CAJ | 학술논문

利用三维编织炭纤维预制件通过先驱体浸渍裂解法制备C/SiC复合材料.研究了热解碳(PyC)/SiC界面相对复合材料的微观结构和力学性能的影响.弯曲性能通过三点弯曲法测试,复合材料的断口和抛光面通过扫描电镜观察.结果表明:通过等温化学气相沉积法在纤维表面沉积PyC/SiC界面相以后,复合材料的三点抗弯强度从46 MPa提高到247 MPa.沉积界面的复合材料断口有明显的纤维拔出现象,纤维与基体之间的结合强度适当,起到了增韧作用;而未沉积界面相复合材料的断口光滑、平整,几乎没有纤维拔出,纤维在热解过程中受到严重的化学损伤,性能下降严重,材料表现为典型的脆性断裂.
이용삼유편직탄섬유예제건통과선구체침지렬해법제비C/SiC복합재료.연구료열해탄(PyC)/SiC계면상대복합재료적미관결구화역학성능적영향.만곡성능통과삼점만곡법측시,복합재료적단구화포광면통과소묘전경관찰.결과표명:통과등온화학기상침적법재섬유표면침적PyC/SiC계면상이후,복합재료적삼점항만강도종46 MPa제고도247 MPa.침적계면적복합재료단구유명현적섬유발출현상,섬유여기체지간적결합강도괄당,기도료증인작용;이미침적계면상복합재료적단구광활、평정,궤호몰유섬유발출,섬유재열해과정중수도엄중적화학손상,성능하강엄중,재료표현위전형적취성단렬.
3D braided carbon fiber preforms were used to fabricate C/SiC composites using polymer infiltration and pyrolysis (PIP). Before the PIP, the preforms were coated by isothermal chemical vapor infiltration with methane to produce pyrocarbon (PyC) and then with hexamethyldisilazane to form SiC and produce the PyC/SiC interphase. The correlation of the PyC/SiC interphase to the microstructure and the mechanical properties of the fabricated composites was investigated. The flexural properties of the composites were measured using the three-point-bend test, and the fracture surfaces observed by SEM. The bend strengths were 247 MPa and 46 MPa, with and without the PyC/SiC interphase respectively. Long fiber pullout dominated the fracture surface for the composite with the PyC/SiC interphase, while for the one without the interphase, almost no fiber pullout was observed.