The structure and phase condition's evolution in the silicon carbide ceramics surface layer under the electron-beam treatment

The elemental constituents, phase composition and substructural evolution were investigated in the article in the silicon carbide ceramics surface layer which was subjected to the intense pulsed electron beam the density of the electron beam being varied. It was shown that the ceramic layer surface's structure and phase conditions were controlled by the electron beam characteristics. The SiC-ceramics surface layer nanostructuring was detected and the electron beam treatment conditions which lead to this effect were defined.

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Optimal preparation of high-entropy boride-silicon carbide ceramics

10.21203/rs.3.rs-33290/v2 ◽

2020 ◽

Author(s):

Yan Zhang ◽

Shi-Kuan Sun ◽

Wei-Ming Guo ◽

Liang Xu ◽

Wei Zhang ◽

...

Keyword(s):

Silicon Carbide ◽

Carbothermal Reduction ◽

Powder Processing ◽

Full Density ◽

High Entropy ◽

Sic Ceramics ◽

Reduction Methods ◽

Borothermal Reduction ◽

Carbide Ceramics ◽

Silicon Carbide Ceramics

Abstract High-entropy boride-silicon carbide (HEB-SiC) ceramics were fabricated by using boride-based powders prepared from borothermal and boro/carbothermal reduction methods. The effects of processing routes (borothermal reduction and boro/carbothermal reduction) of HEB powders were examined. HEB-SiC ceramics with nearly relatively full density (>98%) were prepared by spark plasma sintering at 2000oC. It was demonstrated that the addition of SiC led to slightly coarsening of the microstructure. The HEB-SiC ceramics prepared from boro/carbothermal reduction powders showed the fine-grained microstructure and higher Vickers’ hardness but lower fracture toughness values as compared with the same composition prepared from borothermal reduction powders. These results indicated that the selection of the powder processing method and the addition of SiC phase could contribute to the optimal preparation of high-entropy boride-based ceramics.

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Nano-Grained Microstructure Design of Silicon Carbide Ceramics by SPS Process

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.403.177 ◽

2008 ◽

Vol 403 ◽

pp. 177-178

Author(s):

Junichi Hojo ◽

Hiroyuki Matsuura ◽

Mikinori Hotta

Keyword(s):

Silicon Carbide ◽

Grain Growth ◽

Microstructure Design ◽

Sic Ceramics ◽

Heating Schedule ◽

Optimum Heating ◽

Carbide Ceramics ◽

Silicon Carbide Ceramics

SiC ceramics were fabricated from submicron- and nano-sized starting powders with Y2O3 and AlN additives by SPS process. The SPS process and the use of AlN additive were found to be effective for achieving the nano-grained microstructure with retarded grain growth. The nanoporous SiC ceramics were also obtained under the similar conditions. The optimum heating schedule and additive composition were proposed.

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Microstructure and Mechanical Properties of Heat-Resistant Silicon Carbide Ceramics

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.336-338.1409 ◽

2007 ◽

Vol 336-338 ◽

pp. 1409-1413 ◽

Cited By ~ 2

Author(s):

Young Wook Kim ◽

Yong Seong Chun ◽

Sung Hee Lee ◽

Ji Yeon Park ◽

Toshiyuki Nishimura ◽

...

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Silicon Carbide ◽

Intergranular Phase ◽

Sintering Additives ◽

Heat Resistant ◽

Sic Ceramics ◽

Microstructure And Mechanical Properties ◽

Carbide Ceramics ◽

Silicon Carbide Ceramics

There has been a great progress in the development of heat-resistant silicon carbide ceramics, owing to the better understanding of composition-microstructure-properties relations. Based on the progress, it has been possible to fabricate heat-resistant SiC ceramics with improved fracture toughness. In this paper, three rare-earth oxides (Re2O3, Re=Er, Lu, and Sc) in combination with AlN were used as sintering additives for a β-SiC containing 1 vol% α-SiC seeds. The effect of intergranular phase, using Re2O3 and AlN as sintering additives, on the microstructure and mechanical properties of liquid-phasesintered, and subsequently annealed SiC ceramics were investigated. The microstructure and mechanical properties were strongly influenced by the sintering additive composition, which determines the chemistry and structure of IGP. The strength and fracture toughness of the Lu2O3-doped SiC were ∼700 MPa at 1400oC and ∼6 MPa.m1/2 at room temperature, respectively. The beneficial effect of the new additive compositions on high-temperature strength was attributed to the crystallization of the intergranular phase.

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Optimal preparation of high-entropy boride-silicon carbide ceramics

Journal of Advanced Ceramics ◽

10.1007/s40145-020-0418-1 ◽

2020 ◽

Author(s):

Yan Zhang ◽

Shi-Kuan Sun ◽

Wei-Ming Guo ◽

Liang Xu ◽

Wei Zhang ◽

...

Keyword(s):

Silicon Carbide ◽

Carbothermal Reduction ◽

Powder Processing ◽

High Entropy ◽

Fine Grained ◽

Sic Ceramics ◽

Reduction Methods ◽

Borothermal Reduction ◽

Carbide Ceramics ◽

Silicon Carbide Ceramics

Abstract High-entropy boride-silicon carbide (HEB-SiC) ceramics were fabricated using boride-based powders prepared from borothermal and boro/carbothermal reduction methods. The effects of processing routes (borothermal reduction and boro/carbothermal reduction) on the HEB powders were examined. HEB-SiC ceramics with > 98% theoretical density were prepared by spark plasma sintering at 2000 °C. It was demonstrated that the addition of SiC led to slight coarsening of the microstructure. The HEB-SiC ceramics prepared from boro/carbothermal reduction powders showed a fine-grained microstructure and higher Vickers’ hardness but lower fracture toughness value as compared with the same composition prepared from borothermal reduction powders. These results indicated that the selection of the powder processing method and the addition of SiC phase could contribute to the optimal preparation of high-entropy boride-based ceramics.

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Analytical Prediction of Subsurface Damages and Surface Quality in Vibration-Assisted Polishing Process of Silicon Carbide Ceramics

Materials ◽

10.3390/ma12101690 ◽

2019 ◽

Vol 12 (10) ◽

pp. 1690

Author(s):

Yan Gu ◽

Yan Zhou ◽

Jieqiong Lin ◽

Allen Yi ◽

Mingshuo Kang ◽

...

Keyword(s):

Silicon Carbide ◽

Analytical Prediction ◽

Polishing Process ◽

Brittle Ductile Transition ◽

Sic Ceramics ◽

Element Simulation ◽

Critical Cutting Depth ◽

Hard And Brittle Materials ◽

Carbide Ceramics ◽

Silicon Carbide Ceramics

Subsurface damages and surface roughness are two significant parameters which determine the performance of silicon carbide (SiC) ceramics. Subsurface damages (SSD) induced by conventional polishing could seriously affect the service life of the workpiece. To address this problem, vibration-assisted polishing (VAP) was developed to machine hard and brittle materials, because the vibration-assisted machine (VAM) can increase the critical cutting depth to improve the surface integrity of materials. In this paper, a two-dimensional (2D) VAM system is used to polish SiC ceramics. Moreover, a theoretical SSD model is constructed to predict the SSD. Furthermore, finite element simulation (FEM) is adopted to analyze the effects of different VAP parameters on SSD. Finally, a series of scratches and VAP experiments are conducted on the independent precision polishing machine to investigate the effects of polishing parameters on brittle–ductile transition and SSD.

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Effects of Additives Content on the Properties of Porous SiC Ceramics

Materials Science Forum ◽

10.4028/www.scientific.net/msf.868.89 ◽

2016 ◽

Vol 868 ◽

pp. 89-94

Author(s):

Rong Li ◽

Rong Zhen Liu ◽

Gao Jian Liu ◽

Zhi Hao Jin

Keyword(s):

Silicon Carbide ◽

Melting Point ◽

Porous Silicon ◽

Bending Strength ◽

Porous Silicon Carbide ◽

Sic Ceramics ◽

Proportional Relationship ◽

Carbide Ceramics ◽

Porous Sic ◽

Silicon Carbide Ceramics

The porous silicon carbide ceramics were fabricated by adding a variety of low melting point oxides in this paper. The additives were mullite, magnesium oxide, calcium oxide, and vanadium oxide. Effects of the additives content on the properties of porous silicon carbide ceramics were studied. The results showed that, when the additives content was greater than 2.8%, the apparent porosity, the bending strength, the permeability and the pore size were in an inversely proportional relationship with the additives content, while the content was less than 2.8%, proportional relationship was observed. When the additives content reached 2.8%, the porous SiC ceramics showed the best performances.

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Optimal preparation of high-entropy boride-silicon carbide ceramics

10.21203/rs.3.rs-33290/v3 ◽

2020 ◽

Author(s):

Yan Zhang ◽

Shi-Kuan Sun ◽

Wei-Ming Guo ◽

Liang Xu ◽

Wei Zhang ◽

...

Keyword(s):

Silicon Carbide ◽

Carbothermal Reduction ◽

Powder Processing ◽

Full Density ◽

High Entropy ◽

Sic Ceramics ◽

Reduction Methods ◽

Borothermal Reduction ◽

Carbide Ceramics ◽

Silicon Carbide Ceramics

Abstract High-entropy boride-silicon carbide (HEB-SiC) ceramics were fabricated by using boride-based powders prepared from borothermal and boro/carbothermal reduction methods. The effects of processing routes (borothermal reduction and boro/carbothermal reduction) of HEB powders were examined. HEB-SiC ceramics with nearly relatively full density (>98%) were prepared by spark plasma sintering at 2000 °C. It was demonstrated that the addition of SiC led to slightly coarsening of the microstructure. The HEB-SiC ceramics prepared from boro/carbothermal reduction powders showed the fine-grained microstructure and higher Vickers’ hardness but lower fracture toughness values as compared with the same composition prepared from borothermal reduction powders. These results indicated that the selection of the powder processing method and the addition of SiC phase could contribute to the optimal preparation of high-entropy boride-based ceramics.

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Effect of Pulsed Electron Beam Treatment and Hydrogen on Properties of Zirconium Alloy

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.302.66 ◽

2013 ◽

Vol 302 ◽

pp. 66-71 ◽

Cited By ~ 3

Author(s):

N.S. Pushilina ◽

Ekaterina N. Stepanova ◽

E.V. Berezneeva ◽

A.M. Lider ◽

Ivan P. Chernov ◽

...

Keyword(s):

Surface Layer ◽

Electron Beam ◽

Phase Composition ◽

Hydrogen Absorption ◽

Zirconium Alloy ◽

Electron Beam Treatment ◽

Pulsed Electron Beam ◽

Complex Morphology ◽

Modified Surface

The paper presents the results of the pulsed beam effect on the structure and phase composition of zirconium alloy. Such treatment is demonstrated to lead to forming of complex morphology martensite in the surface layer of the alloy. The processes of hydrogen absorption by zirconium alloy with modified surface have been studied. Modification of the samples is found to reduce the amount of hydrogen, absorbed by the volume of zirconium alloy during hydrogenation.

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Effect of solid loading on properties of reaction bonded silicon carbide ceramics by gelcasting

RSC Advances ◽

10.1039/c4ra05817h ◽

2014 ◽

Vol 4 (92) ◽

pp. 50386-50392 ◽

Cited By ~ 4

Author(s):

Zhiyong Yuan ◽

Yumin Zhang ◽

Yufeng Zhou ◽

Shanliang Dong

Keyword(s):

Silicon Carbide ◽

Furfuryl Alcohol ◽

Phenol Formaldehyde ◽

Phenol Formaldehyde Resin ◽

Solid Loading ◽

Formaldehyde Resin ◽

Sic Ceramics ◽

Low Toxicity ◽

Carbide Ceramics ◽

Silicon Carbide Ceramics

Reaction bonded silicon carbide (SIC) ceramics were successfully fabricated by gelcasting using a new non-aqueous, low-toxicity gel system based on the polymerization of a phenol-formaldehyde resin and furfuryl alcohol.

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