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Mesoscopic-scale dynamics of materials fracture and workability of silicon crystals

材料断裂的细观动力学和硅晶体的可加工性

基本信息

批准号：
16360316
负责人：
HIGASHIDA Kenji
金额：
$ 7.04万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

项目摘要

Mesoscopic-scale dynamics of materials fracture have been investigated based on the theory of crack-dislocation interaction. Particular attention has been paid on fracture and deformation behaviors in silicon single crystals.Since silicon single crystals exhibit a sharp transition from brittle-to-ductile behavior in the narrow temperature range, they have attracted much attention as model crystals to understand the dislocation process for toughening crystalline materials. In this research, the nature of crack tip dislocations and their multiplication processes in silicon crystals have been examined by using high-voltage electron microscopy. The crack tip dislocations observed were characterized by matching their images to those simulated, and it was found that they were shielding type which increases fracture toughness of materials. In addition to this, three-point bending tests were made at high temperatures around 1100K in order to introduce dislocations around a crack tip. And crack … More tip stress fields were visualized by infrared photoelastic method in those silicon crystals deformed at high temperatures. By using this method, it was confirmed that the compressive stress field was formed around the crack tip by the introduction of dislocations, and that the compressive stress fields substantially increases the fracture toughness of silicon crystals. Further, the dislocation distribution was simulated by using the program code developed by Dr. Hartmaier, MPI, and the simulated photoelastic images using the calculated dislocation distribution were in good agreement with the observed images.From the viewpoint of the research on the workability of silicon crystals, the effects of impurity and strain rate on the behavior of brittle-to-ductile transition was investigated. In this study, boron was added, which caused the increase of brittle-to-ductile transition temperature (BDTT). Based on the results of strain rate dependence of BDTT, activation energy for brittle-to-ductile transition was estimated, and the value estimated coincided well with the value of the activation energy of dislocation glide. Those results suggest that the problem of brittle-to-ductile transition and workability of silicon crystals are fundamentally discussed based on the theory of dislocation motion and the interaction between crack and dislocations. Less

基于裂纹-位错相互作用理论，研究了材料断裂的细观动力学。硅单晶的断裂和变形行为一直受到人们的关注，由于硅单晶在较窄的温度范围内表现出从脆性到韧性的急剧转变，因此它们作为模型晶体引起了人们对晶体材料增韧位错过程的极大关注。本研究用高压电子显微镜研究了硅单晶中裂纹尖端位错的性质及其扩展过程。将观察到的裂尖位错图像与模拟结果进行了匹配，发现它们是屏蔽型位错，提高了材料的断裂韧性。此外，为了在裂纹尖端周围引入位错，在1100K左右的高温下进行了三点弯曲试验。和Crack…用红外光弹方法观察到高温变形的硅单晶尖端应力场较大。用这种方法证实了位错的引入在裂纹尖端周围形成了压应力场，压应力场显著提高了硅单晶的断裂韧性。在此基础上，利用MPI的Hartmaier博士开发的程序模拟了位错的分布，利用计算的位错分布模拟的光弹图像与观测图像吻合较好。从研究硅晶体的加工性的角度出发，研究了杂质和应变速率对脆韧转变行为的影响。在本研究中，硼的加入导致了脆韧转变温度(BDTT)的提高。根据BDTT应变速率关系的结果，估算了脆韧转变的激活能，其估计值与位错滑移激活能的值吻合较好。这些结果表明，基于位错运动理论和位错与裂纹的相互作用，从根本上讨论了硅晶体的脆韧转变和可加工性问题。较少

项目成果

期刊论文数量（6）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Fracture Toughness Evaluated by Indentation Methods and Its Relation to Surface Energy in Silicon Single Crystals

DOI：
10.2320/matertrans.44.681
发表时间：
2003-04
期刊：
Materials Transactions
影响因子：
1.2
作者：
Masaki Tanaka;K. Higashida;H. Nakashima;H. Takagi;M. Fujiwara
通讯作者：
Masaki Tanaka;K. Higashida;H. Nakashima;H. Takagi;M. Fujiwara

3D Structures of Crack-Tip Dislocations in Silicon Revealed by HVEM

HVEM 显示硅中裂纹尖端位错的 3D 结构

DOI：
发表时间：
2004
期刊：
Proceedings of the 25th Risoe International Symposium on Materials Science : Evolotion of Deformation Microstructures in 3D, Editors : C. Gundlach et. al., Risoe National Laboratory, Roskide, Denmar
影响因子：
0
作者：
K.Higashida;M.Tanaka
通讯作者：
M.Tanaka

Microstructure of plastic zones around crack tips in silicon revealed by HVEM and AFM

DOI：
10.1016/j.msea.2004.05.040
发表时间：
2004-12
期刊：
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
影响因子：
6.4
作者：
Masaki Tanaka;K. Higashida;Tomoko Haraguchi
通讯作者：
Masaki Tanaka;K. Higashida;Tomoko Haraguchi

Crack Tip Stress Fields Revealed by Infrared Photoelasticity in Silicon Crystals

硅晶体中红外光弹性揭示的裂纹尖端应力场