个人信息Personal Information
性别：男
学科：力学. 航空宇航科学与技术. 材料科学与工程. 机械工程. 冶金工程. 先进制造. 航空工程. 材料工程. 冶金工程. 机械工程. 固体力学
多尺度力学，宏微观力学，梯度结构材料，界面力学，固体本构关系，应变梯度理论，晶体塑性有限元，离散位错动力学，分子动力学，高熵合金，大数据与机器学习，材料基因，极端力学，高性能材料，材料的增强与增韧
2020-02-24 陆晓翀（博士生）的论文“Crystal plasticity finite element analysis of gradient nanostructured TWIP steel”在期刊 International Journal of Plasticity 上在线发表。
发布时间：2020-02-24
Highlights
•A physically based size-dependent crystal plasticity model for twinning induced plasticity (TWIP) steels is developed.
•A thermodynamical framework of stacking fault energy (SFE) calculation is developed for Fe-Mn-C-Ni steel system.
•Simulations successfully reveal the microstructure-property relation of the gradient nanostructured (GNS) TWIP steel.
•The individual contribution of each gradient microstructure to overall mechanical properties is quantified.
Abstract
Although twinning induced plasticity (TWIP) steels have achieved a satisfactory combination of high strength and large plasticity, surface nanocrystallization realizes a further improvement of yield stress in TWIP steels without sacrificing much ductility via gradient microstructures. Experimental investigations have already revealed the excellent mechanical properties and deformation mechanisms of the gradient nanostructured (GNS) TWIP steels. But the prediction and optimization of their mechanical properties are limited due to the lack of a constitutive model. Here we establish a size-dependent crystal plasticity model containing dislocation slipping and deformation twinning, which can describe the tensile response of TWIP steels with different grain sizes. After that, this model is applied to simulate the tensile deformation behavior of the GNS TWIP steel with three kinds of gradient microstructures, namely gradient grain size, dislocation density and twin fraction. The modeling predictions are in agreement with the existing experimental data. Through the analysis of deformation contours and microstructural evolutions, the intrinsic reason for the balance of strength and ductility in the GNS TWIP steel is discussed, and the contribution of each gradient microstructure is quantized. It is found that the surface gradient region containing fine grains, high densities of dislocations and twins improves the yield stress. The homogeneous region in the core helps maintain the strain hardening ability, but the gradient region has lower strain hardening ability, which causes surface notches and slight loss of the ductility. This study offers valuable insights into predicting and further optimizing the mechanical behavior of GNS materials.
Link
https://doi.org/10.1016/j.ijplas.2020.102703