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Development of the evaluation Method for High Temperature Strength of Silicon Nitride

氮化硅高温强度评价方法的研制

基本信息

批准号：
61460084
负责人：
TANAKA Tsuneshichi
金额：
$ 3.14万
依托单位：
Faculty of Sxience and Engineering
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

项目摘要

The purpose of this study was to establish appropriate and precise methods to evaluate the strength and the toughness of silicon nitride ceramics at room and high temperatures. The study was performed in two years from 1986 to 1987, in the Faculty of Science and Engineering, Ritsumeikan University.In 1986, testing equipments to evaluate the strength under monotonic tensile and three points bending load conditions were designed and fablicated. An attension was paid to obtain a precise allignment of the load transmission path in each case. Systematic experiments were conducted at room and high temperatures up to 1300 C on a number of silicon nitride ceramic specimens y using the developed loading equipments. Results obtained through the tests were analized statistically, and the following two points were mainly discussed; (1)temperature dependence of Weibull parameters, and (2) statistical propertirs of the strength under monotonic tensile and three points bending load conditions.In 1987, the experiments were carried out continuing to the previous year, and the results obtained in two years were summarized and discussed to establish the methods of how to evaluate the strength and the toughness of silicon nitride ceramics at room and high temperatures. The obtained results in addition to the above are as follows: (3) The strengthes under two types of load conditions can be well correlated when the effective volume concept is taken into account, (4) the fracture toughness at high temperature takes the same value as that at room temperature when a crack length increment due to slow crack growth is considered at high temperature, and (5) the liner fracture mechanics concept seems to be applicable to the fracture criterion even for small size inherent defects existing in silicon nitride, when the size of segregated Fe area around the fraxture origin is considered as the defect size.

本研究的目的是建立合适的和精确的方法来评估氮化硅陶瓷在室温和高温下的强度和韧性。本研究于1986年至1987年在立命馆大学理工学部进行，历时两年，于1986年设计并制造了在单调拉伸和三点弯曲载荷条件下评估强度的试验设备。注意在每种情况下获得载荷传递路径的精确对准。利用所研制的加载装置，在室温和1300 ℃以下的高温条件下，对大量氮化硅陶瓷试样进行了系统的加载试验。对试验结果进行了统计分析，主要讨论了以下两点：（1）Weibull参数的温度依赖性;（2）单调拉伸和三点弯曲载荷下强度的统计特性。并对两年来的研究结果进行了总结和讨论，建立了氮化硅陶瓷室温和高温强度和韧性的评价方法。除上述结果外，获得的结果如下：（3）当考虑有效体积概念时，两种载荷条件下的强度可以很好地关联;（4）当考虑高温下由于裂纹缓慢扩展而导致的裂纹长度增量时，高温下的断裂韧性与室温下的断裂韧性取相同的值，（5）以裂纹源附近偏聚Fe区的尺寸作为缺陷尺寸时，线性断裂力学概念似乎适用于氮化硅中存在的小尺寸固有缺陷的断裂判据。