Ugbu a,silicon carbide (SiC)bụ ihe seramiiki na-eduzi thermally nke a na-amụsi ike n'ụlọ na ná mba ọzọ. The theoretical theormal conductivity nke SiC dị oke elu, na ụfọdụ ụdị kristal nwere ike iru 270W / mK, nke bụbu onye ndu n'etiti ihe ndị na-adịghị eduzi. Dịka ọmụmaatụ, enwere ike ịhụ ngwa nke SiC thermal conductivity na ihe ndị na-emepụta ihe nke ngwaọrụ semiconductor, ihe ndị na-ekpo ọkụ na-ekpo ọkụ nke seramiiki dị elu, ndị na-ekpo ọkụ na efere ọkụ maka nhazi semiconductor, ihe capsule maka mmanụ nuklia, na mgbanaka mkpuchi gas maka mgbapụta compressor.
Ngwa nkesilicon carbiden'ọhịa semiconductor
Diski na-egweri na ihe ndozi bụ ngwa usoro dị mkpa maka mmepụta silicon wafer na ụlọ ọrụ semiconductor. Ọ bụrụ na e ji ígwè nkedo ma ọ bụ carbon ígwè mee diski egweri, ndụ ọrụ ya dị mkpụmkpụ na ọnụọgụ mgbasawanye okpomọkụ ya dị ukwuu. N'oge nhazi nke silicon wafers, karịsịa n'oge elu-ọsọ egweri ma ọ bụ polishing, n'ihi na-eyi na thermal deformation nke egweri diski, flatness na parallelism nke silicon wafer siri ike nkwa. The egweri diski mere nkeceramics silicon carbidenwere obere iyi n'ihi ịdị elu ya dị elu, yana ọnụọgụ mgbasawanye ọkụ ya bụ otu ihe ahụ dị ka nke silicon wafers, yabụ enwere ike ịkụ ya ma kpochaa ya na oke ọsọ.
Tụkwasị na nke ahụ, mgbe a na-emepụta ihe ndị na-emepụta silicon, ha kwesịrị ịmalite ọgwụgwọ okpomọkụ dị elu ma na-ebufekarị ya site na iji silicon carbide fixtures. Ha na-eguzogide okpomọkụ na ndị na-adịghị ebibi. Enwere ike itinye diamond dị ka carbon (DLC) na mkpuchi ndị ọzọ n'elu iji kwalite arụmọrụ, belata mmebi wafer, ma gbochie mmetọ ịgbasa.
Ọzọkwa, dị ka onye nnọchiteanya nke ọgbọ nke atọ wide-bandgap semiconductor ihe, silicon carbide otu crystal ihe nwere ihe dị ka nnukwu bandgap obosara (ihe dị ka ugboro 3 nke Si), elu thermal conductivity (ihe dị ka 3.3 ugboro nke Si ma ọ bụ 10 ugboro). nke GaAs), ọnụ ọgụgụ mbugharị saturation eletrọn dị elu (ihe dị ka ugboro 2.5 nke Si) na ọkụ eletrik dị elu (ihe dị ka ugboro 10 nke Si ma ọ bụ ugboro ise nke GaAs). Ngwa SiC na-emepe maka ntụpọ nke ngwaọrụ ihe onwunwe semiconductor ọdịnala na ngwa bara uru ma na-eji nwayọọ nwayọọ na-aghọ isi nke semiconductor ike.
Ọchịchọ maka seramik silicon carbide dị elu abawanyela nke ukwuu
Site na mmepe sayensị na teknụzụ na-aga n'ihu, ọchịchọ maka ngwa nke ceramik silicon carbide na mpaghara semiconductor abawanyela nke ukwuu, yana ịdị elu thermal conductivity bụ isi ihe na-egosi ngwa ya na akụrụngwa nrụpụta semiconductor. Ya mere, ọ dị mkpa iji mee ka nyocha siri ike na seramiiki silicon carbide dị elu. Mbelata ọdịnaya oxygen nke lattice, imeziwanye njupụta, na iji ezi uche na-achịkwa nkesa nke abụọ n'ime lattice bụ ụzọ bụ isi iji melite conductivity thermal nke ceramics silicon carbide.
Ka ọ dị ugbu a, enwere ọmụmụ ole na ole gbasara seramik silicon carbide dị elu na mba m, ma a ka nwere nnukwu oghere ma e jiri ya tụnyere ọkwa ụwa. Ntuziaka nyocha n'ọdịnihu gụnyere:
● Mee ka nyocha usoro nkwadebe nke silicon carbide ceramic powder sie ike. Nkwadebe nke ịdị ọcha dị elu, ntụ ntụ silicon carbide dị ala bụ ihe ndabere maka nkwadebe nke ceramics silicon carbide dị elu nke thermal conductivity;
● Mee ka nhọrọ nke ihe enyemaka na-eme ka ọ dị ike na nyocha usoro ọmụmụ metụtara ya;
● Mee ka nyocha na mmepe nke ngwá ọrụ sintering dị elu. Site n'ịchịkwa usoro ịgbatị ahụ iji nweta microstructure ezi uche dị na ya, ọ bụ ọnọdụ dị mkpa iji nweta ceramics silicon carbide dị elu nke thermal conductivity.
Usoro iji melite thermal conductivity nke ceramik silicon carbide
Isi ihe na-eme ka nrụpụta thermal conductivity nke ceramics SiC bụ ibelata ugboro ịgbasa phonon na ịbawanye phonon pụtara ụzọ efu. A ga-emeziwanye conductivity thermal conductivity nke SiC nke ọma site n'ibelata porosity na oke oke ọka nke ceramics SiC, meziwanye ịdị ọcha nke oke ọka SiC, belata adịghị ọcha SiC lattice ma ọ bụ ntụpọ lattice, na ịbawanye ọkụ na-ebufe nnyefe ọkụ na SiC. Ka ọ dị ugbu a, ịkwalite ụdị na ọdịnaya nke ihe enyemaka na-eme ka ọ bụrụ ihe na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ bụ isi ihe na-eme ka okpomọkụ nke ceramics SiC dịkwuo mma.
① Na-ebuli ụdị na ọdịnaya nke ngwa ihe enyemaka
A na-agbakwunye ihe enyemaka dị iche iche mgbe a na-akwadebe ihe nrụpụta ọkụ dị elu nke ceramiki SiC. N'ime ha, ụdị na ọdịnaya nke ihe enyemaka nke sintering nwere mmetụta dị ukwuu na conductivity thermal nke ceramics SiC. Dịka ọmụmaatụ, ihe ndị Al ma ọ bụ O dị na Al2O3 usoro sintering enyemaka na-agbaze ngwa ngwa n'ime SiC lattice, na-ebute ohere na ntụpọ, nke na-eduga n'ịbawanye n'ọtụtụ oge mgbasa ozi phonon. Tụkwasị na nke ahụ, ọ bụrụ na ọdịnaya nke ihe ndị na-emepụta ihe na-eme ka ọ dị ala, ihe ahụ na-esiri ike ịmegharị na densify, ebe nnukwu ọdịnaya nke ihe ndị na-eme ka ọ dị elu ga-eduga n'ịbawanye adịghị ọcha na ntụpọ. Ihe enyemaka na-eme ka mmiri na-emebiga ihe ókè nwekwara ike igbochi uto nke ọka SiC ma belata ụzọ phonons efu. Ya mere, iji kwadebe elu thermal conductivity SiC ceramics, ọ dị mkpa iji belata ọdịnaya nke sintering enyemaka dị ka o kwere mee ka na-emezu ihe ndị a chọrọ nke sintering njupụta, na-agbalị na-ahọrọ sintering enyemaka nke siri ike igbari na SiC lattice.
* Njirimara okpomọkụ nke ceramik SiC mgbe agbakwunyere ihe enyemaka dị iche iche
Ugbu a, ceramics SiC na-ekpo ọkụ na-agbanye na BeO dị ka ihe enyemaka na-eme ka ọ bụrụ ihe na-eme ka ọ bụrụ ihe na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ (270W·m-1·K-1). Otú ọ dị, BeO bụ ihe na-egbu egbu nke ukwuu na carcinogenic, ọ dịghịkwa mma maka ngwa zuru ebe niile na ụlọ nyocha ma ọ bụ ubi mmepụta ihe. Ebe eutectic kachasị dị ala nke sistemụ Y2O3-Al2O3 bụ 1760 ℃, nke bụ enyemaka mmiri mmiri na-agba ọsọ maka seramiki SiC. Otú ọ dị, ebe ọ bụ na Al3 + na-agbaze ngwa ngwa n'ime SiC lattice, mgbe a na-eji usoro a eme ihe dị ka ihe enyemaka na-eme ka ọ bụrụ ihe na-eme ka ọ bụrụ ihe na-eme ka ọ bụrụ ihe na-eme ka ọ bụrụ ihe na-eme ka ọ bụrụ ihe na-eme ka ọ bụrụ ihe na-eme ka ọ bụrụ ihe na-eme ka ọ bụrụ ihe na-eme ka ọ bụrụ ihe na-ekpo ọkụ nke ụlọ nke SiC ceramics bụ ihe na-erughị 200W·m-1·K-1.
Ihe ndị na-adịghị ahụkebe nke ụwa dị ka Y, Sm, Sc, Gd na La anaghị adị mfe mgbaze na SiC lattice ma nwee nnukwu ikuku oxygen, nke nwere ike ibelata ọdịnaya oxygen nke SiC lattice nke ọma. Ya mere, Y2O3-RE2O3 (RE = Sm, Sc, Gd, La) usoro bụ ihe enyemaka na-emekarị maka ịkwadebe ihe ọkụkụ dị elu (> 200W · m-1 · K-1) ceramics SiC. Inweta enyemaka enyemaka Y2O3-Sc2O3 dị ka ihe atụ, uru ion deviation nke Y3+ na Si4+ buru ibu, ha abụọ anaghị enweta azịza siri ike. Solubility nke Sc na SiC dị ọcha na 1800 ~ 2600 ℃ dị obere, ihe dịka (2 ~ 3) × 1017atoms · cm-3.
② Ọgwụgwọ okpomọkụ dị elu
Ngwọta okpomọkụ dị elu nke ceramics SiC na-enyere aka ikpochapụ ntụpọ lattice, nkwụsịtụ na nrụgide fọdụrụnụ, na-akwalite mgbanwe nhazi nke ụfọdụ ihe amorphous na kristal, na-ebelata mmetụta mgbasa ozi phonon. Tụkwasị na nke ahụ, ọgwụgwọ okpomọkụ dị elu nwere ike ịkwalite ọganihu nke ọka SiC nke ọma, ma mechaa mee ka ihe ndị na-ekpo ọkụ na-ekpo ọkụ dị mma. Dịka ọmụmaatụ, mgbe ọgwụgwọ okpomọkụ dị elu na 1950 Celsius C, ọnụọgụ mgbasa ozi thermal diffusion nke SiC ceramics mụbara site na 83.03mm2 · s-1 ruo 89.50mm2 · s-1, na ikuku okpomọkụ nke ụlọ na-abawanye site na 180.94W · m. -1·K-1 ruo 192.17W·m-1·K-1. Ọgwụgwọ okpomọkụ dị elu na-eme ka ike deoxidation dịkwuo mma nke enyemaka sintering na elu SiC na lattice, ma mee ka njikọ dị n'etiti ọka SiC sie ike. Mgbe ọgwụgwọ okpomọkụ dị elu gasịrị, a na-emeziwanye ihe nrụpụta okpomọkụ nke ụlọ nke ceramics SiC.
Oge nzipu: Ọktoba 24-2024