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【学术报告】研究生灵犀学术殿堂第227期之陈江华报告会通知
2017-10-13 09:39   研工部 审核人:   (点击: )

1.报告会简介

报告人:陈江华教授/长江学者

时间:2017年10月13日(星期五) 下午15:00(开始时间)

地点: 友谊校区公字楼334

主题: Atomic-resolution electron microscopy for aluminum alloys as high-performance industry materials

内容简介: Developments of high-strength aluminum alloys have always faced a difficult problem: owing to their small size, the early-stage strengthening precipitates are difficult to characterize in terms of composition, structure and evolution. Here we employ atomic-resolution transmission electron microscopy (TEM) imaging and first-principles energy calculations to address these problems. Recent years, we have investigated tens of typical high strength aluminum alloys, such as 2xxx (AlCu, AlCuMg and AlCuLiMg), 6xxx (AlMgSi and AlMgSiCu) and 7xxx (AlZnMg and AlZnMgCu) alloys, with different compositions and with varying thermal processes for understanding their property-structure-process correlations. Using aberration-corrected high-resolution TEM (HRTEM) and aberration-corrected scanning TEM (STEM), much of our attention has been paid to revisit the strengthening precipitates in these important alloys and to clarify the controversies left in the past about their precipitation behaviors. Our study demonstrates the followings:

(1) Atomic-resolution imaging in STEM can provide straightforward structure models at the atomic-scale, whereas atomic-resolution imaging in HRTEM with rapid quantitative image simulation analysis can provide the refined structures with high precision beyond the resolution limitation of the microscope. The combination of the two techniques can be more powerful in solving difficult structure problems in materials science.

(2) Most of the early-stage precipitates in aluminum alloys are highly dynamic in both composition and structure. Typically, having their characteristic genetic skeletons to guide their evolution, these dynamic precipitates initiate, mature and grow with thermal aging following characteristic evolution paths. The fine precipitation scenarios revealed in our studies are rather different from previous understandings in the textbooks and literatures published thus far.

 

报告人简介

陈江华,湖南大学材料科学与工程学院,教授/长江学者。1983年毕业于中南大学金属物理专业,1986年在中科院金属研究所获硕士学位,1997年在比利时安特卫普大学电子显微镜实验室获博士学位。现任湖南大学材料科学与工程学院院长,教授,长江学者。

陈江华在材料科学研究上取得了较突出成果。在系列铝合金微观结构研究方面的成果发表在Science, Acta Materialia, Scripta Materialia等著名杂志;在电子显微学理论与方法研究方面取得多项进展,成果发表于Nature materials, Ultramicroscopy, Micron等专业杂志;在铝合金热处理工艺研发方面形成了国内核心专利。发表论文100余篇,SCI引用3000余次。

回国后,陈江华在湖南大学建成了国际先进、有特色的原子成像技术平台。在普通场发射透射电镜的基础上,成功实现出射波函数重构(EWR)原子成像技术和高角环形暗场扫描透射电镜(HAADF-STEM)原子成像技术,成为世界上能够真正掌握软件校正物镜像差的原子成像技术的三个实验室之一。建成了卓有成效的研究团队,在科研和人才培养上取得了有国际影响的成果。承担了科技部973课题、国家自科基金重大科研仪器研究项目、国防基础研究课题、高铁材料重大横向课题等3000余万元的科研任务。现担任中国材料研究学会常务理事,中国电镜学会常务理事,中国仪表功能材料学会副理事长,湖南省精密仪器测试学会副理事长,若干国内外学术杂志编委。

 

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