基于低温化学气相沉积法的碳化硅纤维表面氮化硼涂层制备及表征  

Preparation and characterization of boron nitride coating on silicon carbide fibers based on low-temperature chemical vapor deposition

作　　者：王驰[1] 孙妮娟[1] 张娟[1] 张大海[1] 

机构地区：[1]航天材料及工艺研究所,先进功能复合材料技术国防科技重点实验室,北京100076

出　　处：《科学通报》2016年第22期2536-2542,共7页Chinese Science Bulletin

基　　金：国家高技术研究发展计划(2014AA7024034)资助

摘　　要：以硼氨烷络合物为前驱体,采用低温化学气相沉积（CVD）工艺,在碳化硅纤维表面制备了氮化硼（BN）涂层.采用扫描电子显微镜（SEM）、俄歇电子能谱（AES）、傅里叶变换红外光谱（FTIR）和掠入射X射线衍射（GIAXRD）对涂层进行了表征,采用单纤维电子强力仪测试了碳化硅纤维沉积BN涂层前后的拉伸强度.结果表明BN涂层无孔洞裂纹等缺陷,且表面均一致密,B,N元素比例接近为1：1,纤维与涂层之间相互渗透,结合良好.在较低的沉积温度下可以得到成分单一的BN涂层,涂层微观结构随温度升高更加理想.综合考虑结晶性与纤维强度保留率的情况下,800~1000℃可作为碳化硅纤维BN涂层的最佳沉积温度.在沉积温度为900℃时,随涂层厚度的增加至0.28,0.51和0.82？m,纤维强度保留率分别为92.7%,83.6%,77.7%.Boron nitride （BN） has been considered as promising material owing to its unique properties, such as high thermal stability, high chemical stability, high thermal conductivity and thermal shock resistance. Chemical vapor deposition （CVD） is the most popular method for the preparation of BN. However, the side-products （like HF, HC1 and HBr） are corrosive and the crystallinity of BN is poor if the deposition temperature is 1300℃. Herein we reported a new method for preparing BN by low-temperature CVD using ammonia borane as precursor on silicon carbide fibers. Ammonia borane was sublimated at 110-130℃ using a heating belt, and the sublimated gaseous substance was transported to the deposition region where the silicon carbide fibers were placed at the deposition temperature of 900℃. During the sublimation, a certain quality of ammonia borane was uniformly distributed in the quartz boat with a certain length, and the heating belt moved along the quartz tube with a fixed speed to the end of the boat. Thus the sublimation gas substances could be supplied continually and steadily. Scanning electronic microscopy （SEM）, auger electron spectroscopy （AES）, Fourier translation infrared spectroscopy （FTIR）, and grazing incidence angle X-ray diffraction （GIAXRD） were used to characterize the properties of the coatings, and single fiber electron tensile machine was used to test the tensile strength of silicon carbide fibers without and with different thickness of coatings. The results illustrated that BN coating enwrapped well with the fibers with no defects like voids or cleavages. Meanwhile, the surface of the coating was uniform and dense. And the ratio of B and N was approximate 1： 1. Pure BN coating could be acquired at a relatively low deposition temperature, and microstructure of the BN coating was more ideal with the increasing of deposition temperature. Considering the balance between the coating crystallinity and strength retention of the fiber, 800-1000℃ was the optimum depositio

关 键 词：硼氨烷络合物 化学气相沉积 碳化硅纤维 BN涂层 

分 类 号：TQ343.6[化学工程—化纤工业]