Recrystallized Silicon Carbide

Silicon carbide shapes with a high green density made by shp casting or by pressmolding SiC powders of bimodal particle size distribution are fired in an electric furnace at temperatures of up to 2500 °C, under the exdusion of air [165, 166). Evaporation and condensation take place at temperatures above 2100 °C, and this 

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The resistance of ceramically bonded and recrystallized silicon carbide to thermal shock, oxidation, and corrosion is utilized in its use as a refractory construction... 

Mechanical properties Symbol Units Silicon carbide, sintered Silicon carbide, silicon- infiltrated Silicon carbide, recrystallized Silicon carbide, nitride-bonded Boron carbide... 

PIN, PIP, POST (or prop), printer s bit, RING, SADDLE, SAGGAR, SETTER, SPUR, STILT, thimble see also Fig. 4. As well as fireclay refractory, recrystallized silicon carbide and nickel metal have been used. 

Bricks of silicon carbide, either recrystallized or clay-bonded, have a high thermal conductivity and find use in muffle walls and as a slag-resisting material. 

Microwave technology has also been used for the Dimroth rearrangement of the aminothiazine 964 to the pyrimid-inethione 965. The optimized conditions involved heating a solution of the thiaztne 964 in toluene together with a silicon carbide heating element at 220°C for 30min to provide a 68% product yield after recrystallization <2006JOC4651>. 

Method 2 produces what is usually referred to as self-bonded SiC by a process essentially the same as that developed for nuclear applications [2] and known as Refel silicon carbide. Refel silicon carbide contains a finely dispersed residual silicon phase accounting for between 5 and 10% of the total volume, the precise amount depending upon the porosity of the original preform. In the case of self-bonded silicon carbide elements the residual silicon is volatilized away by a final heat-treatment at over 2500 °C when recrystallization occurs resulting in grain growth and further bonding between primary and secondary carbide phases. 

Crystar. Tradename. A form of RECRYSTALLISED SILICON CARBIDE (q.v.) in which SiC and electronic grade Si react at over 2300 °C, and the grains recrystallize to form a continuous network of SiC. Crystar is used to produce thermal shock resistant kiln furniture as well as tubes and other refractory shapes. (Norton Co, USA). C-Scan Acoustic Microscopy, C SAM. Focussed transducers from 10 to 100 MHz are coupled to the test piece in a water-immersion tank so that the test-piece is located at the desired depth below the test-piece surface. (The reflections from that surface itself are cut out electronically). Scanning the transducer over the surface produces an image of internal flaws at that depth in the specimen. 

For most of applications, it is required to purity BPA from the mentioned byproducts before its further processing. Therefore, the BPA production line consists of a condensation reactor and the units responsible for the BPA purification. Among them, there is usually a unit for crystallization of the BPA-phenol adduct and stripping tower, where the adduct is cracked and phenol is recovered (as it was described earlier). There are also a recrystallization unit, a cracker for the o,p-isomers of BPA and a wastewater treatment facility. Additionally, there may be an isomerization unit, where the mother liquor is contacted with an acidic or amine-based ion-exchange resin as the isomerization catalyst under the conditions effective to convert the BPA byproducts to BPA. Next, the effluent from the isomerization zone can be contacted with a solid particle guard bed, composed of alumina, titanium oxide, silica, zirconium oxide, tin oxide, charcoal or silicon carbide [55]. This guard... 

V Heera, R Kogler and W Skorupa, Complete recrystallization of amorphous silicon carbide layers by ion irradiation, Appl. Phys. Lett. 67 1999-2001 (1995)... 

A Hofgen, V Heera, F Eicchom and W Skorupa, Annealing and recrystallization of amorphous silicon carbide produced by ion implantation, J. Appl. Phys. 84 4769-74 (1998)... 

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