摘要
本文针对Ti_(2)AlNb热轧板热处理后的组织呈现出的反常取向分层状态进行了分析。利用扫描电子显微镜(SEM)和电子背散射衍射(EBSD)对热轧态和热处理态样品的组织进行了表征,发现热轧态样品内低温平衡相的O相比例高于60%,呈现了类似再结晶的近等轴组织,且大部分β相与O相符合{110}_(β)//{001}_(O)、<111>_(β)//<1-10>_(O)的取向关系。而后继续高温热处理,使得O相向高温β相转变,快冷保留了高温β相,β相呈现明显取向分层现象。热处理前后β相的织构类型未发生明显变化,表明高温β相的形成是热轧态样品中的已有β相晶粒在高温下吞噬周围O相晶粒而长大的过程,并因此而导致β相的取向分布状态保留到了相变之后,从而呈现出独特的取向分层状态。热轧板中的等轴组织是由于高温β相相变形成,低温O相的强织构是由高温β相强织构继承而来。本结果为Ti_(2)AlNb热轧组织的理解和组织调控提供了基础。
This paper analyzes the anomalous orientation delamination state exhibitedby the microstructure of Ti_(2)AlNb hot-rolled plates after heat treatment.The microstructure of samples in both hot-rolled and heat-treated conditions was analyzed using Scanning Electron Microscopy(SEM)and Electron Backscatter Diffraction(EBSD).The hot-rolled plates exhibited a near-equiaxed microstructure similar to recrystallization.Moreover,the proportion of the low-temperature equilibrium phase O-phase exceeded 60%.In the hot-rolled state,the majority of the β-phase and O-phase aligned with the orientation relationship{110}_(β)//{00}_(O),<111>_(β)//<1-10>_(O).Subsequent high-temperature heat treatment led to the transformation of O-phase to the β-phase,while fast cooling retained the β-phase,resulting in noticeable orientation delamination.The texture type of the β-phase exhibited minimal change before and after heat treatment,indicating that the formation of the high-temperature β-phase involves existing β-phase grains from the hot-rolled state growing by engulfing surounding O-phase grains at elevated temperatures.Consequently,the orientation distribution state of the β-phase is kept after phase transformation,leading to a distinctive orientation layer state.The equiaxed microstructure in hot-rolled sheets arises from the high-temperature β-phase transition,and the strong texture of the low-temperature O-phase is inherited from the strong texture of the high-temperature β-phase.These result provide a foundation for our understanding of the Ti_(2)AlNb hot-rolled microstructure and insights for microstructure regulation.
作者
吴俊飞
顾新福
WU Junfei;GU Xinfu(School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China)
出处
《中国体视学与图像分析》
2024年第1期19-28,共10页
Chinese Journal of Stereology and Image Analysis
基金
中央高校基本科研业务费(FRF-TP-20-007A3)。
