不同热解碳界面层厚度C/ZrC-SiC复合材料烧蚀性能及其机理  

Ablation Properties and Mechanisms of C/ZrC-SiC Composites with Pyrolytic Carbon Interlayer of Different Thickness

作　　者：杨晓辉 李克智[1] 白龙腾 郭亚威 YANG Xiaohui;LI Kezhi;BAI Longteng;GUO Yawei(School of Materials Science and Engineering,Northwestern Polytechnical University,Xi'an 710072,China;Xi’an Aerospace Propulsion Institute,Xi'an 710010,China)

机构地区：[1]西北工业大学材料学院,西安710072 [2]西安航天动力研究所,西安710010

出　　处：《材料研究学报》2022年第7期489-499,共11页Chinese Journal of Materials Research

基　　金：国家自然科学基金(U51521061,51772247)。

摘　　要：通过控制沉积时间制备S5-C/ZrC-SiC、S15-C/ZrC-SiC、S30-C/ZrC-SiC和S50-C/ZrC-SiC等不同热解碳界面层厚度的复合材料,研究了不同热解碳界面层厚度C/ZrC-SiC复合材料的密度与微观组织、烧蚀性能的变化规律及其机理。结果表明:随着热解碳界面层厚度的增大,C/ZrC-SiC复合材料SiC基体含量、密度和气孔率不断降低,但是裂解ZrC基体的含量表现出先降低而后增大的变化规律。S30-C/ZrC-SiC复合材料20 s短时间氧乙炔烧蚀性能最优,其质量烧蚀率和线烧蚀率分别-0.84 mg/s和3.00μm/s;但是S15-C/ZrC-SiC复合材料长时间循环60 s烧蚀性能最优,其质量烧蚀率和线烧蚀率分别为1.22 mg/s和3.80μm/s。其原因是,C/ZrC-SiC复合材料20 s氧乙炔烧蚀作用机理主要为机械冲刷,而C/ZrC-SiC复合材料的第二次60 s氧乙炔烧蚀发生了由机械冲刷向热物理和热化学烧蚀机理的转变。Composites of C/ZrC-SiC with pyrolytic carbon(PyC) interlayers of different thickness,namely, S5-C/ZrC-SiC, S15-C/ZrC-SiC, S30-C/ZrC-SiC, and S50-C/ZrC-SiC were prepared by adjusting the deposition time. The variation of density, microstructure and ablation properties of C/ZrC-SiC composites with interlayer PyC of different thickness was systematically studied. The results show that with the increasing thickness of interlayer PyC, the density and porosity of C/ZrC-SiC composites decrease, but the content of the pioneer impregnation pyrolysis ZrC matrix decreases first and then increases. As for 20 s short time oxyacetylene ablation, S30-C/ZrC-SiC composites presents the best ablation performance,and its mass ablation rates and linear ablation rates are-0.84 mg/s and 3.00 μm/s, respectively;while for 60 s long time cycle ablation test, S15-C/ZrC-SiC composites has the best ablation performance, and its mass ablation rates and linear ablation rates are 1.22 mg/s and 3.80 μm/s, respectively. The mechanism for the 20 s oxyacetylene ablation of C/ZrC-SiC composites may be ascribed to mechanical erosion,while for the second 60 s oxyacetylene ablation of C/ZrC-SiC composites, the ablation mechanism may be described as that the ablation process changes from mechanical erosion to thermo-physical and thermo-chemical ablation.

关 键 词：复合材料 热解碳界面层 烧蚀性能 烧蚀机理 

分 类 号：TB322[一般工业技术—材料科学与工程]