Electro-plasticity in Al-Cu eutectic alloys

SPP“由电场和磁场控制的物质操纵：无机材料的新型合成和加工路线”中的这一提案的最终目的是解开一些潜在的机制，这些机制有助于在其他脆性材料的机电变形过程中增强塑性。为此，一个集成的计算材料工程（ICME）的方法是追求耦合一系列的表征技术与机制为基础的多尺度模拟铝铜共晶合金。更好地了解这些合金中的电塑性效应，可以为更一般的金属-金属间化合物复合材料提供新的加工路线，从而拓宽这类多功能材料的技术应用。为了提高铸造Al-Cu共晶合金的强度和成形性，对Al-Cu共晶合金的电-机械变形行为进行了实验和理论研究。具体而言，我们将使用快速合金原型法合成具有不同微观结构的Al-Cu合金，并表征其机电行为。此外，在原位微尺度电塑性实验，使用纳米压痕和微柱压缩将进行阐明的电塑性效应在不同的微观结构成分的影响。将使用扫描电子显微镜、常规和高分辨率透射电子显微镜和原子探针断层扫描进行介观和微尺度微观结构表征，以研究电塑性效应的局部微观结构影响，并将其与宏观机械性能相关联。所有的实验数据将被用作输入和验证参数的电塑性效应的多尺度模拟。在这里，由Conrad等人开发的电子风对塑性应变率的贡献的本构理论将首先用于适应现有的晶体塑性本构关系。还将考虑其他因素，如焦耳加热及其对热膨胀和软化的影响。计算实现将在灵活的模拟工具包DAMASK中进行，并将被应用于研究与Al-Cu合金的底层微观结构相关的机电变形机制。

The ultimate aim of this proposal within the SPP 'Manipulation of Matter Controlled by Electric and Magnetic Fields: Towards Novel Synthesis and Processing Routes of Inorganic Materials' is to unravel some of the underlying mechanisms facilitating enhanced plasticity during electro-mechanical deformation in otherwise brittle materials. To this end, an integrated computational materials engineering (ICME) approach is pursued by coupling a range of characterization techniques with mechanism-based multi-scale simulations in Al-Cu eutectic alloys. A better understanding of the electro-plastic effect in these alloys enables novel processing routes for more general metallic-intermetallic composite materials and thereby widening the technological application of this versatile class of materials. Complementary experimental and theoretical investigations of the electro-mechanical deformation behaviour of Al-Cu eutectic alloys are proposed with the aim to enhance the strength and formability of cast Al-Cu eutectic alloys. Specifically, we will synthesize Al-Cu alloys with varying microstructures using rapid alloy prototyping and characterize their electro-mechanical behaviour. Further, in-situ microscale electro-plasticity experiments using nano-indentation and micropillar compression will be performed to shed light on the influence of the electro-plastic effect in the different microstructural constituents. Meso- and microscale microstructure characterization using scanning electron microscopy, conventional and high resolution transmission electron microscopy, and atom probe tomography will be performed to investigate the local microstructural influence of the electro-plastic effect and correlate it with the macroscopic mechanical properties. All experimental data will be used as input and validation parameters for multi-scale simulations of the electro-plastic effect. Here the constitutive theory developed by Conrad et al. for the electron wind contribution to the plastic strain-rate will initially be used to adapt existing crystal plasticity constitutive laws. Additional factors such as joule heating and its effect on thermal expansion and softening will also be considered. The computational implementation will be performed within the flexible simulation toolkit DAMASK, and will be applied to study the electro-mechanical deformation mechanisms in relation to the underlying microstructure of the Al-Cu alloys.