Strain heterogeneity and damage nucleation at grain boundaries during monotonic deformation in commercial purity titanium
Strain heterogeneity and damage nucleation at grain boundaries during monotonic deformation in commercial purity titanium
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DOI：
10.1007/s11837-009-0180-x
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发表时间：
2009
期刊：
影响因子：
2.6
通讯作者：
T. Bieler;M. Crimp;Y. Yang;L. Wang;P. Eisenlohr;D. E. Mason;W. Liu;G. Ice
中科院分区：
文献类型：
--
作者：
T. Bieler;M. Crimp;Y. Yang;L. Wang;P. Eisenlohr;D. E. Mason;W. Liu;G. Ice
使用许多实验技术分析了多晶商业纯钛的非均匀应变，这些实验技术提供了有关微观结构、位错排列、晶粒取向、取向梯度、表面形貌和局部应变梯度的信息。使用4点弯曲至2%至15%之间的应变，在变形前后对具有50-200 µm晶粒的再结晶显微组织进行了广泛表征。沿沿着某些晶界发生极不均匀的变形，导致在10-20 µm范围内的取向梯度超过10°。利用晶体塑性有限元（CPFE）分析对高度特征化的微结构进行建模，以模拟变形，从而评估CPFE模型捕获局部变形过程的能力。损伤成核事件被确定与孪晶与晶界的相互作用。基于滑移和孪晶与晶界的相互作用确定断裂起始准则的进展与TiAl合金中变形的相关CPFE模拟说明。
Heterogeneous strain was analyzed in polycrystalline, commercial-purity titanium using many experimental techniques that provide information about microstructure, dislocation arrangement, grain orientation, orientation gradients, surface topography, and local strain gradients. The recrystallized microstructure with 50–200 µm grains was extensively characterized before and after deformation using 4-point bending to strains between 2% and 15%. Extremely heterogeneous deformation occurred along some grain boundaries, leading to orientation gradients exceeding 10° over 10–20 µm. Patches of highly characterized micro-structure were modeled using crystal plasticity finite element (CPFE) analysis to simulate the deformation to evaluate the ability of the CPFE model to capture local deformation processes. Damage nucleation events were identified that are associated with twin interactions with grain boundaries. Progress toward identifying fracture initiation criteria based upon slip and twin interactions with grain boundaries is illustrated with related CPFE simulations of deformation in a TiAl alloy.