Enhancing elongation and trading off strength versus ductility of commercially pure titanium sheets using cyclic bending under tension and annealing
Enhancing elongation and trading off strength versus ductility of commercially pure titanium sheets using cyclic bending under tension and annealing
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DOI：
10.1016/j.ijsolstr.2023.112324
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发表时间：
2023-08
影响因子：
3.6
通讯作者：
Nikolai Matukhno;Nemanja Kljestan;M. Knezevic
中科院分区：
文献类型：
--
作者：
Nikolai Matukhno;Nemanja Kljestan;M. Knezevic
本文描述了在确定循环弯曲-张力（CBT）和退火对提高断裂伸长率（ETF）和优化工业纯钛（cp-Ti）板的强度和延展性的影响的研究中获得的结果。探索了十字头速度和弯曲深度沿着随板厚变化的工艺参数空间，建立了一组最佳工艺参数，使cp-Ti的ETF最大。相对于简单拉伸，使用CBT实现了约3倍的ETF增强。给定由CBT促进的非常大的应变的均匀伸长率，通过使一组片材在优化的参数和退火下经受一定数量的CBT循环来检查材料的强度和延展性的权衡。这样，材料的强度沿片材最软方向增加了沿着，而沿片材最强方向增加了沿着，从而降低了各向异性。微结构的演变，其特征在于使用电子背散射衍射，而纹理演变，使用中子衍射测量。这些结果表明，以滑移为主的变形与孪晶的活动较小。CBT的作用，在保持完整性的片材大塑性应变进行了讨论，通过比较测量和模拟的几何形状和机械领域。
This paper describes results acquired in an investigation into determining the influence of cyclic-bending-under-tension (CBT) and annealing on improving elongation-to-fracture (ETF) and optimizing strength and ductility of commercially pure titanium (cp-Ti) sheets. The space of process parameter involving crosshead velocity and bending depth along with sheet thickness was explored to establish a set of optimal parameters providing the greatest ETF for cp-Ti. Enhancements in ETF of about 3× were achieved using CBT relative to simple tension. Given the uniform elongation facilitated by CBT to very large strains, tradeoffs in strength and ductility of the material were examined by subjecting a set of sheets to a certain number of CBT cycles under the optimized parameters and annealing. In doing so, strength of the material increased by a factor of 1.6 along the sheet softest direction, while by a factor of 1.3 along the sheet strongest direction reducing the anisotropy. Microstructural evolution was characterized using electron-backscattered diffraction, while texture evolution was measured using neutron diffraction. These results revealed slip dominated deformation with minor activity of twinning. The role of CBT in preserving integrity of the sheets to large plastic strains is discussed by comparing measured and simulated geometries and mechanical fields.