Strength Characteristics and Fracture Mechanism of Advanced Continuous Ceramic-Fiber Reinforced Ceramic-Composite

先进连续陶瓷纤维增强陶瓷复合材料的强度特性及断裂机理

• 批准号: 04650064
• 负责人: HOSHIDE Toshihiko
• 金额: $ 1.28万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04650064/
• 关键词: Engineering ceramics; Continuous ceramic fiber; Fiber reinforced composite; Fracture mechanism; Fracture mechanics; Strength Characteristics; Statistical behavior; Interface structure; セラミックス長繊維

Strength characteristics and frature mechanim of a silicon carbide matrix reinforced by continuous silicon carbide fiber were investigated. In the material, satin woven cloths with carbon-coated fiber were impregnated in matrix binder, followed by repeated process of molding, cure and burning. Specimens subjected to loading vertically to stacking layrs and those pallarel to stacking layrs were designated as V-specimen and P-specimen, respectively. Unstable fracture was not observed for both types of specimen, because of interface property refined by carbon coating on fiber. Apparent fracture toughness and bending strength in P-specimen were found to be larger than those in V-specimen. This was resulted from difference in the fracture morphology depending on stacking direction. In V-specimen, pull-out and tensile rapture of fibers were dominant in fracture process, and resulted in separation into two parts. On the other hand, in P-specimen, separation in interlaminate was obserbed before final frature. The differnce in macroscopic fracture pattern was supposed to appear in the fracture resistance. The reinforcement effect by fiber in the present material was investigated by ccmlparison with strength characteristics of the matrix material. In this case, the strength characteristics of the matrix material were estimated by taking account of its bulk density. By the comparison, apparent fracture toughness and bending strength of each type of specimen were found to be larger than those estimated for the matrix. The effect of fiber reinforcement was concluded to be affirmed as long as strength of the bulk material was compared with that of matrix strength.

研究了连续碳化硅纤维增强碳化硅基体的强度特性和断裂机理。在该材料中，将具有碳涂层纤维的缎纹编织布浸渍在基质粘合剂中，然后重复成型、固化和燃烧过程。垂直于堆垛层加载的试样和垂直于堆垛层加载的试样分别称为V型试样和P型试样。两种试样均未观察到不稳定断裂，这是由于纤维表面碳涂层改善了界面性能。P型试样的表观断裂韧性和抗弯强度均大于V型试样。这是由于取决于堆叠方向的断裂形态的差异。在V型试样中，纤维的拔出和拉伸断裂占主导地位，并导致了两部分的分离。而P型试样在最终断裂前，层间的分离已被消除。宏观断裂形态的差异可能表现在断裂抗力上。结合基体材料的强度特性，研究了纤维在本材料中的增强作用。在这种情况下，通过考虑其体积密度来估计基质材料的强度特性。通过比较，发现每种类型试样的表观断裂韧性和弯曲强度均大于基体的估计值。通过对块体材料强度与基体强度的对比，可以肯定纤维增强的效果。