GOALI: Collaborative Research: Integrated Computational-Experimental Program for Ductility and Failure in Cast Aluminum Alloys

铸造铝合金延展性和失效的综合计算实验程序 Somnath Ghosh、Bhaskar Majumdar 和 Steve Harris 如今的汽车行业面临着改进的重大挑战，必须提高性能并降低重量比，以便以低成本满足较高的燃油效率和排放标准。 改进的毫安设计变得更加复杂，功率输出要求增加，其延展性和极限强度正在达到实际极限。报废零件和停机时间可能会给制造商造成数百万美元的损失。 复合 拟议的产学合作 GOALI 研究旨在解决这些问题，以实现材料具有高延展性、极限强度和低成本强度的目标。它将在俄亥俄州立大学（PI）、新墨西哥理工学院和福特研究实验室（行业合作伙伴）之间建立合作关系，启动综合实验计算研究项目。该计划将扩大 FRLord 的一个主要推动领域，称为虚拟铝铸造或 VAC，其目标是 (a) 缩短产品开发时间 (b)、提高质量和性能并减少废品，以及 (c) 提高性能并减轻重量，以及 (d) 降低成本。和周期时间。该计划将开发一个经过实验验证的自适应多尺度计算模型系统，用于根据微观结构信息和工艺条件预测铸造铝硅部件的定位和延性断裂。该模型将模拟微观结构特征（例如空隙和第二相）向初期裂纹的演变，并确定延展性损失和延展性失效如何取决于合金性能以及微观结构中不同相的分布和相互作用。将研究颗粒破裂、界面脱聚、基体破裂和通过树枝状网络的损伤渗透的力学。 孔隙大小和分布对失效的作用也将被研究。各种开发模块将包括：(i) 使用 SEM 和定向成像显微镜 (OIM) 进行定量金相学，以及微观结构表征，以识别和表征控制重要材料响应的关键微观结构特征； (ii) 机械测试，并结合原位 SEM 和断裂表面观察、计算机成像和微观结构表征观察，以产生应变场并了解失效过程中的关键机制； ㈢ 用于微应力演化和粒子概率强度估计的中子衍射测量和拉曼微探针技术； (iv) 开发用于多尺度分析的自适应多级模型，以预测作为裂纹多尺度发生和扩展现象的失效过程； (v) 开发基于图像的微观结构 Voronoi Cell 有限元模型，用于高效、准确地分析非均匀异质微观结构中的塑性变形、应变局部化和损伤演化； (vi) 纳入概率分析框架来解释输入变量对延展性和失效的影响。该研究的主要智力优点在于其创新地融合了最先进的计算工具和实验方法，为先进金属材料铸造金属提供了全面的分析工具和设计方法，以提高其有效利用率。这种方法的独特性在于对问题的广泛攻击：（a）引入自适应分层和多尺度计算模型，结合基于图像的微观结构模型来描述不同长度尺度的损伤渗透；。 (b) 通过 PI 开发的高效、准确的 Voronoi Cell 有限元有限元模型，可以在不断变化的损伤和局部化的关键区域结合详细的微观结构。 (c) 通过使用原位 SEM、定向成像显微镜 (OIM)、原位中子衍射和拉曼微探针进行多尺度实验和材料表征的严格反馈，对模型进行稳健验证。据研究人员所知，缺乏这样一种必要的综合方法来理解复杂铸造微观结构的响应和失效特征。 该项目完成后，预计将提供对铸铝复杂相的应力和应变演变、强度水平以及脆性、延性和多孔相网络的损伤萌生和渗透的良好理解。 该计划的更广泛影响将体现在两个方面。 首先，它将超越汽车行业，帮助整个铸造行业，在铸造行业，合金化和凝固技术的显着进步常常受到未知因素的阻碍，因为不知道材料和工艺参数的变化如何影响损伤容限和延展性。 该方法将使工业界能够超越现有技术，并将这些轻质合金用于新的安全关键应用，并了解现在可以以合理的置信度预测延展性和断裂性。第二条战线是每年夏天研究生将在 FRL 实习，NMT 学生将有机会使用国家实验室的设备。作为大学与工业界合作的结果，该项目的学生将与工业研究人员进行强有力的互动并获得工业研究人员的指导。学生还将与桑迪亚国家实验室的研究人员进行互动。 研究人员。 此外，国家实验室也将参与该工作的实验部分。

Integrated computational- experimental program for ductility and failure in cast aluminum alloys Somnath Ghosh, Bhaskar Majumdar and Steve Harris Today's The automotive industry is faced with major challenge of improvedmustis faced with major challenges to improve performance to and reduce weight ratio in order to meet lofty fuel efficiency and emissions standards at low cost. Improved mAs designs become more complex and the power output requirements increase, the practical limits of their ductility and ultimate strength are being reached.,. which Scrapped parts and downtime can cost a manufacturer millions of dollars in terms of scrapped parts and downtime. Compounding The proposed Industry-University Collaborative GOALI research is aimed at addressing thisese issues for meeting goals of materials with high ductility, ultimate strength and strength at low cost. It will build a collaborative relation between the Ohio State University (PI), New Mexico Institute of Technology and Ford Research Laboratory (industry partner) to launch an integrated experimental-computational research program. The program will augment a major thrust area at FRLord called Virtual Aluminum Casting or VAC that is targeted to (a) reduce product development time (b), improve quality and performance, and reduce scrap and (c) improve performance and lower weight, and (d) reduce costs. and cycle time. The proposed program will develop a system of experimentally validated adaptive multiple scale computational models for predicting localization and ductile fracture of cast Al-Si components from microstructural information and process conditions. The models will simulate the evolution of microstructural features such as voids and secondary phases into incipient cracks and determine how the loss of ductilityductile failure depends on alloy properties and on the , distributions and interactions of different phases in the microstructure. The mechanics of particle fracture, interface decohesion, matrix rupture and damage percolation through the dendritic network will be studied. The role of porosity size and distribution on failure will also be investigated. Various dDevelopmental modules will include: (i) Quantitative metallography using SEM, and orientation imaging microscopy (OIM), and microstructural characterization to identify and characterize critical microstructure features that control important material response; (ii) Mechanical tests accompanied bywith in-situ SEM and fracture surface observations, computer imaging and microstructural characterization observation to generate strain fields and to provide understanding of critical mechanisms in the failure process; (iii) Neutron diffraction measurements and Raman microprobe techniques for microstress evolution and probabilistic strength estimation of particles; (iv) Development of an adaptive multi-level model for multiple scale analysis to predict the failure process as a phenomenon of multi-scale incidence and propagation of cracks; (v) Development of image-based microstructural Voronoi Cell finite element model for efficient and accurate analysis of plastic deformation, strain localization and damage evolution in nonuniform heterogeneous microstructures; and (vi) Incorporation of a probabilistic analysis framework to account for the effect of input variabilities on ductility and failure. The major intellectual merit of the proposed research is in its innovative blend of state state-of of-the the-art computational tools andwith experimental methods to advance provide a comprehensive analysis tool and design methodology for advanced metallic materialscast metals to increase their effective utilization. The uniqueness of this approach is in the broad attack on the problem: (a) iIntroduction of adaptive hierarchical and multi-scale computational models, incorporating image-based microstructural models to depict the percolation of damage at different length scales;. T (b) he iIncorporation of detailed microstructures at the critical regions of evolving damage and localization is possible through the efficient and accurate Voronoi Cell finite elementFE model, being developed by the PI.; and (c) Robust validation of the models through rigorous feedback from multi-scale experiments and material characterization by using in-situ SEM, orientation imaging microscopy (OIM), in-situ neutron diffraction and Raman microprobe. To the best knowledge of the investigators, there is a lack of such a necessary comprehensive approach to the understanding of response and failure characteristics of complex cast microstructures. The program, upon completion, is expected towill provide a good understanding of stress and strain evolution ofin the the complex phases in cast Al, their strength levels, and damage initiation and percolation through the network of brittle, ductile and porous phases. The broader impact of the program will occur on two fronts. front, the It will reach beyond the automotive industry to aid the entire casting industry, where significant gains in alloying and solidification technology is are often stymied by unknowns regardingnot knowing how variability in material and process parameters affect damage tolerance and ductility. The methodology will allow industry be able to leapfrog thepresent technology and use these lightweight allows into in new safety -critical applications, armed with the knowledge that ductility and fracture can now be predicted with a reasonable degree of confidence. The second front will be oGraduate students will intern at FRL every summer and NMT students will have access to equipment at the national labs. As a consequence of the university-industry collaboration collaboration, students in this program will have a strong interaction with and mentorship from industrial researchers . There will also be student interaction with researchers at Sandia National Laboratory. researchers. In addition, the national laboratories will be involved in the experimental component of the work.