1. Crystallography na ụkpụrụ ihe onwunwe nke Silicon Carbide
1.1 Polymorphism na Atomic Bonding na SiC
(Efere seramiiki Silicon Carbide)
Silicon carbide (SiC) bụ ngwakọta seramiiki covalent mejupụtara silicon na carbon carbon na a 1:1 oke stoichiometric, pụrụ iche site na ya ịtụnanya polymorphism– gafere 250 polytypes a ma ama– niile na-ekekọrịta njikọ ntụzịaka siri ike mana ọ dị iche iche n'usoro stacking nke Si-C bilayers.
Otu n'ime ụdị polytype kachasị dabara na teknụzụ bụ 3C-SiC (cubic zinc blende Ọdịdị), na ụdị hexagonal 4H-SiC na 6H-SiC, nke ọ bụla na-egosi ọdịiche a nụchara anụcha na bandgap, eletrọn mgbanwe, na thermal conductivity nke na-emetụta ike ha maka ngwa ngwa.
Ike nke Si– C nkekọ, na ike nkekọ nke gburugburu 318 kJ/mol, na-akwado nkwado siri ike nke SiC (Mohs siri ike nke 9– 9.5), nnukwu agbaze ihe (~ 2700 Celsius C), na iguzogide mmebi kemịkalụ na ujo thermal.
Na efere seramiiki, a na-ahọrọkarị ụdị polytype dabere n'ihe eji eme ya: 6H-SiC na-emeri na ngwa ụlọ n'ihi ịdị mfe nke njikọ ya, ebe 4H-SiC na-achị na ngwa elektrọnịk dị elu maka mgbanwe ndị na-ebu ụgbọ ya pụrụ iche.
Nnukwu bandgap (2.9– 3.3 eV dabere na polytype) na-emekwa SiC ka ọ bụrụ ezigbo ihe mkpuchi eletrik n'ụdị ya dị ọcha, ọ bụ ezie na enwere ike doped ya ka ọ rụọ ọrụ dị ka semiconductor na ngwaọrụ eletrọnịkị pụrụ iche.
1.2 Microstructure na ọkwa dị ọcha na efere seramiiki
Ịrụ ọrụ nke efere seramiiki silicon carbide dabere na njiri mara microstructural dị ka akụkụ ọka., ọkpụrụkpụ, ogbo homogeneity, na visibiliti nke abụọ nkebi ma ọ bụ adịghị ọcha.
A na-emepụta efere dị elu site na submicron ma ọ bụ nanoscale SiC powders site na ụzọ nrịgo elu., na-eme ka ọ dị mma, zuru ezu ok microstructures na ebuli n'ibu ike na thermal conductivity.
Ihe na-emetọ ihe dị ka carbon complimentary, silica (SiO ₂), ma ọ bụ enyemaka singing dị ka boron ma ọ bụ aluminom ga-ejizi nke ọma chịkwaa, dị ka ha nwere ike na-etolite intergranular nkiri na ibelata elu-okpomọkụ ike na ọxịdashọn iguzogide.
Mfọdu porosity, ọbụlagodi na ọkwa dị ala (
Advanced Ceramics tọrọ ntọala na October 17, 2012, bụ ụlọ ọrụ teknụzụ dị elu kwadoro nyocha na mmepe, mmepụta, nhazi, ahịa na ọrụ nka nke ihe ndị ikwu seramiiki dị ka Silicon Carbide Ceramic Plates. Ngwaahịa anyị gụnyere mana ọnweghị oke na ngwaahịa seramiiki Boron Carbide, Ngwaahịa seramiiki boron nitride, Ngwaahịa seramiiki Silicon Carbide, Ngwaahịa seramiiki silicon Nitride, Ngwaahịa seramiiki Zirconium Dioxide, wdg. Ọ bụrụ na ị nwere mmasị, biko nweere onwe gị ịkpọtụrụ anyị.
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