Texture Evolution and Softening During Discontinuous Dynamic Recrystallization

不连续动态再结晶过程中的织构演变和软化

• 批准号: 1662646
• 负责人: Stephen Niezgoda
• 金额: $ 41.58万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1662646&HistoricalAwards=false
• 关键词: Texture; Evolution; Softening; During; Discontinuous

Metals are enablers of numerous advanced engineering designs that require high strength and toughness, and remain irreplaceable for key components in structural applications in aviation, transportation, power generation, etc. The mechanical properties of engineering metals are closely related to their internal microstructure, which is obtained and optimized through thermal and mechanical processing. However, the processing-microstructure relationship is still poorly understood, which severely limits the prospect of direct one-step microstructure engineering. This award supports an integrated computational and experimental study to establish a quantitative physics-based model that will be used to explore the fundamental mechanisms that control microstructure evolution during hot working. The model will have the ability to assist in the design and optimization of thermomechanical processes for many engineering alloys including nickel-based superalloys for high temperature applications and magnesium-alloys for light structural applications. The PIs are committed to support an undergraduate research program as well as an existing university program that engages undergraduate researchers as mentors who develop K-12 engineering outreach activities under the guidance of K-12 educators.Dynamic recrystallization (DRX) involves the nucleation and growth of new grains during straining at elevated temperatures and plays a critical role in controlling microstructure changes during thermomechanical processing (TMP). Nevertheless, many aspects of DRX remain poorly understood, with the lack of both fundamental knowledge and predictive physics-based models for the evolution of dislocation density, grain structure and texture and the corresponding effects on the macroscopic stress-strain response. This award supports an integrated computational and experimental study that will first establish a full-field DRX model by dynamically coupling a phase-field recrystallization model with a fast Fourier transform crystal plasticity model. Then the model will be used to investigate the following central hypothesis on DRX: The orientation of newly nucleated grains and the degree of subsequent softening are direct consequences of the long-range, inter-granular stress field resulting from plastic anisotropy and the dislocation structure evolution near grain boundaries. In addition to the traditional bulging mechanism, a new DRX nucleation mechanism that selects orientations for easy elastic or plastic deformation will be tested. The computational model established in this project will be directly applicable to many important engineering alloys such as nickel-base superalloys and magnesium-alloys during TMP. The processing-texture-property relationship established in this research will improve the fundamental understanding of the interplay between microstructural and micromechanical fields during DRX and may lead to better optimization of industrial processing.

金属是需要高强度和韧性的众多先进工程设计的推动者，并且仍然是航空，运输，发电等结构应用中的关键组件的不可替代的。工程金属的机械性能与其内部微观结构密切相关，其内部微观结构是通过热和机械处理获得和优化的。但是，处理微观结构的关系仍然鲜为人知，这严重限制了直接一步微观结构工程的前景。该奖项支持一项集成的计算和实验研究，以建立一个基于定量物理的模型，该模型将用于探索在热工作过程中控制微观结构演变的基本机制。该模型将有能力为许多工程合金（包括基于镍的高温应用和镁合金）的热机械工艺设计和优化，用于轻型结构应用。 PI致力于支持本科研究计划以及现有的大学计划，该计划将本科研究人员作为指导者，他们在K-112教育工作者的指导下开发K-12工程宣传活动。DYNAGINICRECRYSTALLIANS（DRX）涉及在高度机器机器机器机器机器机器机器机器机器机器机器上的核能和对控制过程中的紧张过程中的新谷物的成核和成长。然而，由于缺乏基本知识和基于预测性物理学的模型，DRX的许多方面仍然尚不清楚，用于脱位密度，晶粒结构和纹理的演变以及对宏观应激构成响应的相应影响。该奖项支持一项集成的计算和实验研究，该研究将通过将相位场重结晶模型与快速傅立叶变换晶体可塑性模型动态耦合，首先建立全场DRX模型。然后，该模型将用于研究DRX上的以下中心假设：新成核晶粒的方向和随后的软化程度是塑料各向异性和晶界接近晶界的脱位结构演变导致的远距离，粒间应力场的直接后果。除了传统的膨胀机制外，还将测试一种新的DRX成核机制，以选择方向易弹性或塑性变形。该项目中建立的计算模型将直接适用于许多重要的工程合金，例如TMP期间的镍基超合金和镁合金。这项研究中建立的处理 - 纹状体关系将改善对DRX过程中微观结构和微机械场之间相互作用的基本理解，并可能会更好地优化工业处理。

项目成果

Comparison of full field predictions of crystal plasticity simulations using the Voce and the dislocation density based hardening laws

• DOI: 10.1016/j.ijplas.2021.103099
• 发表时间: 2021-09
• 期刊: International Journal of Plasticity
• 影响因子: 9.8
• 作者: C. Patil;Supriyo Chakraborty;S. Niezgoda

Supersolvus Hot Workability and Dynamic Recrystallization in Wrought Co–Al–W-Base Alloys.

变形钴铝钨基合金的超溶线热加工性和动态再结晶。

• DOI: 10.1007/978-3-030-51834-9_84
• 发表时间: 2020
• 期刊: Superalloys 2020
• 作者: Wertz, K.;Weaver, D.;Wen, D.;Titus, M.S.;Shivpuri, R.;Niezgoda, S.R.;Mills, M.J.;Semiatin, S.L.
• 通讯作者: Semiatin, S.L.

Finite strain phase-field microelasticity theory for modeling microstructural evolution

• DOI: 10.1016/j.actamat.2020.03.033
• 发表时间: 2020-06
• 期刊: Acta Materialia
• 影响因子: 9.4
• 作者: P. Zhao;T. Low;Yunzhi Wang;S. Niezgoda

Microstructural and micromechanical evolution during dynamic recrystallization

• DOI: 10.1016/j.ijplas.2017.09.009
• 发表时间: 2018
• 期刊: International Journal of Plasticity
• 影响因子: 9.8
• 作者: P. Zhao;Yunzhi Wang;S. Niezgoda