Properties of Consolidated Nanocrystalline Metals and Composites

固结纳米晶金属和复合材料的性能

• 批准号: 9877006
• 负责人: En (Evan) Ma
• 金额: $ 18万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9877006&HistoricalAwards=false
• 关键词: Properties; Consolidated; Nanocrystalline; Metals; Composites

The main objective of this research is to understand the inherent mechanical properties of full-density nanocrystalline metallic alloys. Continuing on with our recent progress in devloping procedures to consolidate mechanicallu milled nanophase metal and alloy powders into full-density samples, this work expands the investigation on basic properties to a number of elemental and two phase materials. To systematically investigate the intrinsic mechanical response, nanophase and ultrafine-grained metals and alloys will be prepared with special care taken to minimize porosity and particle debonding problems. Testing will be conducted in compression and tension. Fundamental deformation behavior and mechanisms will be studies. In particular, dislocation structure and behavior in single-and two-phase alloys, before and after deformation, inside grains and near interfaces (grain vs. phase boundaries), will be characterized and monitored over a range of grain sizes. The strain hardening and shear banding behavior and their dependence on composition and grain size will be investigated and compared with those found in conventional materials. The strengthening effects of interphase boundaries in multi-phase alloys will be characterized and modeled. Nanocrystalline metals and multi-phase alloys with a useful combination of mechanical properties will be demonstrated.***

这项研究的主要目的是了解全密度纳米晶金属合金的固有机械性能。继续我们在Devloping程序方面的最新进展，以将Mechanicallu铣削的纳米相金属和合金粉末合并为全密度样品，这项工作将对基本特性的研究扩展到了许多元素和两种相材料。为了系统地研究固有的机械响应，将通过特殊谨慎地制定纳米相和超铁粒金属和合金，以最大程度地减少孔隙率和颗粒脱根本问题。测试将以压缩和张力进行。基本变形行为和机制将是研究。特别是，将在一系列晶粒尺寸的范围内对单一和两相合金的位错结构和行为（晶粒内部和近界面（晶粒与相边界））进行表征和监测。应对应变硬化和剪切带的行为及其对组成和晶粒尺寸的依赖，并将其与常规材料中的菌株进行比较。在多相合金中，相间边界的加强作用将被表征和建模。将展示具有机械性能组合的纳米晶金属和多相合金。***