Efficient computational framework for image-based micromechanical analysis of additively manufactured Ti-6Al-4V alloy
Efficient computational framework for image-based micromechanical analysis of additively manufactured Ti-6Al-4V alloy
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DOI：
10.1016/j.addma.2022.103269
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发表时间：
2022-11
影响因子：
11
通讯作者：
M. Pinz;S. Storck;T. Montalbano;B. Croom;N. Salahudin;M. Trexler;S. Ghosh
中科院分区：
文献类型：
--
作者：
M. Pinz;S. Storck;T. Montalbano;B. Croom;N. Salahudin;M. Trexler;S. Ghosh
随着高性能工业应用中增材制造（AM）Ti-6Al-4V合金的增加，有必要开发强大的计算模型，以帮助其鉴定和认证。基于物理的微观力学模型将AM处理的材料微观结构和缺陷状态与整体材料响应和寿命联系起来，可以在减少组件行为的不确定性和提高接受度方面发挥重要作用。出于这一需求，本文开发了一种新的基于图像的晶体塑性有限元模型（CPFEM），用于增材制造的Ti-6Al-4V合金的有效微观力学模拟，其魏氏组织的特征在于母β晶粒中的12个HCP α板条变体。这项工作的一个独特之处是为母体β晶粒多晶系综创建了一个有效的晶体塑性框架，该框架具有尺寸、形状、取向和晶体学的α板条统计的参数表示。与在微观结构中明确表示每个α板条的模型相比，这种统计表示预计将显著提高其效率。空隙形式的缺陷以两种尺度表示。在晶体塑性模型中，微观结构中较小的孔隙表现为孔隙率或孔隙体积分数分布。更大的空隙表示明确的统计等效微观结构体积元（SEMVE）模型。该模型建立从实验获得的电子背散射衍射（EBSD）和微焦点X射线计算机断层扫描（XCT）图像和校准和验证与机械测试数据。本文扩展了Pinz等人的发展。（2022）通过在并发模型的背景下开发特殊的自洽边界条件来克服周期性边界条件的限制。并行模型将SEMVE嵌入到由率相关各向同性塑性模型表示的均匀化外部域中。进行参数研究，以了解整体材料响应上的空隙尺寸，形状和方向的效果。
The increase in additively manufactured (AM) Ti-6Al-4V alloys in high-performance industrial applications has necessitated the development of robust computational models that can aid in their qualification and certification. Physics-based micromechanical models, relating the AM-processed material microstructure and defect state with the overall material response and life, can play an important role in reducing uncertainty in component behavior and increasing acceptance. Motivated by this need, the present paper develops a novel image-based crystal plasticity finite element model (CPFEM) for efficient micromechanical simulation of the additively manufactured Ti-6Al-4V alloy, whose Widmanstätten microstructure is characterized by 12 HCP α lath variants in the parent β grain. A unique feature of this work is the creation of an efficient crystal plasticity framework for the parent β grain polycrystalline ensembles with parametric representation of the α lath statistics of size, shape, orientation, and crystallography. This statistical representation is expected to significantly enhance its efficiency over models that represent each α lath explicitly in the microstructure. Defects in the form of voids are represented at two scales. The smaller voids in the microstructure are manifested as porosity or void volume fraction distribution in the crystal plasticity model. Larger voids are represented explicitly in the statistically equivalent microstructural volume element (SEMVE) model. The models are built from experimentally acquired electron back scatter diffraction (EBSD) and micro-focus X-ray computed tomography (XCT) images and calibrated and validated with mechanical testing data. This paper extends the developments in Pinz et al.(2022) through the development of a special self-consistent boundary condition in the context of a concurrent model to overcome limitations of periodicity boundary conditions. The concurrent model embeds the SEMVE in a homogenized exterior domain represented by a rate-dependent isotropic plasticity model. Parametric studies are conducted to comprehend the effect of void size, shape and orientation on the overall material response.