热解气氛对氮化硼纤维相转变-力学性能的影响研究  

Influence of Pyrolysis Atmosphere on Phase Transformation and Mechanical Properties of Boron Nitride Fibers

作　　者：齐学礼 丁伟宸[2] 程之强 姚建尧 QI Xueli;DING Weichen;CHENG Zhiqiang;YAO Jianyao(College of Aerospace Engineering,Chongqing University,Chongqing 400044,China;Shandong Industrial Ceramic Research&Design institute Co.,Ltd.,Zibo 255000,China)

机构地区：[1]重庆大学航空航天学院,重庆400044 [2]山东工业陶瓷研究设计院有限公司,淄博255000

出　　处：《硅酸盐通报》2025年第3期1110-1122,共13页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金(U2241241)。

摘　　要：氮化硼(BN)纤维是制备超高温陶瓷基透波复合材料的重要增强体,是高马赫数飞行器透波天线罩发展和应用的关键材料。因此深入研究BN纤维微观结构和力学性能的关系对新一代装备的发展显得尤为重要。本研究采用熔融纺丝法制备BN前驱体纤维,并进一步对纤维无机化及陶瓷化热处理过程中的结构及性能进行了系统表征。BN前驱体纤维经过无机化转变成无机非晶BN中间体纤维,再经过高温烧结变成微晶BN纤维,最终形成只有B—N—B结构的六元环。研究探讨了N_(2)和NH_(3)气氛下热处理过程中纤维的微观形貌、结构转变、结晶性及力学性能的变化规律。结果表明,采用NH_(3)作为反应气氛时,所得BN中间体纤维结构致密,具有一定晶格条纹的BN微晶粒(t-BN),碳含量仅为0.09%(质量分数),经过陶瓷化后的BN-10NH-16纤维拉伸强度和弹性模量分别达到了832.14 MPa和74.88 GPa。采用N_(2)作为反应气氛时,所得BN中间体纤维截面出现明显的孔洞缺陷,但无微晶粒生成,碳含量为18.00%(质量分数),经过陶瓷化后的BN-10N-16纤维拉伸强度和弹性模量分别达到了383.98 MPa和71.73 GPa。XRD和HRTEM测试结果表明,1600℃、NH_(3)气氛下无机化的BN-10NH-16纤维结晶度大幅提高,并沿着纤维的轴向存在一定的取向度,纤维的力学性能显著提升。同时,通过威布尔分布拟合,验证了纤维微结构缺陷与力学性能之间的关系,这为后续高性能BN纤维的制备提供了重要的参考依据。Boron nitride(BN)fiber is an important reinforcement for the preparation of ultra-high temperature ceramicbased wave-transparent composites,and it is a key material for the development and application of high Mach number aircraft wave-transparent radomes.Therefore,through investigation into the relationship between the microstructure and mechanical properties of BN fibers is particularly important for the progress of new-generation equipment.In this study,BN precursor fibers were prepared using the melt spinning method,and the structure and properties of BN fibers during the inorganic and ceramicization heat treatment were systematically characterized.The BN precursor fibers were converted into inorganic amorphous BN intermediate fibers,which were subsequently sintered at high temperatures to yield microcrystalline BN fibers,ultimately forming a structure composed exclusively of B—N—B hexagons.The study investigated the alterations in microstructure,structural transformation,crystallinity,and mechanical properties of the fibers during heat treatment under N_(2)and NH_(3)atmospheres.The results indicat that when NH_(3)is employed as the reaction atmosphere,the intermediate fibers have a dense structure,containing BN microcrystals(t-BN)with distinct lattice fringes,and the carbon content is only 0.09%(mass fraction).The tensile strength and elastic modulus of BN-10NH-16 fibers ceramicization reaches 832.14 MPa and 74.88 GPa,respectively.When N_(2)is employed as the reaction atmosphere,the cross-section of the BN intermediate fibers exhibit obvious pores and defects,but no microcrystals are formed,and the carbon content remaines at 18.00%(mass fraction).The tensile strength and elastic modulus of the BN-10N-16 fibers after ceramicization reaches 383.98 MPa and 71.73 GPa,respectively.XRD and HRTEM results indicate that the crystallinity of inorganic BN-10NH-16 fibers are significantly improved at 1600℃under NH_(3)atmosphere,and there is a certain degree of orientation along the axis direction of fibers,which th

关 键 词：氮化硼纤维 熔融纺丝法 结构转变 微缺陷 结晶性 

分 类 号：TQ174[化学工程—陶瓷工业]