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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受到了特别关注。由于硅单晶在较窄的温度范围内表现出从脆性到延性行为的急剧转变，因此作为模型晶体来了解增韧晶体材料的位错过程而受到广泛关注。在这项研究中，使用高压电子显微镜检查了硅晶体中裂纹尖端位错的性质及其倍增过程。通过将图像与模拟图像进行匹配来表征观察到的裂纹尖端位错，发现它们是屏蔽型的，增加了材料的断裂韧性。除此之外，还在 1100K 左右的高温下进行了三点弯曲测试，以便在裂纹尖端周围引入位错。通过红外光弹性方法对高温变形的硅晶体中的裂纹尖端应力场进行可视化。通过使用该方法，证实了通过引入位错在裂纹尖端周围形成压应力场，并且压应力场显着提高了硅晶体的断裂韧性。进一步，利用MPI Hartmaier博士开发的程序代码对位错分布进行了模拟，计算出的位错分布模拟的光弹图像与观测图像吻合良好。从硅晶体可加工性研究的角度出发，研究了杂质和应变率对脆塑转变行为的影响。在这项研究中，添加了硼，导致脆韧转变温度（BDTT）升高。根据BDTT应变率依赖性的结果，估计了脆塑转变的活化能，并且估计值与位错滑移的活化能值非常吻合。这些结果表明，基于位错运动和裂纹与位错相互作用的理论，从根本上讨论了硅晶体的脆塑转变和可加工性问题。较少的

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