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Development of High Performance Functional Materials by Controlling Grain Boundary Character Distribution and Grain Boundary Geometrical Configuration

通过控制晶界特征分布和晶界几何构型开发高性能功能材料

基本信息

批准号：
13555180
负责人：
WATANABE Tadao
金额：
$ 3.26万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

项目摘要

The concept of "grain boundary design and control for development of high performance polycrystalline materials", which was first proposed by the present author and was recently called "Grain Boundary Engineering", has been extensively accepted as a powerful tool for achieving enhanced properties of structural materials. The aim of this project was therefore to apply the grain boundary engineering to develop high performance functional materials. The chief results obtained were as follows:(1) Effect of Magnetic Field on Grain Growth in Nanocrystalline Nickel : It has been found that a magnetic field can produce a uniform grain structure by suppressing abnormal grain growth in nanocrystalline nickel. In addition, the thermal stability of magnetically annealed sample with uniform grain structure was found to be superior to ordinarily annealed one because further grain growth rarely observed after development of a uniform grain structure by application of the magnetic field.(2)Effect of G … More rain Boundary Character/Structure on Electrical Properties of Polycrystalline Silicon : The electron beam induce current (EBIC) technique and Kelvin probe microscopy (KFM) were applied to study electrical properties of individual grain boundaries in polycrystalline silicon whose character was determined by OIM. It was found that electrical activity of grain boundaries decreased with increasing effective interplanar spacing. KFM measurements revealed that the height of potential barrier was twice higher at random boundaries than at special boundaries.(3)Effect of Grain Boundary Geometrical Configuration on Bulk Electrical Property of Polycrystalline Silicon : We introduced a new microstructural parameters "directional grain size (directional grain boundary density) and directional grain boundary character distribution" to quantitatively evaluate grain boundary microstructures with different grain boundary geometrical configuration. We found that the electrical conductivity of polycrystalline silicon decreased with increasing directional grain boundary density and directional grain boundary character distribution.(4)Control of Grain Boundary Microstructure in Iron Based Alloy by Magnetic Crystallization of Amorphous : Magnetic crystallization of amorphous iron based alloy (Fe_<78>Si_9B_<13>) was carried out to more precisely control gain boundary microstructure. It was found that a sharp {110} texture could be introduced by magnetic crystallization, which resulted in enhanced soft-magnetic properties. Less

“高性能多晶材料开发中的晶界设计与控制”这一概念最早由作者提出，最近被称为“晶界工程”，它已被广泛接受为实现结构材料性能增强的有力工具。因此，本项目的目的是应用晶界工程来开发高性能的功能材料。得到的主要结果如下：(1)磁场对纳米晶镍晶粒生长的影响：研究发现，磁场可以抑制纳米晶镍中的异常晶粒长大，从而产生均匀的晶粒结构。此外，由于在磁场作用下形成均匀的晶粒结构后，很少观察到进一步的晶粒长大，所以磁退火态样品的热稳定性优于常规退火态。(2)G-…效应多晶硅晶界特征/结构对多晶硅电学性质的影响：利用电子束感应电流(EBIC)技术和开尔文探针显微镜(KFM)研究了多晶硅中单晶界的电学性质，其特征是由OIM决定的。结果表明，随着有效晶面间距的增加，晶界的电活性降低。KFM测量表明，随机晶界的势垒高度是特殊晶界的两倍。(3)晶界几何构型对多晶硅电学性能的影响：我们引入了一个新的微观结构参数“定向晶界尺寸(定向晶界密度)和定向晶界特征分布”来定量评价不同晶界几何构型的晶界微结构。研究发现，多晶硅的电导率随着晶界密度和晶界特征分布的增加而降低。(4)非晶态磁晶化对铁基合金晶界组织的控制：对非晶态铁基合金(Fe_&lt；78&gt；Si_9B_&lt；13&gt；)进行了磁晶化处理，以更精确地控制增益界组织。结果表明，磁晶化可以引入尖锐的{110}织构，从而提高了软磁性能。较少