Ti-Nb-Ta-Zr-O合金冷变形及再结晶组织

Microstructures of Ti-Nb-Ta-Zr-O alloy deformed and recrystallized

采用电子背散射衍射(EBSD)对Ti-23Nb-0.7Ta-2Zr-1.2O(摩尔分数,%)合金的冷旋锻变形组织和退火组织进行了研究。结果表明:Ti-23Nb-0.7Ta-2Zr-1.2O合金的变形组织中包含高密度的小角晶界,合金具有与棒材轴向平行的强烈<110>丝织构;在退火过程中,合金中的小角晶界密度逐渐降低,大角晶界数量逐渐增多并最终成为主要晶界;在退火过程初期,合金中出现了大量细小晶粒,且随着退火时间的增加,这些晶粒逐渐通过消耗变形组织长大,晶粒取向逐渐分散,表明Ti-23Nb-0.7Ta-2Zr-1.2O合金的再结晶通过传统的形核长大机制进行。

The microstructures of Ti-23Nb-0.7Ta-2Zr-1.2O （mole fraction, %） alloy under cold-swaged and annealed condition were investigated by electron back-scattering electron diffractometry （BSD）. The results show that the microstructures of Ti-23Nb-0.7Ta-2Zr-1.2O alloy deformed contain high density low angle grain boundaries, the alloy has distinctive （110〉 fiber texture paralleling the axial direction of stick. During annealing of the cold-swaged alloy, the low-angle grain boundaries gradually disappear and the high-angle grain boundaries become predominant. At early stage of annealing, the clusters of fine grains appear in the alloy. With the increase of the annealing time, those grains grow gradually at the expense of deformed microstructure. Meanwhile, the orientations of those grains gradually become dispersed, which indicates that the recrystallization of Ti-23Nb-0.7Ta-2Zr-1.2O alloy is achieved by the traditional mechanism of nucleation and growth of new grains.