高温氧化环境下BN/SiC涂层的氧化行为及SiC纤维的性能研究  

Oxidation Behavior of BN/SiC Coatings and Properties of SiC Fibers at High-Temperature

作　　者：赵文青 齐哲 吕晓旭 杨瑞 焦健 ZHAO Wenqing;QI Zhe;LÜXiaoxu;YANG Rui;JIAO Jian(Surface Engineering Institution,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;National Key Laboratory of Advanced Composites,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China)

机构地区：[1]中国航发北京航空材料研究院表面工程研究所,北京100095 [2]中国航发北京航空材料研究院先进复合材料国防科技重点试验室,北京100095

出　　处：《航空制造技术》2024年第20期90-96,117,共8页Aeronautical Manufacturing Technology

摘　　要：利用化学气相渗透(CVI)工艺在SiC纤维表面沉积BN/SiC涂层,并进一步通过表征技术探究含有涂层纤维在高温氧化环境下表面涂层和纤维的理化性能。附着涂层纤维被放置于1050~1200℃的空气环境氧化0.5~2 h,利用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、纳米扫描俄歇仪(AES)和X射线光电子能谱仪(XPS)对氧化后的BN/SiC涂层形貌、结构以及成分进行了表征,最后利用单丝拉伸强度评价了附着BN/SiC涂层的SiC纤维氧化后的力学性能。试验结果表明,BN/SiC涂层在高温氧化后,表面出现气孔、鼓泡、裂纹和氧化物析出等现象,并且BN/SiC涂层未被完全氧化,仍具备保护内部SiC纤维的能力。通过对试验数据进一步分析发现,附着涂层的纤维在1200℃和1350℃氧化后主要失效机理有所差异,前者为涂层和纤维之间形成的缝隙及气孔,而后者为产生的氧化物及其裂纹。BN/SiC coatings were deposited on the surface of SiC fibers by chemical vapor infiltration(CVI)process,and the physicochemical properties of the surface coatings and the fibers were further investigated by characterization techniques in a high-temperature oxidation environment.The fibers coated with BN/SiC coatings were treated at 1050–1200℃for 0.5–2 h in air environment.The morphology,structure and composition of the oxidized BN/SiC coatings were characterized by scanning electron microscopy(SEM),X-ray diffractometer(XRD),nano-scanning Auger(AES)and X-ray photoelectron spectroscopy(XPS).The mechanical properties of SiC fibers coated with BN/SiC coatings after oxidation were evaluated by tensile strength of monofilament.The results show that the BN/SiC coatings are not completely oxidized and still have the ability to protect the internal SiC fibers.Through further analysis of the experimental data,it is found that the main failure mechanisms of the fibers attached to the coatings after oxidation at 1200℃and 1350℃are different,with the former being the formation of gaps and pores between the coatings and fibers,and the latter being the production of oxides and their cracks.

关 键 词：SIC纤维 BN/SiC涂层 高温 氧化产物 单丝强度 

分 类 号：TB306[一般工业技术—材料科学与工程] TQ343.6[化学工程—化纤工业]