Microwave Curing of Silicon Carbide Ceramics from a Polycarbosilane Precursor

1994 ◽  
Vol 347 ◽  
Author(s):  
Tzyy-Heng Alex Shan ◽  
Robert Cozzens

ABSTRACTSilicon carbide ceramic materials have been successfully formed from commercially available polycarbosilane using microwave radiation as the sole source of heat. Conventional thermal processing of the same polymeric precursor was also studied for comparison with microwave processing. Microwave heating enhances crystallinity at much lower curing temperature and within shorter times. Possible explanations for microwave enhanced processing are proposed.

2012 ◽  
Vol 727-728 ◽  
pp. 821-825 ◽  
Author(s):  
Rodrigo Mende Mesquita ◽  
Ana Helena de Almeida Bressiani

Silicon carbide is used to produce abrasive and high-temperature structural ceramic materials due to its mechanical and chemical properties. The possible applications of porous silicon carbide ceramics are diesel engines catalysers and molten metal filters. In the last years the starch gained importance as a pore-forming and consolidation agent, due to it is environmental friendly and easily processing. The current work uses starch (corn, rice and potato) as pore forming and consolidation agent. The samples sintered at different sintering times were characterized by density and microstructure (XRD, SEM). The results show that the samples presented porosity between 20 and 40% and the microstructures obtained is homogeneous with a pore size similar to the starch particle added.


2013 ◽  
Vol 416-417 ◽  
pp. 1693-1697 ◽  
Author(s):  
Bing Feng Liu

Ceramic industry developed rapidly in recent years, a greater demand for new materials. SiC ceramics as one of candidate materials that a few suitable for use high-temperature structural parts, shows its unique advantages in the high temperature, thermal shock, corrosive and other harsh environments. Its high temperature performance and application potential has attracted people's attention, but its properties make it difficult sintering at atmospheric pressure, unable to meet the needs of industrial production. Pressure less sintering technology has become the key in its application promotion. As strong antioxidant activity, better abrasion resistance, hardness, thermal stability, high temperature strength, thermal expansion coefficient, thermal conductivity and thermal shock and great chemical resistance and other excellent characteristics, Silicon carbide ceramics are widely used in various fields. Based on the silicon carbide ceramic materialisms development process, characteristics, international research and proposed several status of sintering silicon carbide ceramic, and discuss its development trends.


2012 ◽  
Vol 562-564 ◽  
pp. 27-30
Author(s):  
Zhu Xing Tang ◽  
Hui Hui Tan ◽  
He Zhang ◽  
Ke Zhou Xu ◽  
Ying Zhang

The Si¬2ON2-SiC ceramic was fabricated by pressureless sintering method. In this paper we researched the effect of SiC content (50%, 70% and 90%) on the performance of silicon oxynitride bonded silicon carbide ceramics. Through testing and analyzing the SEM, XRD, density and porosity of the final silicon oxynitride bonded silicon carbide ceramic samples, the results show that: changes in SiC content not only affect the bulk density of the composites but also affect the phase composition and the microstructure of fracture surface. The most compactness experimental product is sintered at1500°C containing 50wt% SiC.


2012 ◽  
Vol 27 (9) ◽  
pp. 965-969
Author(s):  
Xiao YANG ◽  
Xue-Jian LIU ◽  
Zheng-Ren HUANG ◽  
Gui-Ling LIU ◽  
Xiu-Min YAO

2013 ◽  
Vol 39 (1) ◽  
pp. 841-845 ◽  
Author(s):  
Xiao Yang ◽  
Xuejian Liu ◽  
Zhengren Huang ◽  
Xiuming Yao ◽  
Guiling Liu

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

1995 ◽  
Vol 10 (12) ◽  
pp. 3232-3240 ◽  
Author(s):  
Linus U.J.T. Ogbuji ◽  
M. Singh

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.


Author(s):  
E. G. Pashuk ◽  
G. D Kardashova ◽  
Sh. A. Khalilov

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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