Evaluation of the jogged-screw model of creep in equiaxed γ-TiAl: identification of the key substructural parameters
Evaluation of the jogged-screw model of creep in equiaxed γ-TiAl: identification of the key substructural parameters
复制标题
等轴 γ-TiAl 蠕变螺旋模型的评估：关键子结构参数的识别
DOI：
10.1016/j.actamat.2004.02.006
复制
发表时间：
2004
期刊：
影响因子：
9.4
通讯作者：
M. Mills
中科院分区：
文献类型：
--
作者：
S. Karthikeyan;G. Viswanathan;M. Mills
根据对1/2[110]型错齿螺位错显微结构的观察，提出了等轴γ-Ti-48 Al合金蠕变变形机制是由错齿的攀移控制的。这是验证的预测蠕变模型的基础上，这些意见。然而，模型中的几个假设并没有得到实验或理论的充分证实。本研究的目的是验证和验证模型中假设的参数和功能依赖关系。此外，原来的解决方案已重新制定，以考虑到有限的高度移动慢跑。在此基础上，进一步研究了子结构模型参数。通过模拟、分析建模和实验观察，评估了位错密度、慢跑间距和慢跑高度的应力依赖性。将所有这些参数和依赖关系结合在一个重新制定的模型中，可以很好地预测蠕变速率和应力指数。
On the basis of microstructural observation of 1/2[110]-type jogged-screw dislocations, it has been previously proposed that the creep deformation mechanism in equiaxed γ-Ti–48Al alloys is controlled by the climb of the jogs on these dislocations. This is validated by predictions from a creep model based on these observations. However, several assumptions made in the model were not fully substantiated by experiment or theory. The aim of this study is to verify and validate the parameters and functional dependencies assumed in the model. In addition, the original solution has been reformulated to take into account the finite height of the moving jog. The substructural model parameters have been further investigated in light of this reformulation. The stress dependence of dislocation density, jog spacing and jog height has been evaluated via simulations, analytical modeling and experimental observations. Combining all of these parameters and dependencies in a reformulated model leads to an excellent prediction of creep rates and stress exponents.