Isothermal deformation and spheroidization mechanism of (TiB + La 2 O 3 )/Ti composites with different initial structures
Isothermal deformation and spheroidization mechanism of (TiB + La 2 O 3 )/Ti composites with different initial structures
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不同初始结构(TiB La 2 O 3 )/Ti复合材料的等温变形及球化机理
DOI：
10.1016/j.matchar.2018.09.040
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发表时间：
2018
影响因子：
4.7
通讯作者：
Weijie Lu
中科院分区：
文献类型：
--
作者：
Pinwang Liu;Yuanfei Han;Peikun Qiu;Fushun Xu;Yue Chen;Lihua Du;Guangfa Huang;Jianwei Mao;Weijie Lu
通过设计的热处理工艺，获得了不同初始组织的(TiB、 + 、La_2O_3)/Ti复合材料。研究了不同初始组织的(TiB、 + 、La_2O_3)/Ti复合材料的等温变形和球化机制。随着热处理温度的降低，初始组织细化。同时，与炉内冷却相比，淬火和再加热产生了更细小的α片层集落和α片层间距。在流动应力数据方面，炉冷样品的流动阻力低于淬火和再加热样品。在920 °C变形后，炉冷样品呈片状α相和部分球化组织。此外，球化机制类似于边界分裂模型。在920 μ°C变形后的淬火和再加热样品中获得了直径约为1 m的再结晶组织，球化机制归因于通过淬火和再加热形成更细小的针状物，以及随后的热变形动态再结晶。此外，由于复合材料中含有微米级TiB和亚微米级La_2O_3，增强体在热变形过程中阻碍了位错的运动。此外，增强体还能促进α相的动态再结晶。
(TiB + La2O3)/Ti composites with different initial structures were obtained through designed heat treatment. The isothermal deformation and spheroidization mechanisms of (TiB + La2O3)/Ti composites with different initial structures were investigated. Initial structures were refined as the heat treatment temperature decreased. Simultaneously, the quenching and reheating resulted in finer α lamella colonies and α interlamellar spacing compared to the furnace cooling. The flow resistance of furnace cooled samples was lower than the quenched and reheated samples in terms of flow stress data. Following the deformation at 920 °C, the furnace cooled samples demonstrated lamellar α phase and partial spheroidized structure. Moreover, the spheroidization mechanism was similar to the boundary splitting model. Recrystallized grains of approximately 1 μm in diameter were obtained in the quenched and reheated sample following deformation at 920 °C. The spheroidization mechanism was attributed to the development of finer needles through quenching and reheating, as well as to subsequent dynamic recrystallization during the hot deformation. Additionally, the dislocation movement was blocked by the reinforcements on account of the composites with micron TiB and submicron La2O3during the hot deformation. Furthermore, the reinforcements could facilitate the dynamic recrystallization (DRX) of the α phase.