Fabrication of dense SiBCN monolith at a lower temperature and its high-temperature performance  

作　　者：Zi-Bo Niu Daxin Li Dechang Jia Zhihua Yang Kunpeng Lin Yan Wang Paolo Colombo Ralf Riedel Yu Zhou 

机构地区：[1]Institute for Advanced Ceramics,School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150080,China [2]Key Laboratory of Advanced Structural-Function Integrated Materials and Green Manufacturing Technology,Ministry of Industry and Information Technology,Harbin 150080,China [3]State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin 150080,China [4]Department of Industrial Engineering,University of Padova,Padova 3513i,Italy [5]Department of Materials Science and Engineering,The Pennsylvania State University,University Park 16802,USA [6]Institute of Materials Science,Darmstadt University of Technology,Darmstadt 64287,Germany [7]School of Materials Science and Engineering,Harbin Institute of Technology(Shenzhen),Shenzhen 518055,China

出　　处：《Journal of Advanced Ceramics》2024年第8期1198-1211,共14页先进陶瓷（英文）

基　　金：This work was financially supported by the National Natural Science Foundation of China(Nos.52372059,52172068,52232004,and 52002092);the Heilong Jiang Natural Science Fund for Young Scholars(No.YQ2021E017);the Fundamental Research Funds for the Central Universities(No.2022FRFK060012);the Heilongjiang Touyan Team Program,and the Advanced Talents Scientific Research Foundation of Shenzhen:Yu Zhou;This work was also funded by the Beijing Engineering Research Center of Efficient and Green Aerospace PropulsionTechnology and Advanced Space Propulsion Laboratory of Beijing Institute of Control Engineering(BICE)(No.LabASP-2023-11).

摘　　要：In this study,a crack-free pyrolysis process of partially cured precursor powder compacts was developed to prepare dense silicon boron carbonitride(SiBCN)monoliths at much lower temperatures(1300℃),thereby circumventing the challenges of sintering densification(>1800℃).Unlike the elastic fracture in over-cured precursors or the viscoelastic deformation in under-cured precursors,the partially cured precursor,exhibiting elastic-plastic deformation behavior,facilitates limited nanoscale pore formation in a dense structure,achieving a balance between crack-free pyrolysis and densification.Compared to SiBCN derived from the over-cured precursor(σ=~159 MPa,K_(IC)=1.9 MPa:m^(1/2),Vickers hardness(HV)=7.8 GPa,and E=122 GPa),the resulting SiBCN monolith exhibited significantly improved mechanical properties(σ=~304 MPa,K_(IC)=3.7 MPa-m12,HV=10.6 GPa,and E=161 GPa)and oxidation resistance.In addition,this study investigated the high-temperature performance of SiBCN monoliths,including crystallization and oxidation,and determined the oxidation kinetics induced by pore structure healing and the different oxidation mechanisms of Si-C-N and B-C-N clusters in the amorphous structure.Due to its unique composition and structure,the SiBCN ceramic oxide layer exhibits exceptional self-healing effects on repairing the nanoporous system in the initial stage and shows outstanding high-temperature stability during prolonged oxidation,mitigating adverse effects from bubble formation and crystallization.Due to the nanoporous structure,the oxidation rate is initially controlled by gas diffusion following a linear law before transitioning to oxide layer diffusion characterized by a parabolic law.Finally,due to different valence bond configurations,Si-C-N transforms into an amorphous SiCNO structure after phase separation,unlike the nucleation and growth of residual B-N-C.

关 键 词：silicon boron carbonitride(SiBCN)ceramics crack-free pyrolysis amorphous structure oxidation mechanisms kinetic law 

分 类 号：V25[一般工业技术—材料科学与工程] TQ342[航空宇航科学与技术—航空宇航制造工程]