Panopa,silicon carbide (SiC)ndi thermally conductive ceramic zakuthupi zomwe zimaphunziridwa mwachangu kunyumba ndi kunja. The theoretical thermal conductivity ya SiC ndi yokwera kwambiri, ndipo mawonekedwe ena a kristalo amatha kufika ku 270W / mK, yomwe ili kale mtsogoleri pakati pa zinthu zopanda conductive. Mwachitsanzo, ntchito ya SiC matenthedwe madutsidwe tingaone mu gawo lapansi zipangizo za semiconductor zipangizo, mkulu matenthedwe madutsidwe ceramic zipangizo, heaters ndi Kutentha mbale kwa semiconductor processing, zipangizo kapisozi mafuta nyukiliya, ndi mpweya kusindikiza mphete kwa mapampu kompresa.
Kugwiritsa ntchito kwasilicon carbidem'munda wa semiconductor
Ma disks okupera ndi zida ndizofunikira kwambiri popanga silicon wafer mumakampani opanga semiconductor. Ngati chimbale chogaya chimapangidwa ndi chitsulo choponyedwa kapena chitsulo cha carbon, moyo wake wautumiki ndi waufupi ndipo coefficient yake yowonjezera kutentha ndi yaikulu. Pakukonza zowotcha za silicon, makamaka pakupera kapena kupukuta kothamanga kwambiri, chifukwa cha kuwonongeka ndi kusinthika kwa matenthedwe a grinding disc, kusalala ndi kufanana kwa chotupa cha silicon ndizovuta kutsimikizira. Chimbale chogaya chopangidwa ndisilicon carbide ceramicsimakhala ndi mavalidwe ochepa chifukwa cha kuuma kwake kwakukulu, ndipo mphamvu yake yowonjezera kutentha imakhala yofanana ndi ya silicon wafers, kotero imatha kugwedezeka ndikupukutidwa pa liwiro lalikulu.
Kuphatikiza apo, zowotcha za silicon zikapangidwa, zimafunika kuthandizidwa ndi kutentha kwambiri ndipo nthawi zambiri zimatengedwa pogwiritsa ntchito zida za silicon carbide. Ndizosatentha komanso zosawononga. Mpweya wofanana ndi diamondi (DLC) ndi zokutira zina zitha kuyikidwa pamwamba kuti ziwongolere magwiridwe antchito, kuchepetsa kuwonongeka kwa zopindika, ndikuletsa kufalikira.
Komanso, monga woimira m'badwo wachitatu wide-bandgap semiconductor zipangizo, silikoni carbide single crystal zipangizo ali ndi katundu monga lalikulu bandgap m'lifupi (pafupifupi 3 nthawi Si), mkulu matenthedwe madutsidwe (pafupifupi 3.3 nthawi Si kapena 10 nthawi ya GaAs), kuchuluka kwa ma electron saturation migration (pafupifupi 2.5 nthawi za Si) ndi magetsi owonongeka kwambiri (pafupifupi 10 nthawi za Si kapena 5 nthawi za GaAs). Zida za SiC zimapanga zolakwika za zida zamtundu wa semiconductor muzogwiritsira ntchito ndipo pang'onopang'ono zikukhala gawo lalikulu lamagetsi opangira magetsi.
Kufunika kwa matenthedwe apamwamba a silicon carbide ceramics kwakula kwambiri
Ndikukula kosalekeza kwa sayansi ndi ukadaulo, kufunikira kwa kugwiritsa ntchito zoumba za silicon carbide m'munda wa semiconductor kwachulukirachulukira, ndipo matenthedwe apamwamba ndi chizindikiro chofunikira kwambiri pakugwiritsa ntchito zida zopangira semiconductor. Chifukwa chake, ndikofunikira kulimbikitsa kafukufuku wokhudzana ndi matenthedwe apamwamba a silicon carbide ceramics. Kuchepetsa kuchuluka kwa okosijeni wa lattice, kuwongolera kachulukidwe, ndikuwongolera momveka bwino kagawidwe ka gawo lachiwiri mu latisi ndi njira zazikulu zosinthira matenthedwe amafuta a silicon carbide ceramics.
Pakadali pano, m'dziko langa pali maphunziro ochepa okhudzana ndi matenthedwe apamwamba a silicon carbide ceramics m'dziko langa, ndipo pakadali kusiyana kwakukulu poyerekeza ndi dziko lapansi. Mayendedwe a kafukufuku wamtsogolo akuphatikiza:
● Limbikitsani ndondomeko yokonzekera kafukufuku wa silicon carbide ceramic powder. Kukonzekera kwapamwamba kwambiri, otsika-oksijeni silicon carbide ufa ndi maziko okonzekera matenthedwe apamwamba a silicon carbide ceramics;
● Limbikitsani masankhidwe a zithandizo za sintering ndi kafukufuku wokhudzana nawo;
● Limbikitsani kafukufuku ndi chitukuko cha zipangizo zapamwamba za sintering. Mwa kuwongolera njira yopangira sintering kuti mupeze microstructure yololera, ndikofunikira kupeza matenthedwe apamwamba a silicon carbide ceramics.
Njira zosinthira matenthedwe amafuta a silicon carbide ceramics
Chinsinsi chothandizira kutenthetsa kwamafuta a SiC ceramics ndikuchepetsa kufalikira kwa phonon ndikuwonjezera njira yaulere ya phonon. Kutentha kwa SiC kudzakhala bwino pochepetsa kuchulukana kwa porosity ndi malire a tirigu a SiC ceramics, kukonza kuyera kwa malire a tirigu a SiC, kuchepetsa zonyansa za SiC lattice kapena kuwonongeka kwa lattice, ndikuwonjezera chotengera chotengera kutentha mu SiC. Pakalipano, kukhathamiritsa mtundu ndi zomwe zili muzothandizira za sintering ndi chithandizo cha kutentha kwapamwamba kwambiri ndizo njira zazikulu zopititsira patsogolo kutentha kwazitsulo za SiC ceramics.
① Kukonza mtundu ndi zomwe zili muzothandizira zoyimbira
Zothandizira zosiyanasiyana za sintering nthawi zambiri zimawonjezedwa pokonzekera matenthedwe apamwamba a SiC ceramics. Pakati pawo, mtundu ndi zomwe zili muzothandizira za sintering zimakhudza kwambiri matenthedwe amtundu wa SiC ceramics. Mwachitsanzo, zinthu za Al kapena O mu Al2O3 system sintering aids zimasungunuka mosavuta mu lattice ya SiC, zomwe zimapangitsa kuti pakhale malo opanda ntchito ndi zolakwika, zomwe zimabweretsa kuwonjezeka kwafupipafupi kufalikira kwa phonon. Kuonjezera apo, ngati zomwe zili muzothandizira za sintering ndizochepa, zinthuzo zimakhala zovuta kuzimitsa ndi kuzimitsa, pamene zowonjezera zowonjezera zowonjezera zidzatsogolera kuwonjezeka kwa zonyansa ndi zolakwika. Zothandizira zamadzimadzi zochulukirapo zitha kulepheretsanso kukula kwa mbewu za SiC ndikuchepetsa njira yaulere yamaphononi. Choncho, pofuna kukonzekera mkulu matenthedwe matenthedwe ziwiya zadothi SiC, m'pofunika kuchepetsa zili sintering zothandizira mmene ndingathere pamene akwaniritsa zofunika za sintering kachulukidwe, ndi kuyesa kusankha sintering zothandizira kuti ndi zovuta kupasuka mu latisi SiC.
*Matenthedwe amtundu wa SiC ceramics pakawonjezeredwa zida zosiyanasiyana za sintering
Pakali pano, zotentha za SiC ceramics sintered ndi BeO ngati sintering aid ali ndi kutentha kwa chipinda-kutentha kwapamwamba (270W · m-1 · K-1). Komabe, BeO ndi zinthu zapoizoni kwambiri komanso carcinogenic, ndipo sizoyenera kugwiritsidwa ntchito mofala m'ma laboratories kapena m'mafakitale. Malo otsika kwambiri amtundu wa Y2O3-Al2O3 ndi 1760 ℃, chomwe ndi chithandizo chodziwika bwino chamadzimadzi pazitsulo za SiC. Komabe, popeza Al3 + imasungunuka mosavuta mu latisi ya SiC, pamene dongosololi limagwiritsidwa ntchito ngati chithandizo cha sintering, kutentha kwa chipinda cha chipinda cha SiC ceramics ndi osachepera 200W·m-1·K-1.
Zinthu zosawerengeka zapadziko lapansi monga Y, Sm, Sc, Gd ndi La sizisungunuka mosavuta mu lattice ya SiC ndipo zimakhala ndi kuyanjana kwakukulu kwa okosijeni, zomwe zimatha kuchepetsa mpweya wa SiC lattice. Choncho, Y2O3-RE2O3 (RE=Sm, Sc, Gd, La) dongosolo ndi wamba sintering aid pokonzekera mkulu matenthedwe conductivity (> 200W · m-1 · K-1) SiC ceramics. Kutenga Y2O3-Sc2O3 system sintering aid monga mwachitsanzo, mtengo wopatuka wa ion wa Y3 + ndi Si4 + ndi wawukulu, ndipo awiriwo samakumana ndi yankho lolimba. The solubility wa Sc mu koyera SiC pa 1800 ~ 2600 ℃ ndi yaing'ono, za (2~3) × 1017atomu ·cm-3.
② Chithandizo cha kutentha kwakukulu
Kutentha kwapamwamba kwa kutentha kwa SiC ceramics kumathandizira kuthetsa zolakwika za lattice, kusokonezeka ndi kupsinjika kotsalira, kulimbikitsa kusintha kwazinthu zina za amorphous kukhala makhiristo, ndikufooketsa mphamvu yakubalalika kwa phonon. Kuonjezera apo, kutentha kwa kutentha kwapamwamba kumatha kulimbikitsa kukula kwa mbewu za SiC, ndipo pamapeto pake kumapangitsanso kutentha kwa zinthuzo. Mwachitsanzo, pambuyo pa kutentha kwa kutentha kwambiri pa 1950 ° C, kutentha kwa kutentha kwa SiC ceramics kunawonjezeka kuchokera ku 83.03mm2 · s-1 mpaka 89.50mm2 · s-1, ndipo kutentha kwa chipinda-kutentha kunawonjezeka kuchokera ku 180.94W · m. -1·K-1 mpaka 192.17W·m-1·K-1. Chithandizo cha kutentha kwapamwamba kwambiri kumapangitsa kuti mphamvu ya deoxidation ya sintering aid pa SiC pamwamba ndi lattice, ndi kugwirizana pakati pa SiC njere kukhala wolimba. Pambuyo pa chithandizo cha kutentha kwambiri, kutentha kwa chipinda-kutentha kwa SiC ceramics kwasintha kwambiri.
Nthawi yotumiza: Oct-24-2024