scholarly journals Complex elements of aerospace equipment from reaction silicon carbide ceramics

2020 ◽  
Vol 64 (6) ◽  
pp. 730-738
Author(s):  
A. Ph. Ilyushchenko ◽  
L. N. Dyachkova ◽  
V. A. Osipov
Keyword(s):  
Silicon Carbide ◽  
Braze Alloy ◽  
The Body ◽  
Carbide Powder ◽  
Complex Profile ◽  
Optical Telescope ◽  
Profile Element ◽  
Carbide Ceramics ◽  
Silicon Carbide Ceramics ◽  
Silicon Carbide Powder

The results of studying the process of obtaining complex-profile elements of the substrate of mirrors of optical telescopes from reaction-sintered silicon carbide ceramics are presented. It is shown that the strength of silicon carbide ceramics depends on the dispersion of the silicon carbide powder and on the temperature of reaction sintering. An increase in the sintering temperature from 1500 to 1650 °C leads to an increase in strength by 60 MPa, and to 1800 °C – to a decrease in strength by 40 MPa. An increase in strength is explained by a decrease in free silicon and an increase in the content of secondary silicon carbide, a decrease in strength is explained by an increase in the size of carbide grains. The study of the influence of the modes of soldering of hexagonal elements to obtain a complex-profile element of the substrate of the mirror of an optical telescope on the strength of the soldered seam showed that the introduction of silicon carbide powder 7 μm in size and amorphous boron in an amount of 6 % into the solder composition based on silicon carbide has a positive effect on the strength of the soldered seam. Tests of the brazed specimens at three-point bending showed that fracture occurs along the body of the specimens being brazed, and not the brazed seam. The structure of the brazed joint depends on the composition of the braze alloy and the gap between the samples to be brazed.

Biomorphic Silicon Carbide Ceramics Coated with Bioactive Glass for Medical Applications

2006 ◽  
Vol 514-516 ◽  
pp. 970-974 ◽  
Author(s):  
Jacinto P. Borrajo ◽  
Pio González ◽  
Julia Serra ◽  
Sara Liste ◽  
Stefano Chiussi ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Bioactive Glass ◽  
The Body ◽  
Bioactive Materials ◽  
Bioactive Coatings ◽  
Metallic Substrates ◽  
New Material ◽  
Carbide Ceramics ◽  
Silicon Carbide Ceramics

There is a need to develop new tough bioactive materials capable to withstand high loads when implanted in the body and with improved fixation, which led to the production of bioactive coatings on metallic substrates. A new approach, which consists of biomorphic silicon carbide (SiC) coated with bioactive glass, was recently presented. This new material joins the high mechanical strength, lightness and porosity of biomorphic SiC, and the bioactive properties of PLD glass films. In this work, a multiple evaluation in terms of biocompatibility of this new material was carried out starting from the biomorphic SiC morphology and porosity, following with the bioactivity of the coatings in simulated body fluid, and ending with a deep biocompatibility study with MG-63 cells. Different ranges of porosity and pore size were offered by the biomorphic SiC depending on the starting wood. The PLD glassy coatings had a high bioactivity in vitro and both the biomorphic SiC coated and uncoated presented high levels of biocompatibility.

Effects of Vickers Cracks on the Mechanical Properties of Solid-phase-sintered Silicon Carbide Ceramics

2012 ◽  
Vol 27 (9) ◽  
pp. 965-969
Author(s):  
Xiao YANG ◽  
Xue-Jian LIU ◽  
Zheng-Ren HUANG ◽  
Gui-Ling LIU ◽  
Xiu-Min YAO
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Solid Phase ◽  
Carbide Ceramics ◽  
Silicon Carbide Ceramics ◽  
Sintered Silicon

Vickers indentation crack analysis of solid-phase-sintered silicon carbide ceramics

2013 ◽  
Vol 39 (1) ◽  
pp. 841-845 ◽  
Author(s):  
Xiao Yang ◽  
Xuejian Liu ◽  
Zhengren Huang ◽  
Xiuming Yao ◽  
Guiling Liu
Keyword(s):  
Silicon Carbide ◽  
Solid Phase ◽  
Vickers Indentation ◽  
Crack Analysis ◽  
Indentation Crack ◽  
Carbide Ceramics ◽  
Silicon Carbide Ceramics ◽  
Sintered Silicon

scholarly journals Surface Nitridation of Silicon Carbide Ceramics

1989 ◽  
Vol 97 (1131) ◽  
pp. 1348-1353
Author(s):  
Tadahisa ARAHORI ◽  
Nobuya IWAMOTO
Keyword(s):  
Silicon Carbide ◽  
Carbide Ceramics ◽  
Silicon Carbide Ceramics

scholarly journals High-temperature oxidation behavior of reaction-formed silicon carbide ceramics

1995 ◽  
Vol 10 (12) ◽  
pp. 3232-3240 ◽  
Author(s):  
Linus U.J.T. Ogbuji ◽  
M. Singh
Keyword(s):  
Silicon Carbide ◽  
Weight Loss ◽  
Oxidation Product ◽  
Oxidation Behavior ◽  
Light And Electron Microscopy ◽  
Initial Weight Loss ◽  
Temperature Oxidation ◽  
Carbide Ceramics ◽  
High Temperature Oxidation Behavior ◽  
Silicon Carbide Ceramics

The oxidation behavior of reaction-formed silicon carbide (RFSC) ceramics was investigated in the temperature range of 1100 to 1400 °C. The oxidation weight change was recorded by TGA; the oxidized materials were examined by light and electron microscopy, and the oxidation product by x-ray diffraction analysis (XRD). The materials exhibited initial weight loss, followed by passive weight gain (with enhanced parabolic rates, kp), and ending with a negative (logarithmic) deviation from the parabolic law. The weight loss arose from the oxidation of residual carbon, and the enhanced kp values from internal oxidation and the oxidation of residual silicon, while the logarithmic kinetics is thought to have resulted from crystallization of the oxide. The presence of a small amount of MoSi2 in the RFSC material caused a further increase in the oxidation rate. The only solid oxidation product for all temperatures studied was silica.

Resonant ultrasound spectroscopy of silicon carbide ceramics SiC‒AlN

2021 ◽  
pp. 136-140
Author(s):  
E. G. Pashuk ◽  
G. D Kardashova ◽  
Sh. A. Khalilov
Keyword(s):  
Silicon Carbide ◽  
Elastic Moduli ◽  
Ultrasonic Spectroscopy ◽  
Resonant Ultrasound Spectroscopy ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Complete Set ◽  
Resonant Ultrasound ◽  
Carbide Ceramics ◽  
Silicon Carbide Ceramics

The paper discusses the possibility of using resonant ultrasonic spectroscopy (RUS) as a source of information for the physics and technology of obtaining silicon carbide ceramics by the example of samples of the composition SiC ‒ 25 % AlN, obtained by the method of spark plasma sintering. The possibility of obtaining a complete set of elastic moduli (EM) of samples with an error of less than 1 % is shown. At the same time, the requirements for surface quality are significantly reduced. The revealed functional relationship between EM and porosity makes it possible to create a non-destructive method of porosity control and calculate the elastic moduli at zero porosity (i. e., the elastic modulus of the ceramic matrix EM0). Comparison of EM0 samples obtained at different parameters of the technological process allows determining their optima values..

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