673:346-354.

[2]Echlin M, Stinville J C, Miller V M, et al. Incipient slip and long range plastic strain localization in microtextured Ti-6Al-4V titanium[J]. Acta Materialia,2016,114:164-175.

[3]Xavier Boyat,Dorick Ballat-Durand,Julie Marteau,et al. Interfacial characteristics and cohesion mechanisms of linear friction welded dissimilar titanium alloys: Ti-5Al-2Sn-2Zr-4Mo-4Cr (Ti17) and Ti-6Al-2Sn-4Zr-2Mo(Ti6242)[J]. Materials Characterization,2019,158:109942.

[4]Xi G Q, Lei J F, Q J K, et al. A semi-quantitative explanation of the cold dwell effect in titanium alloys[J]. Materials & Design,2020,194:108909.

[5]张磊, 胡时胜, 吴家俊. α-钛合金TA6的动态力学性能和剪切现象分析[J]. 实验力学,2005，20(4):567-572.

Zhang L, Hu S S, Wu J J. Analysis of adiabatic shearing phenomenon and dynamic mechanical performance on TA-6 of α-titanium alloy[J]. Experimental Mechanics,2005,20(4):567-572.

[6]孙坤, 程兴旺, 王富耻, 等. 组织及应变速率对TC6钛合金绝热剪切敏感性的影响[J]. 稀有金属材料与工程,2008,37(10):1856-1860.

Sun K, Cheng X W, Wang F C, et al. Study on sensitivity of adiabatic shear of TC6 alloy under different strain rate and morphology[J]. Rare Metal Materials and Engineering,2008,37(10):1856-1860.

[7]Yang Y, Li X M, Tong X L, et al. Effects of microstructure on the adiabatic shearing behaviors of titanium alloy[J]. Materials Science and Engineering：A, 2011, 528(7-8): 3130-3133.

[8]周琳，刘运玺，陈玮，等. Ti-4Al-5Mo-6Cr-5V-1Nb合金的热变形行为及热加工图[J]. 稀有金属，2022,46(1):27-35.

Zhou L, Lin Y X, Chen W, et al. Thermal deformation behavior and processing map of Ti-4Al-5Mo-6Cr-5V-1Nb alloy[J]. Chinese of Rare Metal,2022,46(1):27-35.

[9]彭美旗, 程兴旺,郑超,等. 次生片层α相宽度对双态组织TC4钛合金动态压缩性能及其绝热剪切敏感性的影响[J]. 稀有金属材料与工程,2017,46(7):1843-1849.

Peng M Q, Cheng X W, Zheng C, et al. Effects of secondary α phase width on dynamic mechanical properties and sensitivity of adiabatic shear banding in bimodal microstructures of TC4 alloy[J]. Rare Metal Materials and Engineering,2017,46(7):1843-1849.

[10]毛萍莉, 刘超, 刘正, 等. AZ31镁合金中绝热剪切带的组织演变规律[J]. 稀有金属材料与工程,2015,44(5):1181-1184.

Mao P L, Liu C, Liu Z，et al. Microstructure evolution of adiabatic shear bands in AZ31 magnesium alloy[J]. Rare Metal Materials and Engineering, 2015,44(5):1181-1184.

[11]Mendoza I, Villalobos D, Alexandrov B T. Crack propagation of Ti alloy via adiabatic shear bands[J]. Materials Science and Engineering: A,2015,645: 306-310.

[12]Liu X, Zhou Y, Zhu X J, et al. The failure mechanism at adiabatic shear bands of titanium alloy: High-precision survey using precession electron diffraction and geometrically necessary dislocation density calculation[J]. Materials Science and Engineering:A,2019,746:322-331.

[13]Zhou S, Deng C, Liu S, et al. Microstructure, texture, and fracture of pure magnesium adiabatic shear band under high strain rate compression[J]. Materials Science and Engineering: A,2021,822:141632.

[14]张明达, 曹京霞, 隋楠, 等. 高载荷作用下Ti6242钛合金低周疲劳和保载疲劳损伤行为分析[J].航空材料学报,2019,39(1):55-61.

Zhang M D, Cao J X, Sui N, et al. Fracture behavior of low cycle fatigue and dwell fatigue of Ti6242 titanium alloy under high load[J]. Aeronautical Materials,2019,39(1):55-61.

[15]张明达,曹京霞,翟战江,等.保载时间和应力比对Ti6242合金应力应变响应影响[J].中国有色金属学报,2022,32(6):1685-1694.

Zhang M D, Cao J X, Zhai Z J, et al. Effects of dwell time and stress ratio on the stress and strain responses of Ti6242 alloy[J]. The Chinese Journal of Nonferrous Metals，2022,32(6):1685-1694.

[16]李宏辉, 王柯, 辛仁龙, 等. 双态组织TA19钛合金高温变形过程中的微观组织演变机制[J]. 材料热处理学报,2020,41(8):27-34.

Li H H, Wang K, Xin R L, et al. Microstructure evolution mechanism of TA19 titanium alloy with bi-modal structure during high temperature deformation[J]. Transactions of Materials and Heat Treatment,2020,41(8):27-34.

[17]梁运兴, 王龙祥, 魏志坚, 等. 热变形对TA19闪光焊接组织均匀化的影响[J]. 稀有金属材料与工程,2020,49(5):1757-1756.

Liang Y X, Wang L X, Wei Z J, et al. Effect of hot deformation on microstructure homogenization of flash welded TA19 alloy[J]. Rare Metal Materials and Engineering,2020, 49 (5):1757-1756.

[18]Furuhara T, Maki T. Variant selection in heterogeneous nucleation on defects in diffusional phase transformation and precipitation[J]. Materials Science and Engineering: A,2001,312(1-2):145-154.

[19]Yang Y, Jiang L H. Effect of heat treatment on adiabatic shear susceptibility in ZK60 magnesium alloy[J]. Materials Science and Engineering: A, 2016, 664:146-154.

[20]Yang Y, Jiang L H, Xu Z, et al. An examination of adiabatic shearing behavior in ZK60 alloy with different states of heat treatment[J].Materials Science and Engineering: A, 2017, 685:57-64.

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