Slip initiation in interlayered β and corresponding slip transfer during compression of a lamellar-structure titanium alloy
Slip initiation in interlayered β and corresponding slip transfer during compression of a lamellar-structure titanium alloy
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DOI：
10.1016/j.rinp.2020.103276
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发表时间：
2020-09-01
影响因子：
5.3
通讯作者：
Liu, Qing
中科院分区：
文献类型：
--
作者：
Wang, Ke;Yan, Zhibing;Liu, Qing
用扫描电子显微镜(SEM)和背向散射电子衍射(EBSD)准原位观察了魏氏组织α/β钛合金压缩过程中四种应变的滑移轨迹和晶体取向。前人的研究表明，由于HCPα相具有较低的屈服强度和较高的杨氏模数，因此滑移总是在层状α相中开始，而在层间β相之前。有趣的是，在这项工作中，发现滑移是在阿尔法菌落内的片层a之前的层间β开始的。同时，在层间应力计算的最大施密德因子(Sf)处，层间β不发生优先滑移。层间β的择优滑移与不同α集团之间的非均匀变形有关，而非均匀变形又与加载方向与α相c轴之间的偏转角θ的分布有关。层间β向层状α的滑移是间接传递的，这不仅需要层间因子与几何兼容参数m‘的良好配合，还需要层间β中大量的变形积累。
The scanning electron microscope (SEM) and electron backscatter diffraction (EBSD) were used for a quasi insitu observation on the slip trace and crystallographic orientation at four strains during the compression of a widmannstatten-structure alpha/beta titanium alloy. The previous investigations suggested that the slip always initiated in lamellar alpha prior to interlayered beta due to the lower yield strength and higher Young's modulus of HCP alpha phase. Interestingly, it is found that the slip initiates in the interlayered beta prior to lamellar a within the alpha colony in this work. Meanwhile, the preferential slip initiation in interlayered beta does not occur at the highest Schmid factor (SF) which is calculated by the applied stress. The preferential slip in interlayered beta is related to the heterogeneous deformation among different alpha colonies, which is related to the distribution of deflection angle theta between loading direction and c-axis of alpha phase. The slip transfers from interlayered beta to lamellar alpha indirectly, which not only requires a good collaboration between SF and geometric compatability parameter (m'), but also needs a large accumulation of deformation in interlayered beta.