Aging Effect on Microstructure of Cold Groove-Rolled α′-Type Ti–12 mass%V–2 mass%Al Alloys Studied by Transmission Electron Microscopy
Aging Effect on Microstructure of Cold Groove-Rolled α′-Type Ti–12 mass%V–2 mass%Al Alloys Studied by Transmission Electron Microscopy
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透射电镜研究时效对冷坡口轧制α′型Ti-12mass%V-2mass%Al合金显微组织的影响
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
T. Konno
中科院分区：
文献类型：
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作者：
Kazuhisa Sato;H. Matsumoto;A. Chiba;T. Konno
用透射电镜和电子衍射研究了冷槽轧制（CGR）Ti-12mass%V-2mass%Al合金中六方A型马氏体的显微组织和相分解。冷轧变形量为75%时，由针状马氏体转变为等轴状马氏体。在573 K时效500 h后，由于回复效应，局部莫尔条纹消失，衍射环变得尖锐。然而，尽管恢复，维氏硬度也增加。溶质原子的分配和/或细沉淀物的形成可能是观察到的时效硬化的原因。虽然CGR合金具有多晶等轴晶组织的特征，但在673 K时效后，局部观察到以下取向关系：（101）、/01111、[010]、/21011。电子层析成像显示，在变形后的A基体中，析出相的形核和生长是不均匀的。[doi：10.2320/matertrans.M2013463]
Microstructure and phase decomposition of hexagonal ¡A martensite in cold groove rolled (CGR) Ti12mass%V2mass%Al alloys have been studied by transmission electron microscopy and electron diffraction. Acicular structure of the ¡A martensite changes into equiaxed ¡A grains by CGR with a cold reduction of 75%. After aging at 573K for 500 h, local Moiré fringes disappear and diffraction rings become sharp due to recovery. However, Vickers hardness also increased in spite of the recovery. Partitioning of solute atoms and/or formation of fine precipitates can be possible cause for the observed age-hardening. Although a CGR alloy is characterized by a microstructure with polycrystalline equiaxed grains, following orientation relationship is locally observed between ¢ precipitates and ¡ grains after aging at 673K: (101)¢ // ð01 1 1Þ¡, [010]¢ // 1⁄210 11 ¡. Electron tomography revealed a heterogeneous nucleation and growth of ¢ precipitates in the deformed ¡A matrix. [doi:10.2320/matertrans.M2013463]