Silicon Carbide Ceramic

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Silicon carbide ndi mtundu wa carbide yopanga yokhala ndi molekyulu ya SiC. Zikapatsidwa mphamvu, silika ndi kaboni nthawi zambiri zimapangidwira kutentha kwambiri kuposa 2000 ° C. Silicon carbide ili ndi kachulukidwe ka 3.18g/cm3, kuuma kwa Mohs komwe kumatsatira diamondi, ndi kulimba kwapakati kwa 3300kg/mm3 pakati pa 9.2 ndi 9.8. Chifukwa cha kuuma kwake kwakukulu komanso kukana kuvala kwapamwamba, kumakhala ndi zizindikiro za kutentha kwapamwamba ndipo zimagwiritsidwa ntchito pazinthu zosiyanasiyana zowonongeka, zowonongeka komanso zowonongeka kwambiri. Ndi mtundu watsopano waukadaulo wosamva kuvala wa ceramic.

1, Chemical katundu.

(1) Kukana kwa okosijeni: Pamene silicon carbide yakuthupi imatenthedwa mpaka 1300 ° C mumlengalenga, silicon dioxide protective layer imayamba kupangidwa pamwamba pa silicon carbide crystal. Ndi makulidwe a chitetezo cham'kati mwake, silicon carbide yamkati imapitilirabe oxidize, kotero kuti silicon carbide imakhala ndi kukana kwa okosijeni kwabwino. Kutentha kukafika kupitirira 1900K(1627 ° C), filimu yotetezera ya silicon dioxide imayamba kuwonongeka, ndipo makutidwe ndi okosijeni a silicon carbide amakula, kotero 1900K ndi kutentha kwa silicon carbide mumlengalenga wotsekemera.

(2) Kukana kwa Acid ndi alkali: chifukwa cha filimu yoteteza ya silicon dioxide, silicon carbide imakhala ndi gawo la filimu yoteteza ya silicon dioxide.

2, thupi ndi makina katundu.

(1) Kachulukidwe: The kachulukidwe tinthu zosiyanasiyana silicon carbide makhiristo ndi pafupi kwambiri, ambiri amaona kuti 3.20g/mm3, ndi masoka kulongedza kachulukidwe wa pakachitsulo carbide abrasives ndi pakati 1.2-1.6g/mm3, malinga tinthu kukula, kukula kwa tinthu ndi mawonekedwe a tinthu tating'onoting'ono.

(2) Kuuma: Kuuma kwa Mohs kwa silicon carbide ndi 9.2, kachulukidwe kakang'ono ka Wessler ndi 3000-3300kg/mm2, kuuma kwa Knopp ndi 2670-2815kg/mm, abrasive ndi apamwamba kuposa corundum, pafupi ndi diamondi, cubic. boron nitride ndi boron carbide.

(3) Matenthedwe matenthedwe: zopangidwa ndi silicon carbide zimakhala ndi matenthedwe apamwamba kwambiri, machulukidwe ang'onoang'ono amafuta, kukana kugwedezeka kwamafuta, ndipo ndi zida zapamwamba zokanira.

3, Mphamvu zamagetsi.

Kanthu Chigawo Deta Deta Deta Deta Deta
RBsic (sisic) NBSiC SSiC Mtengo wa RSiC OSiC
Zinthu za SiC % 85 76 99 ≥99 ≥90
Zaulere za silicon % 15 0 0 0 0
Kutentha kwakukulu kwa utumiki 1380 1450 1650 1620 1400
Kuchulukana g/cm3 3.02 2.75-2.85 3.08-3.16 2.65-2.75 2.75-2.85
Open porosity % 0 13-15 0 15-18 7-8
Mphamvu yopindika 20 ℃ Mpa 250 160 380 100 /
Mphamvu yopindika 1200 ℃ Mpa 280 180 400 120 /
Modulus ya elasticity 20 ℃ Gpa 330 580 420 240 /
Modulus ya elasticity 1200 ℃ Gpa 300 / / 200 /
Thermal conductivity 1200 ℃ W/mk 45 19.6 100-120 36.6 /
Coefficient of thermaleexpansion K^-lx10^-8 4.5 4.7 4.1 4.69 /
HV kg/m2 2115 / 2800 / /