Multiscale simulation of grain refinement induced by dynamic recrystallization of Ti6Al4V alloy during high speed machining
Multiscale simulation of grain refinement induced by dynamic recrystallization of Ti6Al4V alloy during high speed machining
复制标题
Ti6Al4V合金高速加工动态再结晶细化晶粒的多尺度模拟
DOI：
10.1016/j.jmatprotec.2020.116834
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发表时间：
2020-12
影响因子：
6.3
通讯作者：
Wanhua Zhao
中科院分区：
文献类型：
--
作者：
Xiang Xu;Jun Zhang;José Outeiro;Binbin Xu;Wanhua Zhao
在高速加工（HSM）过程中，强烈的热力耦合会导致工件变形区的微观结构演化。可能会发生晶粒细化，这对机械行为，甚至对加工表面的疲劳强度和耐腐蚀性能有很大影响。用于预测微观结构演化的多尺度模型的开发越来越受到人们的关注。本研究旨在通过有限元 (FE) 和元胞自动机 (CA) 方法研究 Ti6Al4V 高速加工中动态再结晶 (DRX) 引起的晶粒细化。结合改进的 Johnson-Cook 本构模型 (TANH) 和 Johnson-Mehl-Avrami-Kolmogorov (JMAK) DRX 模型，建立了 Ti6Al4V HSM 的正交切削模型。 CA模型的提出考虑了位错密度演化、晶粒成核和生长。 CA模型成功模拟了二维细观微观结构演化，其中输入变形参数来自正交切削过程的有限元模拟。最后，将通过有限元和CA方法计算的晶粒尺寸和微观结构形貌与通过扫描电子显微镜（SEM）和透射电子显微镜（TEM）实验获得的特征进行比较。在模拟中不考虑孪晶和相变的情况下，CA 和 FE 方法的相同微观结构预测与 TEM 结果相当一致。这项工作证明，有限元和计算机辅助方法的结合是更全面地了解高速加工过程中微观结构演变及其对机械行为影响的有效方法。结果表明，随着切削速度的增加，DRX体积分数和DRX晶粒尺寸的增加最终导致锯齿状切屑的平均晶粒尺寸略有减小，从而导致流变应力的应变软化现象。
During high speed machining (HSM), the strong thermal-mechanical coupling can lead to the microstructure evolution in the deformation zone of workpiece. Grain refinement may occur, which has great effects on the mechanical behavior, and even on the fatigue strength and corrosion resistance of the machined surface. The development of multiscale models to predict the microstructure evolution is gaining rising interest. This study aims to investigate the grain refinement induced by dynamic recrystallization (DRX) occurring in HSM of Ti6Al4V, through finite element (FE) and cellular automata (CA) methods. An orthogonal cutting model for HSM of Ti6Al4V is developed combining a modified Johnson-Cook constitutive model (TANH) and Johnson-Mehl-Avrami-Kolmogorov (JMAK) DRX model. The CA model is proposed considering dislocation density evolution, grain nucleation and growth. The 2D mesoscopic microstructure evolution is simulated successfully by the CA model in which the input deformation parameters come from the FE simulations of the orthogonal cutting process. Finally, the grain size and microstructure morphology calculated by both FE and CA methods are compared with those characteristics obtained experimentally by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Identical microstructure predictions from both CA and FE methods show a reasonable agreement with the TEM results, on the condition that twinning and phase transformation are not considered in the simulations. This work proves that the combination of FE and CA methods is an effective approach to achieve a more comprehensive understanding of the microstructure evolution and its effect on mechanical behavior during HSM. It shows that the rise of both DRX volume fraction and DRX grain size finally results in the slightly decreasing of average grain size of serrated chips with the increase of cutting speed, which leads to the strain softening phenomenon of flow stress.
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DOI：
10.1007/s00170-007-1299-y
发表时间：
2008-12
期刊：
The International Journal of Advanced Manufacturing Technology
影响因子：
--
作者：
J. Davim;C. Maranhão;M. Jackson;G. Cabral;J. Gracio
通讯作者：
J. Davim;C. Maranhão;M. Jackson;G. Cabral;J. Gracio
DOI：
10.1179/msc.1974.8.1.161
发表时间：
1974-01
期刊：
Metal Science
影响因子：
--
作者：
H. Stüwe;B. Ortner
通讯作者：
H. Stüwe;B. Ortner
DOI：
10.1016/j.ijmachtools.2008.03.013
发表时间：
2008-09-01
影响因子：
14
作者：
Mabrouki, Tarek;Girardin, Francois;Rigal, Jean-Francois
通讯作者：
Rigal, Jean-Francois
DOI：
10.1016/j.procir.2017.03.264
发表时间：
2017
期刊：
Procedia CIRP
影响因子：
--
作者：
N. Shen;A. Samanta;Hongtao Ding
通讯作者：
N. Shen;A. Samanta;Hongtao Ding
影响因子：
9.8
作者：
Molinari, A;Musquar, C;Sutter, G
通讯作者：
Sutter, G