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A Study on Method for Evaluating Fracture Strength of Brittle Thin Films Using a Small Spherical Indentation

小球形压痕评价脆性薄膜断裂强度方法的研究

基本信息

批准号：
05452123
负责人：
TAKAMATSU Tohru
金额：
$ 4.67万
依托单位：
The University of Electro-Communications
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05452123/
关键词：
Thin Film Small Spherical Indenter Indentation Fracture Strength

项目摘要

The aim of this research is to study the method for evaluating fracture Stregth of brittle thin films using a small spherical indentation. The principal results of the research are summarized as follows.1. An attempt was made to evaluate Young's E and fracture strength sigma_f of a thin film of permaloy and SiO_2 with a thickness of 2mum using cross-shaped micro-specimens. It was found that E and sigma_f could be evaluated nearly using the proposed method.2. The microfracture strength of TiN film or Al_2O_3 film with a thickness of 2mum coated on a WC substrate was evaluated by indenting a spherical indenter. It was found that as spherical indenter was smaller, the ring crack initiation strength was large. An attempt was made to estimate the bending fracture strength of the bulk materials from the ring crack initiation strength using the concept of effective area. A reasonable value was obtained for the bending fracture strength.3. Before evaluation of fracture strength of a thin film … More coated on a substrate by indenting a spherical indenter, indentation tests on Si_3N_4 bulk plates using a Si_3N_4 spherical indenter were carried out. The relationship between the ring crack initiation strength evaluated from indentation tests and bending fracture strength was examined using the concept of effective area. It was found that the ring crack initiation strength was larger than the bending fracture strength and as spherical indenter was smaller, the ring crack initiation strength was larger. It was found that ring crack initiation strength could not be related to conventional bending fracture strength, using the concept of effective area.4. To find the cause that the ring crack initiation strength of Si_3N_4 bulk plates evaluated by the sphere indentation method could not be related to conventional bending fracture strength, using the concept of effective area, a ring crack initiation model of a surface microcrack was applied. It was confirmed that the difference between the ring crack initiation strength and bending fracture strength could be interpreted qualitatively. Less

本研究的目的是研究利用小球面压痕评价脆性薄膜断裂强度的方法。本研究的主要成果总结如下：1.研究成果。用十字形微试样法测定了厚度为2微米的坡莫合金和SiO_2薄膜的杨氏E和断裂强度σ_f。结果表明，E和Sigma_f几乎可以用所提出的方法来计算。用球面压痕的方法研究了WC衬底上2微米厚的TiN薄膜和Al_2O_3薄膜的微断裂强度。结果表明，球形压头越小，环裂纹萌生强度越大。尝试用有效面积的概念从环形裂纹的萌生强度来估算块体材料的弯曲断裂强度。得出了合理的抗弯断裂强度取值。薄膜…断裂强度评估前的研究利用球形压头在衬底上进行了更多的涂层，利用Si3N4球形压头对Si3N4块材进行了压痕试验。利用有效面积的概念，研究了由压痕试验估算的环裂纹萌生强度与弯曲断裂强度之间的关系。结果表明，环裂纹萌生强度大于弯曲断裂强度，且球形压头越小，环裂纹萌生强度越大。利用有效面积的概念，发现环裂纹萌生强度与常规弯曲断裂强度之间不存在相关性。为了找出用球压痕法估算的Si3N4块材的环裂纹萌生强度不能与常规弯曲断裂强度相关联的原因，利用有效面积的概念，应用了表面微裂纹的环裂纹萌生模型。结果表明，可以定性地解释环裂纹萌生强度与弯曲断裂强度之间的差异。较少