A Microstructure-based porous crystal plasticity FE Model for additively manufactured Ti-6Al-4V alloys
A Microstructure-based porous crystal plasticity FE Model for additively manufactured Ti-6Al-4V alloys
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DOI：
10.1016/j.ijplas.2022.103254
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发表时间：
2022-03
影响因子：
9.8
通讯作者：
M. Pinz;J. Benzing;A. Pilchak;S. Ghosh
中科院分区：
文献类型：
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作者：
M. Pinz;J. Benzing;A. Pilchak;S. Ghosh
本文在微观组织表征、力学测试、三维统计等效微观组织体积元（SEMVEs）和基于图像的微观组织建模的基础上，建立了具有孔隙度演化的增材制造Ti-6Al-4V合金的有效晶体塑性模型。它们的微观结构以含有12 α板条变体的复杂Widmanstätten形态为特征。在本文中，形态学被统计等效椭球参数化，使得模型中α条的参数化表示成为可能。通过确定α板条与成核母晶β晶粒之间的晶体学关系，并发展了在β晶粒中纳入HCP α板条的统计表示方法，获得了具有α板条形态参数表示的有效晶体塑性框架。β晶粒的本构模型统计地解释了所有12种α板条变体的尺寸、形状、取向和结晶学。一个重要的贡献是孔隙度演化与晶体塑性模型的整合。通过对Ti-6Al-4V合金进行热处理和不热处理实验，验证了模型的正确性。该模型可以对这类相对较新的材料的潜在物理特性产生重要的见解。
Building from a foundation of microstructural characterization, mechanical testing, 3D statistically equivalent microstructural volume elements (SEMVEs), and image-based microstructural modeling, this paper develops an effective crystal plasticity model with porosity evolution for additively manufactured Ti-6Al-4V alloys. Their microstructure is characterized by a complex Widmanstätten morphology containing 12 α lath variants. In this paper, the morphology is parametrized by statistically equivalent ellipsoids, enabling a parametric representation of the α laths in the models. An effective crystal plasticity framework with the parametric representation of the α lath morphology is achieved by identifying the crystallographic relationship of the α laths in relation to the parent β grains from which they have nucleated and developing methods to incorporate a statistical representation of HCP α laths in β grains. The constitutive model for β grains statistically accounts for the size, shape, orientation, and crystallography of all 12 α lath variants. An important contribution is the integration of porosity evolution with the crystal plasticity model. The model is calibrated and satisfactorily validated with results from experiments on additively manufactured Ti-6Al-4V alloys with and without heat treatment. The model can yield important insights into the underlying physics of this relatively new class of materials.