CAJ | 학술논문

本文采用微波水热技术在碳纤维预制体中原位合成ZrO2，经热梯度化学气相渗透致密化和高温石墨化处理，制备了C／C‐ZrC复合材料．利用氧乙炔焰测试C／C‐ZrC复合材料的抗烧蚀性能，研究了ZrC含量对复合材料抗烧蚀性能的影响规律；借助XRD、SEM 等测试手段分析复合材料烧蚀前后的物相及微观结构．研究结果表明：C／C复合材料内的ZrO2经碳热还原反应后转变为亚微米级ZrC颗粒，可弥散分布在基体碳中．当ZrC含量为7．33 w t％时，复合材料呈现出最低的烧蚀率，相比 C／C 复合材料，线烧蚀率和质量烧蚀率分别降低了27．1％和37．9％．当Z rC含量为8．92 w t％时，复合材料中裂纹的增加是烧蚀性能降低的主要原因．裂纹不仅提供了氧扩散通道加速碳的氧化，而且裂纹的增加降低了复合材料的导热系数，使复合材料在烧蚀过程具有较高的表面温度以加速复合材料的烧蚀．
본문채용미파수열기술재탄섬유예제체중원위합성ZrO2，경열제도화학기상삼투치밀화화고온석묵화처리，제비료C／C‐ZrC복합재료．이용양을결염측시C／C‐ZrC복합재료적항소식성능，연구료ZrC함량대복합재료항소식성능적영향규률；차조XRD、SEM 등측시수단분석복합재료소식전후적물상급미관결구．연구결과표명：C／C복합재료내적ZrO2경탄열환원반응후전변위아미미급ZrC과립，가미산분포재기체탄중．당ZrC함량위7．33 w t％시，복합재료정현출최저적소식솔，상비 C／C 복합재료，선소식솔화질량소식솔분별강저료27．1％화37．9％．당Z rC함량위8．92 w t％시，복합재료중렬문적증가시소식성능강저적주요원인．렬문불부제공료양확산통도가속탄적양화，이차렬문적증가강저료복합재료적도열계수，사복합재료재소식과정구유교고적표면온도이가속복합재료적소식．
The C/C‐ZrC composites were prepared by the following process .First ,zirconia was introduced into the carbon fiber preforms by a microwave‐hydrothermal reaction .And then , the C/C‐ZrC composites were desified by thermal gradient chemical vapor infiltration .The ablation property of the composites was performed with an oxyacetylene torch .The effect of the addition of ZrC on the ablation resistance of the composites was studied .The phase and microstructure of the composites were analyzed by XRD and SEM .Results show that the ZrO2 in the composites was fully converted into submicrometer ZrC by a carbothermal reduc‐tion reaction of ZrO2 with pyrocarbon .The ZrC grain is uniformly embedded in the carbon matrix .The C/C composites containing 7 .33 wt% ZrC exhibit the best ablation resistance . Compared with the C/C composites ,the linear and mass ablation rate was reduced by 27 .1%and 27 .1% respectively .The decrease in the ablation resistance of the composites is attribu‐ted to the increasing number of cracks in the composites ,when the ZrC content is 8 .92 wt% .Oxidation is accelerated by the cracks in the composites as they enable the oxidizing agent to diffuse .Furthermore ,cracks can reduce the thermal conductivity of the composites ,which re‐sults in an increase in ablation temperature and acceleration of ablation .