A novel super-hybrid composite (NSHC) is prepared with three-dimension reticulated SiC ceramic (3DRC), high performance carbon fibers and modified phenolic resin (BPR) in this paper. Ablation performance of super-hybr...A novel super-hybrid composite (NSHC) is prepared with three-dimension reticulated SiC ceramic (3DRC), high performance carbon fibers and modified phenolic resin (BPR) in this paper. Ablation performance of super-hybrid composite is studied. The results show that the NSHC has less linear ablation rate compared with pure BPR and CF/BPR composite, for example, its linear ablation rate is 50% of CF/BPR at the same fiber content. Mass ablation rate of the NSHC is slightly lower than that of pure BPR and CF/BPR composite because of their difference in the density. Scanning electron microscopic analysis indicates that 3DRC can increase anti-erosion capacity of materials because its special reticulated structure can control the deformation of materials and strengthen the stability of integral structure.展开更多
Relationship between K2O-Al2O3-SiO2 system dental glass ceramics and Al2O3 ceramics was investigated. 4 groups of glass ceramic with the same components but different thickness（0.8, 1.2, 1.6, and 2.0 mm） were sinter...Relationship between K2O-Al2O3-SiO2 system dental glass ceramics and Al2O3 ceramics was investigated. 4 groups of glass ceramic with the same components but different thickness（0.8, 1.2, 1.6, and 2.0 mm） were sintered on Al2O3 base ceramics according to the same thermal treatment system of leucite micro-crystallization reported in previous literatures. The products of each group were analyzed by polarizing microscope, X-ray diffractometer, and an INSTRON material testing machine. Under the thermal treatment system, leucite crystals were formed in samples of each group, and dispersed evenly. Meanwhile, the compressive strengths of group 3 and group 4 were higher than those of group 1 and group 2. Samples of group 3 showed better mechanical properties than others. The conclusions are drawn that Leucite crystals can be controlled in K2O-Al2O3-SiO2 system glass ceramic-Al2O3 ceramic composite material, and the thickness of glass ceramic has a notable influence on the compressive strength of this ceramic composite material.展开更多
Highly oriented graphite-based composites have attracted great attention because of their high thermal conductivity(TC),but the low mechanical properties caused by the inhomogeneous distribution and discontinuity of r...Highly oriented graphite-based composites have attracted great attention because of their high thermal conductivity(TC),but the low mechanical properties caused by the inhomogeneous distribution and discontinuity of reinforcements restrict the wide applications.Herein,continuous SiC ceramic skeleton reinforced highly oriented graphite flake(SiC/GF)composites were successfully prepared by combining vacuum filtration and spark plasma sintering.The effect of SiC concentration on the microstructure,flexural strength,and thermophysical properties of the composites was investigated.The GF grains in the composites exhibited high orientation with a Lotgering factor of>88%when the SiC concentration was≤30 wt%,and the SiC skeleton became continuous with the SiC concentration reaching 20 wt%.The formation of continuous SiC skeleton improved the flexural strength of the composites effectively while keeping the TC in a high level.Especially,the composites with 30 wt%SiC exhibited the flexural strength up to 105 MPa,and the specific TC reaching 0.118 W·m^(2)·K^(−1)·kg-1.The composites with excellent flexural strength and thermophysical properties showed significant promise for thermal management applications.展开更多
文摘A novel super-hybrid composite (NSHC) is prepared with three-dimension reticulated SiC ceramic (3DRC), high performance carbon fibers and modified phenolic resin (BPR) in this paper. Ablation performance of super-hybrid composite is studied. The results show that the NSHC has less linear ablation rate compared with pure BPR and CF/BPR composite, for example, its linear ablation rate is 50% of CF/BPR at the same fiber content. Mass ablation rate of the NSHC is slightly lower than that of pure BPR and CF/BPR composite because of their difference in the density. Scanning electron microscopic analysis indicates that 3DRC can increase anti-erosion capacity of materials because its special reticulated structure can control the deformation of materials and strengthen the stability of integral structure.
基金Funded by the Project for Tackling Key Problems in Science and Technology of Wuhan(No.201262523841)
文摘Relationship between K2O-Al2O3-SiO2 system dental glass ceramics and Al2O3 ceramics was investigated. 4 groups of glass ceramic with the same components but different thickness（0.8, 1.2, 1.6, and 2.0 mm） were sintered on Al2O3 base ceramics according to the same thermal treatment system of leucite micro-crystallization reported in previous literatures. The products of each group were analyzed by polarizing microscope, X-ray diffractometer, and an INSTRON material testing machine. Under the thermal treatment system, leucite crystals were formed in samples of each group, and dispersed evenly. Meanwhile, the compressive strengths of group 3 and group 4 were higher than those of group 1 and group 2. Samples of group 3 showed better mechanical properties than others. The conclusions are drawn that Leucite crystals can be controlled in K2O-Al2O3-SiO2 system glass ceramic-Al2O3 ceramic composite material, and the thickness of glass ceramic has a notable influence on the compressive strength of this ceramic composite material.
基金This work was supported by the National Natural Science Foundation of China(Nos.51872222 and 92163112)the National Key R&D Program of China(No.2017YFB0310400)+1 种基金the Shaanxi Innovation Capacity Support Program(No.2018TD-031)the Research on Multi-Chip Parallel Current Sharing Technology of Power Electronic Devices Based on Electric-Thermal Optimization(No.SGAH0000KJJS1900437).
文摘Highly oriented graphite-based composites have attracted great attention because of their high thermal conductivity(TC),but the low mechanical properties caused by the inhomogeneous distribution and discontinuity of reinforcements restrict the wide applications.Herein,continuous SiC ceramic skeleton reinforced highly oriented graphite flake(SiC/GF)composites were successfully prepared by combining vacuum filtration and spark plasma sintering.The effect of SiC concentration on the microstructure,flexural strength,and thermophysical properties of the composites was investigated.The GF grains in the composites exhibited high orientation with a Lotgering factor of>88%when the SiC concentration was≤30 wt%,and the SiC skeleton became continuous with the SiC concentration reaching 20 wt%.The formation of continuous SiC skeleton improved the flexural strength of the composites effectively while keeping the TC in a high level.Especially,the composites with 30 wt%SiC exhibited the flexural strength up to 105 MPa,and the specific TC reaching 0.118 W·m^(2)·K^(−1)·kg-1.The composites with excellent flexural strength and thermophysical properties showed significant promise for thermal management applications.
