1. Mehaho ea Sehlahisoa le Moralo o Tšebelisano
1.1 Litšobotsi tsa Bohareng tsa Maemo a Constituent
(Silicon nitride le silicon carbide composite ceramic)
Silicon nitride (Haeba ontong N ₄) le silicon carbide (SiC) ba tlamiloe ka bobeli ka kopanelo, li-porcelain tse se nang oxide li tumme ka ts'ebetso ea tsona e ikhethang mochesong o phahameng, senyang, le ho hloka litlhophiso ka mochini.
Silicon nitride e bonts'a ho tšoarella ho makatsang ha fracture, ho hanyetsa mocheso oa mocheso, le ho tsitsa ka lebaka la microstructure ea eona e ikhethang e entsoeng ka lithollo tse 'nè tsa β-Si tse tšeletseng tse nolofalletsang ho kheloha le mekhoa ea ho hokahanya..
E boloka ho tiea hoo e batlang e le 1400 ° C mme e na le coefficient ea katoloso e tlase ea mocheso (~ 3.2 × 10 ⁻⁶/ K), ho fokotsa tsitsipano ea mocheso nakong ea liphetoho tse potlakileng tsa mocheso.
Ka hlakoreng le leng, silicon carbide e sebelisa ho tiea ho hoholo, conductivity ea mocheso (hoo e ka bang 120– 150 W/(m · K )bakeng sa likristale tse le mong), khanyetso ea oxidation, le inertness ea lik'hemik'hale, e etsa hore e be ntle haholo bakeng sa lits'ebetso tsa ho lahla tse futhumetseng le tse futhumetseng.
Sekhahla sa eona se seholo (~ 3.3 eV bakeng sa 4H-SiC) ho phaella moo e fana ka tšireletso e ntle ea motlakase le mamello ea mahlaseli, e thusa maemong a nyutlelie le a semiconductor.
Ha e kenyelelitsoe ho motsoako, lisebelisoa tsena li bontša boitšoaro bo tšoanang: Si three N four e ntlafatsa ho tšoarella le ho senya khanyetso, ha SiC e ntlafatsa tsamaiso ea mocheso le ho sebelisa khanyetso.
Ceramic e hlahisoang ke mefuta e fapaneng e fumana tekano e ke keng ea finyelloa ke mohato ofe kapa ofe feela, ho theha sehlahisoa sa sebopeho se sebetsang hantle se etselitsoeng maemo a ts'ebeletso a feteletseng.
1.2 Setaele sa Motsoako le Boenjiniere ba Microstructural
Sebopeho sa Si six N ₄– Lik'hemik'hale tsa SiC li kenyelletsa taolo e nepahetseng holim'a potoloho ea sethala, morphology ea lijo-thollo, le tlamahano ea sefahleho ho holisa litlamorao tse sebelisanang.
Ka kakaretso, SiC e hlahisoa e le tšehetso e kholo ea likaroloana (ho tloha ho submicron ho ea ho 1 µm) ka har'a matrix a Si four N ₄, leha meaho e lekantsoeng hantle kapa e arohaneng le eona e fumanoa bakeng sa lits'ebetso tse ikhethileng.
Nakong ea sintering– hangata ka khase-khatello sintering (MOEKETSI KAKARETSO) kapa ho sututsa ka mofuthu– Li-bits tsa SiC li ama nucleation le kinetics ea nts'etsopele ea β-Si tse peli tsa N tse 'nè, e khothaletsang khafetsa libopeho tse nyane tse ntlafetseng le tse sa fetoheng.
Ntlafatso ena e ntlafatsa homogeneity ea mochini mme e fokotsa boholo ba sekoli, ho eketsa matla le botshepehi bo betere.
Ho lumellana ha sefahleho pakeng tsa mekhahlelo e 'meli ho bohlokoa; ka lebaka la hore ka bobeli ke li-porcelain tsa covalent tse nang le tekano e tšoanang ea crystallographic le boitšoaro ba nts'etsopele ea mocheso, ba theha meeli e hlophisehileng kapa e momahaneng e emang ho ts'oaroa ha lotho.
Li-additives tse kang yttria (Y ₂ O BORARO) le alumina (Ka bobeli O ₃) li sebelisoa e le thuso ea sintering ho bapatsa densification ea mokelikeli oa Si four N ₄ ntle le ho beha tšireletso ea SiC kotsing..
Leha ho le joalo, methati e mengata e eketsehileng e ka senya ts'ebetso ea mocheso o phahameng, kahoo sebopeho le ts'ebetso li hloka ho ntlafatsoa ho fokotsa lifilimi tsa moeli oa lijo-thollo tse benyang.
2. Maqheka a Ts'ebetso le Mathata a ho Densification
( Silicon nitride le silicon carbide composite ceramic)
2.1 Mosebetsi oa ho Lokisetsa Powder le Mekhoa ea ho Bopa
Sekolo se phahameng sa Si Two N ₄– Likarolo tsa SiC li qala ka ho kopanya homogeneous ea ultrafine, phofshoana tse hloekileng haholo tse sebedisang ho sila tse chitja tse metsi, attrition milling, kapa ho hasana ha ultrasonic mecheng ea litaba ea manyolo kapa ea metsi.
Ho finyella ho hasana ho tsitsitseng ho bohlokoa ho qoba sehlopha sa SiC, e ka sebetsang joalo ka li-concentrators tsa matšoenyeho le matla a tlase a ho robeha.
Li-binders le dispersants li kenyellelitsoe ho ts'ehetsa ho emisoa ha ho etsoa maqheka a kang slip casting, ho hasanya theipi, kapa ho bopa ka sethunya, ho itšetlehile ka ntho e lakatsehang geometry.
'Mele o motala ka mor'a moo o omisitsoe ka hloko ebe o tlosoa ho tlosa lintho tse phelang pele li sintering, mokgoa o hlokang sekgahla se laotsweng sa ho futhumala ha ntlo ho thibela ho petsoha kapa ho sosobana.
Bakeng sa tlhahiso ea sebopeho se haufi le marang-rang, Mekhoa ea tlatsetso joalo ka binder jetting kapa stereolithography ea hlaha, ho etsa hore ho khonehe bakeng sa li-geometri tse rarahaneng tseo pele li neng li ke ke tsa finyelloa ka ts'ebetso ea setso ea ceramic.
Mekhoa ena e hloka li-feedstocks tse ikhethileng tse nang le rheology e kholo le ho tiea ha tikoloho, hangata a kenyelletsa lipitsa tsa porcelain tse entsoeng ka polima kapa lisebelisoa tse utloang bohloko tse nang le liphofshoana tse kopaneng..
2.2 Lisebelisoa tsa Sintering le Stage Security
Khokahano ea Tšelela N NANE– Li-composite tsa SiC li thata ka lebaka la tlamahano e tiileng le ho itšehla thajana ha naetrojene le khabone maemong a mocheso a bohlokoa..
Mokelikeli-mokhahlelo oa sintering o sebelisa lefatše le sa tloaelehang kapa alkaline planet oxides (mohlala, Y PELI O TŠELELA, MgO) e fokotsa mocheso oa eutectic mme e ntlafatsa lipalangoang tse ngata ka ho qhibiliha ha silicate ea nakoana.
Tlas'a khatello ea khase (hangata 1– 10 MPa N ₂), ho qhibiliha hona ho thusa ho hlophisa bocha, tharollo-pula, le tšubuhlellano ea ho qetela ha e ntse e fokotsa ho arohana ha Si four N FOUR.
Ho ba teng ha SiC ho ama viscosity le ho koloba ha karolo ea mokelikeli, mohlomong ho fetola kholo ea lijo-thollo anisotropy le ponahalo ea ho qetela.
Liphekolo tsa ho futhumatsa ka mor'a ho sintering li ka 'na tsa amana le ho ba le maemo a tloaelehileng a amorphous meeling ea lijo-thollo., ho matlafatsa thepa ea mochini oa mocheso o phahameng le ho hanyetsa oxidation.
Phapang ea X-ray (XRD) le ho hlahloba microscope ea elektronike (TSEBANG) li sebelisoa khafetsa ho netefatsa bohloeki ba sethala, ho hloka methati ya bobedi e sa rateheng (mohlala, Ke ba babeli N PEDI O), le microstructure e tšoanang.
3. Sebetsa sa Mechine le Thermal Tlas'a Lotho
3.1 Stamina, Matla, le Ho Hanyetsa Mokhathala
Haeba Oven N ₄– Likarolo tsa SiC li bonts'a ts'ebetso e phahameng ea mochini ha e bapisoa le li-porcelain tsa monolithic, e nang le matla a ho fetofetoha a feteletseng 800 Litekanyetso tsa MPa le fracture sturdness li fihla ho 7– 9 MPa · m 1ST/ ².
Sephetho se matlafatsang sa likhechana tsa SiC se sitisa motsamao o sa tsitsang le ho ata ha fracture, ha lithollo tsa Si tse peli tsa N tse telele li ntse li fana ka matlafatso ka lisebelisoa tsa ho hula le ho hokahanya.
Mokhoa ona oa ho toughening habeli o etsa hore thepa e hanane le tshusumetso, paesekele e futhumetseng, le mokhathala oa mechine– ea bohlokoa bakeng sa likarolo tse potolohang le likarolo tsa sebopeho sebakeng sa sefofane le tsamaiso ea matla.
Creep resistance e lula e ikhetha 1300 °C, ka lebaka la botsitso ba marang-rang a covalent le ho fokotseha ha moeli oa lijo-thollo ha mekhahlelo ea amorphous e theoleloa..
Maemo a tiileng ka kakaretso a fapana ho tloha ho 16 ho 19 GPA, e fana ka ts'ebetso e ikhethang ea ho khathala le ho senyeha ha maemo libakeng tse hoholehang joalo ka potoloho e tletseng lehlabathe kapa mehala ea ho thella..
3.2 Tsamaiso ea Mocheso le Tšireletseho ea Tikoloho
Ho eketsoa ha SiC ho phahamisa haholo conductivity ea mocheso oa motsoako, kgafetsa e menahaneng habedi ya Si tsheletseng e hlwekileng NNE (ho tloha ho 15– 30 W/(m · K) )ho ea ho 40– 60 W/(m · K) ho ipapisitse le SiC web content le microstructure.
Matla ana a matla a ho fetisa mocheso a lumella hore ho be le tsamaiso e ngata e ka tšeptjoang ea mocheso likarolong tse senotsoeng ho futhumatsa sebakeng se matla, joalo ka liner tse tukang kapa likarolo tse shebaneng le plasma.
Motsoako o boloka ts'ireletso e lekantsoeng tlas'a likhahla tse phahameng tsa mocheso, ho ema ho fihlela spallation le fracturing ka lebaka la tsoelo-pele e tšoanang ea mocheso le parameter e phahameng ea mocheso oa mocheso. (R-boleng).
Ho hanyetsa oxidation ke monyetla o mong oa bohlokoa; SiC e etsa silika e sireletsang (SiO ₂) lera nakong ea ho pepesehela oksijene mochesong o phahameng, e leng eona e tiisang le ho feta le ho boloka litaba tse kaholimo.
Lera lena le sa sebetseng le sireletsa SiC le Si Three N ₄ (e eketsang oxidize ho SiO ₂ le N ₂), ho etsa bonnete ba nako e telele moeeng, mouoane o boima, kapa sepakapaka se tukang.
4. Likopo le Litsela tsa Bokamoso tsa Tekheniki
4.1 Sepakapaka, Matla, le Mekhoa ea Liindasteri
Ke Bapedi N NNE– Lik'hemik'hale tsa SiC li ntse li kenngoa butle-butle ho lijenereithara tsa khase tsa moloko o latelang, moo ba lumellang mocheso o phahameng oa ho sebetsa, matlafatsoa matla a mafura, le litlhoko tse fokolang tsa ho pholisa.
Lintho tse kang mahare a turbine ea moea, li-combustor liners, le li-vanes tse tataisang li-nozzle li fumana ho tsoa ho bokhoni ba sehlahisoa ba ho mamella ho palama libaesekele tse futhumatsang le ho roala mochini ntle le ho senyeha ho hoholo..
Limeleng tsa matla a athomo, haholo-holo li-reactors tse nang le mocheso o phahameng oa khase (HTGRs), likarolo tsena li sebetsa joalo ka litšepe tsa khase kapa litšehetso tsa meralo ka lebaka la ho hanyetsa mahlaseli a neutron le bokhoni ba ho boloka ntho ea fission..
Ka litlhophiso tsa indasteri, li sebelisoa ho sebetsana le tšepe e nang le metsi, thepa ea ka tlung ea sebōpi, le li-nozzles tse manganga le li-bearings, moo litšepe tse tloaelehileng li neng li tla haella kapele haholo.
Sebopeho sa bona sa boima bo bobebe (botenya ~ 3.2 g/cm BOHLANO) e boetse e ba etsa hore ba ipiletse bakeng sa propulsion ea sefofane le likarolo tsa koloi tsa hypersonic tse tlas'a mocheso o futhumatsang moea..
4.2 Tlhahiso e Tsoetseng Pele le Kopanyo ea Mesebetsi e Meholo
Boithuto bo hlahang bo tsepamisitse maikutlo ho nts'etsopele ea maemo a ts'ebetso a Six NNE– Mekhoa ea SiC, moo sebopeho se fapanang ka sebaka ho matlafatsa mocheso, mochine, kapa thepa ea bolulo ea electromagnetic ho pholletsa le ntho e le 'ngoe.
Sistimi ea mefuta e fapaneng e kenyelletsang CMC (motsoako oa matrix oa ceramic) meaho e nang le fiber reinforcement (mohlala, SiC_f/ SiC– Si Five N ₄) tobetsa meeli ea mamello ea tšenyo le khatello ea ho hloleha.
Tlhahiso e eketsehileng ea metsoako ena e lumella topology-optimized warmth exchangers, li-microreactors, le likanale tse nchafalitsoeng tsa moea tse nang le meaho ea ka hare ea latticework e ke keng ea finyelloa ka ho sebetsa ka machining.
Holim'a moo, meaho ea bona ea mantlha ea dielectric le ts'ireletso ea mocheso li ba etsa bakhethoa bakeng sa radome e pepeneneng ea radar le lifensetere tsa lehae tsa li-antenna li-platform tse lebelo le phahameng..
Ha litlhoko li ntse li hola bakeng sa lihlahisoa tse sebetsang ka mokhoa o ts'epahalang tlas'a meroalo e feteletseng ea thermomechanical, Haeba ontong N ₄– Lik'hemik'hale tsa SiC li emela tsoelo-pele e kholo ea boenjiniere ba ceramic, ho kopanya bokgabane le tshebetso ka bonngwe, sethala se tšoarellang.
Ha re phethela, silicon nitride– silicon carbide composite ceramics e bonts'a matla a thepa-ka-moralo, ho sebelisa matla a ho 2 li-porcelain tse ncha ho hlahisa tsamaiso e nyalisitsoeng e nang le bokhoni ba ho hōla libakeng tse matla ka ho fetisisa tse sebetsang.
Tsoelo-pele ea bona e tsoelang pele e tla phetha karolo ea bohlokoa pele ho nako ea matla a hloekileng, sefofane, le theknoloji ea sejoale-joale ea khoebo lekholong la bo21 la lilemo.
5. Morekisi
TRUNNANO ke morekisi oa Spherical Tungsten Powder e nang le over 12 lilemo tsa boiphihlelo ba ho boloka matla a nano-building le nts'etsopele ea nanotechnology. E amohela tefo ka Credit Card, T/T, West Union le Paypal. Trunnano e tla romella thepa ho bareki ba mose ho maoatle ka FedEx, DHL, ka moea, kapa ka lewatle. Haeba u batla ho tseba haholoanyane ka Spherical Tungsten Powder, ka kopo ikutloe u lokolohile ho ikopanya le rona le ho romela potso.
Li-tag: Silicon nitride le silicon carbide composite ceramic, Si3N4 le SiC, ceramic e tsoetseng pele
Lingoliloeng tsohle le litšoantšo li tsoa Marang-rang. Haeba ho na le litaba tsa copyright, ka kopo ikopanye le rona ka nako ho hlakola.
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