DMREF: Collaborative Research: GOALI: Localized Phase Transformation (LPT) Strengthening for Next-Generation Superalloys

这一设计材料以革命和工程我们的未来（DMREF）资助机会与工业学术联络（GOALI）奖支持综合实验和计算工作，以加速发现新型镍基高温合金，这些合金将具有上级高温蠕变性能，但很可能会被传统的试错法错过。镍基高温合金是关键的高温结构材料，决定了各种航空航天和陆基发电系统（如燃气轮机）的效率和碳足迹。这项工作是材料基因组计划（MGI）和综合计算材料工程（ICME）计划下的国家工作的一个组成部分。这是第一次，高温合金的开发将由计算建模主导，通过关键实验进行机械信息和验证，涉及材料加工的新型组合方法和最先进的表征技术。由于未来的材料研发活动，需要大大减少时间和成本周期，必须将计算材料研究与关键实验相结合，这个研究项目将直接准备研究生立即为MGI/ICME在工业中的成功做出贡献。此外，为参与材料开发的研究人员提供的培训计划将加速新方法在工业中的实施，从而提高美国材料技术专家的效率。关于教育推广，目前的DMREF计划将聘请本科研究人员作为导师，他们开发K-12工程推广活动，鼓励具有不同种族背景的高中生进入科学和工程学科。DMREF GOALI项目将利用一种新的设计策略，利用局部相变（LPT）现象来破坏性地改善镍基高温合金的高温蠕变性能。LPT仅发生在扩展缺陷处，并局限于这些缺陷处。通过整合复杂的计算模型，在多个尺度上，高度先进的材料表征技术，以及材料加工和性能评估的组合和加速方法，该项目将（a）通过高通量DFT Monte Carlo计算搜索LPT发生的高维合金成分空间，并通过新颖的组合方法验证DFT预测以快速生产合金，结合先进的电子显微镜和原子探针断层扫描;（B）建立缺陷类型之间的联系（堆垛层错，反相界，孪晶，位错及其网络）和LPT的性质，使用DFT计算作为输入的相场模拟;（c）定量地确定LPT对操作变形机制的影响，并开发物理学-基于变形模型，使用相场方法和机制敏感的晶体塑性模型的组合来捕获这些效应，这将使多晶蠕变实验直接验证;以及（d）采用新的加工路线以通过LPT稳定高位错/孪晶密度微结构，从而提供用于部署到超合金的新的强化机制。该项目的GOALI合作伙伴GE Research将通过提供单晶和多晶形式的高质量合金来响应合金建议。这种综合性的研究工作将大大提高新的高温合金的发现和开发的最新技术水平，并有望在合金设计中产生新的科学。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Extraordinary Properties This Designing Materials to Revolutionize and Engineer our Future (DMREF) Grant Opportunity for Academic Liaison with Industry (GOALI) award supports an integrated experimental and computational effort to accelerate the discovery of new typs of Ni-base superalloys that will have superior high-temperature creep performance, but most likely will have been missed by the traditional trial-and-error method. Ni-base superalloys are critical enabling high-temperature structural materials that determine the efficiency and carbon footprint of a wide range of aerospace and land-based power generation systems such as gas turbines. This effort is an integral part of the national efforts under the Materials Genome Initiative (MGI) and the Integrated Computational Materials Engineering (ICME) initiative. For the first time, superalloy development will be led by computational modeling, mechanistically informed and validated by critical experiments involving novel combinatorial methods for materials processing and state-of-the-art characterization techniques. Because future materials R&D activities, requiring substantially reduced time and cost cycles, must integrate computational materials research with critical experiments, this research project will directly prepare graduate students to immediately contribute to the success of MGI/ICME in industry. Additionally, the training programs for researchers involved in materials development will accelerate the implementation of the new methodology in industry, resulting in increased effectiveness of the US materials technologists. Regarding educational outreach, the present DMREF program will engage undergraduate researchers as mentors who develop K-12 engineering outreach activities encouraging high school students with diverse ethnic backgrounds to enter science and engineering disciplines This DMREF GOALI project will exploit a new design strategy that utilizes a localized phase transformation (LPT) phenomenon to disruptively improve the high-temperature creep performance of Ni-based superalloys. LPTs occur only at extended defects and are confined locally at these defects. By integrating sophisticated computational models, at multiple scales, highly advanced materials characterization techniques, and combinatorial and accelerated methods of materials processing and property evaluation, this project will (a) search the high-dimensional alloy composition space for the occurrence of LPT by high-throughput DFT Monte Carlo calculations, and validate the DFT predictions by novel combinatorial methods to rapidly produce alloys, coupled with advanced electron microscopy and atom probe tomography; (b) establish the connection between defect type (stacking fault, anti-phase boundaries, twins, dislocations and their networks) and the nature of LPT using phase field simulations with the DFT calculations as inputs; (c) quantitatively determine the effect of LPT on the operative deformation mechanisms and develop physics-based deformation models that capture these effects using a combination of the phase field method and a mechanism-sensitive crystal plasticity model, which will enable direct validation against polycrystalline creep experiments; and (d) employ novel processing routes to stabilize high dislocation/twin density microstructures by LPT, thereby providing a new strengthening mechanism for deployment to superalloys. The GOALI partner of this project, GE Research, will respond to alloy recommendations by providing high quality alloys in single crystal and polycrystal forms. Such an integrated research effort will raise significantly the state-of-the-art in the discovery and development of new superalloys and is expected to result in new science in alloy design. The focus on superalloys will have a marked impact on a broad range of advanced technological areas including aerospace, transportation and energy.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.