Putting Atoms Where they are Needed: Segregation for Property Control in Structural Alloys

将原子放在需要的地方：结构合金中财产控制的偏析

• 批准号: RGPIN-2017-04677
• 负责人: Sinclair, Chad
• 金额: $ 2.7万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=665271
• 关键词: Putting; Atoms; Where; they; Needed

*** From cars to integrated circuits, engineers locate different materials to best exploit their unique properties. It may seem odd then, that the production of structural alloys rarely employs this same optimized strategy. Despite the strong chemistry dependence of many material properties, alloys are typically designed by correlating properties to average chemistry. Recognizing this as an opportunity, our group is at the leading edge of a movement whose aim is to develop emerging processing techniques aided by advanced characterization and simulation tools to ‘put atoms where they are needed' in engineering alloys. This is providing breakthroughs in new product development by, for example, using the natural tendency of strengthening atoms to migrate to ‘weak' points in a material. Beyond the potential for new freedom in property design, such a chemically site-specific strategy offers a more efficient use of expensive and/or difficult to source alloying elements at a time where resource availability is an increasingly important consideration.*** To achieve such site-specific chemistry and property control one can harness the natural tendency of chemical species to segregate to interfaces (internal or external) in metals. Applying this approach, recently coined ‘segregation engineering', self-healing steels, improved conversion efficiency for low cost solar cells and photonic metallic nanostructures have been developed in the past 5 years. *** A bottleneck for the development of future technologies via this route is our reliance on continuum models that are blind to the inherently atomistic structure of alloy interfaces. This lack of predictive sophistication slows development and risks missing novel solutions existing outside of current model calibrations. While current atomistic models are valuable for structure-property relationships in perfect crystals, none are well suited for alloy segregation where atomistic length-scales and diffusional timescales must be resolved for multicomponent chemistries. *** This proposal seeks to fill the gap by deploying a new model, recently pioneered by our group, particularly designed for the prediction of segregation to alloy interfaces and defects. Integrating this model with an experimental program, we will map the segregation strengthening potential of alloying elements at interfaces and unravel the fundamental processes that control interfacial phase transitions and morphological instabilities. The ultimate goal is to deploy this strategy to revolutionize next generation high strength, lightweight structural alloys with surface driven functionality using the fundamentally guided interface structure-property relationships developed as part of this proposal.

*** 从汽车到集成电路，工程师们寻找不同的材料，以最好地利用其独特的性能。 那么，结构合金的生产很少采用这种相同的优化策略似乎很奇怪。 尽管许多材料的性质具有很强的化学依赖性，但合金通常是通过将性质与平均化学性质相关联来设计的。 认识到这是一个机会，我们的团队处于一个运动的前沿，其目标是开发新兴的加工技术，辅以先进的表征和模拟工具，在工程合金中“将原子放在需要的地方”。 这为新产品开发提供了突破，例如，利用强化原子迁移到材料中“薄弱”点的自然趋势。 除了在属性设计方面的新自由度的潜力之外，这种化学上针对特定地点的策略在资源可用性越来越重要的考虑因素的时候提供了对昂贵和/或难以获得的合金元素的更有效的使用。 为了实现这种特定位点的化学和性质控制，人们可以利用化学物质分离到金属界面（内部或外部）的自然趋势。 应用这种方法，最近创造的“隔离工程”，自修复钢，提高转换效率的低成本太阳能电池和光子金属纳米结构在过去5年中已经开发出来。 *** 通过这条路线的未来技术的发展的瓶颈是我们依赖于连续模型，是盲目的合金界面的固有原子结构。这种预测复杂性的缺乏减缓了开发，并有可能错过当前模型校准之外的新解决方案。 虽然目前的原子模型是有价值的完美晶体的结构-性能关系，没有一个是很好地适合合金偏析原子的长度尺度和扩散的时间尺度必须解决多组分化学。*** 该提案旨在通过部署一种新的模型来填补差距，该模型最近由我们的小组开创，特别是用于预测合金界面和缺陷的偏析。 将该模型与实验程序相结合，我们将绘制出合金元素在界面处的偏析强化潜力，并揭示控制界面相变和形态不稳定性的基本过程。 最终目标是部署这一战略，以彻底改变下一代高强度，轻质结构合金与表面驱动的功能，使用从根本上指导界面结构-性能关系开发作为本提案的一部分。