Jun QIU
,
Xiaoming CAO
,
Chong TIAN
,
Jinsong ZHANG
材料科学技术（英）
A novel super-hybrid composite (NSHC) was boron-modified phenolic resin (BPR) with three-dimensional reticulated SiC ceramic (3DRC) and high silica fibers. Ablation performance of the NSHC was studied. The results show that the linear ablation rate of NSHC was lower than that of pure BPR and the high silica/BPR composite. Its linear ablation rate is 1/17 of the high silica/BPR. Mass ablation rate of the NSHC is very close to that of the pure BPR and the high silica/BPR composite. Scanning electron microscope (SEM) analysis indicates that 3DRC has scarcely changed its shape at the ablation temperature. Its special reticulated structure can restrict the materials deformation and prevent high velocity heat flow from eroding the surface of the materials largely and thus increase ablation resistance of the NSHC.
关键词:
Ablation performance
,
null
,
null
,
null
Jun QIU
,
Xiaoming CAO
,
Chong TIAN
,
Jinsong ZHANG
材料科学技术（英）
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.
关键词:
Ablation performance
,
null
,
null
Qing GONG
,
Xiaoming CAO
,
Jinsong ZHANG
,
Zheng FANG
材料科学技术（英）
3D reticulated ceramics (3DRCs) with the composition containing SrFe12O19-SiC-TiO2 were prepared by a replication process with polyurethane sponges as the template in ceramic slurry. The electrical conductivity, dielectric and magnetic parameters of 3D reticulated ceramics (3DRCs) were measured with changes in cell size of the sponges, contents in the slurry and sintering temperature in this paper. Discussions about the influential factors of those parameters were focused on their electrical conductivity. The experimental results indicated that the electrical conductivity of 3DRCs raised with the increase of cell size, SiC/SrO·6Fe2O3 with weight ratio and sintering temperature. X-ray diffractions and SEM were used to investigate the relationship between electrical conductivity and sintering temperature. Deoxidizing reactions of SrO·6Fe2O3 caused the increasing electrical conductivity. The real part of permittivity (ε') and imaginary part of permeability (μ'') raised with the increase of electrical conductivity (σ). The imaginary part of permittivity (ε'') has a maximum at 100S/cm with the increase of sigma, and the real part of permeability (μ') changes slightly with the increase ofσ. When sigma is at the range of 10-4 S/cm to 100 S/cm (a semi conductive state), both the imagine part of permittivity and permeability raises with increasing sigma, therefore, the 3DRCs present their high electromagnetic loss properties.
关键词:
3D reticulated ceramics
,
null
,
null
,
null
