1. Chemistry ea Motheo le Moralo oa Crystallographic oa Boron Carbide
1.1 Sebopeho sa limolek'hule le ho rarahana ha sebopeho
(Ceramic ea Boron Carbide)
Boron carbide (B NNE C) e eme e le e 'ngoe ea lisebelisoa tsa ceramic tse khahlang ka ho fetesisa le tsa bohlokoa ka ho fetesisa tsa theknoloji ka lebaka la motsoako oa eona o ikhethang oa ho tiea ho matla., botenya bo tlase, le bokhoni bo ikhethang ba ho monya neutron.
Ka lik'hemik'hale, ke ntho e seng stoichiometric haholo-holo e entsoeng ka boron le liathomo tsa carbon, ka foromo e nepahetseng ea B ₄ C, leha sebopeho sa eona sa 'nete se ka fapana ho tloha ho B ₄ C ho ea ho B ₁₀. HLANO C, e bonahatsang mefuta e mengata e fapaneng ea homogeneity e laoloang ke mekhoa e meng ka har'a lesela la eona le rarahaneng la kristale.
Moralo oa kristale oa boron carbide o tsoa ho sistimi ea rhombohedral (sehlopha sa sebaka R3̄m), e khetholloa ka marang-rang a mararo a 12-atom icosahedra– pokello ea liathomo tsa boron– e hokahantsoeng ke liketane tse tobileng tsa C-B-C kapa C-C haufi le axis ea trigonal.
Li-icosahedra tsena, e ngoe le e ngoe e na le 11 liathomo tsa boron le 1 athomo ea carbon (B₁₁ C), li hokahane ka kopanelo le matla a makatsang a B– B, B– C, le C– C litlamo, ho kenya letsoho ho matla a eona a tsotehang a mochine le tšireletso ea mocheso.
Ponahalo ea likarolo tsena tsa polyhedral le liketane tsa interstitial li hlahisa mathata a meralo ea anisotropy le mathata a kahare., tse amang ka bobeli litloaelo tsa mochini le matlo a dijithale a sehlahisoa.
Ho fapana le li-porcelain tse bonolo tse kang alumina kapa silicon carbide, boron carbide's meralo ea athomo e lumella ho feto-fetoha ha maemo ho hoholo., ho etsa hore ho khonehe ho theha sekoli le phallo ea litefiso tse amang ts'ebetso ea eona tlas'a khatello ea maikutlo le matšoenyeho le mahlaseli.
1.2 Libaka tsa Bolulo tsa 'Mele le tsa Elektronike Tse Tsoang ho Tlamahanngoa ha Atomic
Khokahano e kopaneng ea boron carbide e lebisa ho boleng bo phahameng ka ho fetesisa bo hlokomelehang har'a thepa ea maiketsetso.– ea bobeli feela ho ruby le cubic boron nitride– hangata ho tloha ho 30 ho 38 Kakaretso ea lintlha tsa sehlopha ho Vickers e tiileng.
Botenya ba eona bo fokotsehile haholo (~ 2.52 g/cm tsheletseng), ho e etsa ho potoloha 30% e bobebe hofeta alumina mme e batlile 70% bobebe hofeta tshepe, molemo oa bohlokoa lits'ebetsong tse sa tsotelleng boima joalo ka thebe e le 'ngoe le likarolo tsa sepakapaka.
Boron carbide e bonts'a ho se sebetse hantle ha lik'hemik'hale, ho mamella ho otloa ke li-acid tse ngata le li-antacid maemong a mocheso oa sebaka, le hoja e ka oxidize ho feta 450 ° C moeeng, ho theha boric oxide (B ₂ O TŠELELA) le co2, e ka senyang botšepehi ba sebopeho maemong a mocheso o phahameng oa oxidative.
E na le lekhalo le pharaletseng (~ 2.1 eV), ho e arola e le semiconductor e nang le lits'ebetso tse ka bang teng ho lisebelisoa tsa elektronike tse nang le mocheso o phahameng oa mocheso le lisebelisoa tsa mahlaseli..
Ho feta moo, Coefficient ea eona e phahameng ea Seebeck le ho fokotsa mocheso oa mocheso ho etsa hore e be mokhethoa bakeng sa phetolo ea matla a thermoelectric., haholo-holo libakeng tse matla moo thepa ea setso e hlōlehang.
(Ceramic ea Boron Carbide)
Sehlahisoa se boetse se bonts'a ho monya ha neutron ho makatsang ka lebaka la ho ts'oaroa ha neutron e phahameng ea ¹⁰ B isotope. (ka 3837 meliko bakeng sa li-neutron tse chesang), ho e fana ka bohlokoa lithupeng tsa taolo ea matla a nyutlelie, sireletsang, le tsamaiso ea sebaka sa polokelo ea khase e tsetelitsoeng.
2. Synthesis, Ho tshoara, le Litšitiso ho Densification
2.1 Tlhahiso ea Liindasteri le Mekhoa ea Kaho ea Phofo
Boron carbide e entsoe haholo ka ho fokotseha ha mocheso o phahameng oa mocheso oa boric acid (H ₃ BO ₃) kapa boron oxide (B ₂ O BOHLANO) e nang le lisebelisoa tsa khabone joalo ka petroleum coke kapa mashala ka har'a lihitara tsa motlakase tse ntseng li feta 2000 °C.
Karabelo e tsoela pele joalo ka: 2B PELI O PEDI + 7C → B NNE C + 6CO, ho hlahisa mahoashe, li-angular powders tse hlokang ho siloa haholo ho fihlela boholo ba sekhechana sa submicron se loketseng ho sebetsana le ceramic..
Litsela tse ling tsa ho kopanya li kenyelletsa ho ipapisa le mocheso o phahameng oa mocheso (SHS), kemiso ea mouoane oa lik'hemik'hale o bakoang ke laser (CVD), le mekhoa e thusang plasma, tse sebelisang taolo e betere holim'a stoichiometry le fragment morphology empa ha li na kotsi haholo bakeng sa ts'ebeliso ea indasteri.
Ka lebaka la ho tiea ha eona ho matla, ho sila boron carbide ho etsa phofo e kholo ho nka matla 'me ho kotsing ea ho silafatsoa ke mecha ea litaba ea grating., ho batla ho sebelisa litsila tse nang le boron carbide kapa lithuso tsa ho sila tsa polymeric ho boloka bohloeki.
Li-powders tse hlahisoang li lokela ho khetholloa ka hloko le ho aroloa ho tiisa ho paka junifomo le sintering e ka tšeptjoang.
2.2 Meeli ea Sintering le Mekhoa e Tsoetseng Pele ea Motsoako
Bothata bo boholo kahong ea boron carbide ceramic ke sebopeho sa eona se kopanetsoeng se kopaneng le coefficient e tlase ea ho itšehla thajana., e fokotsang ho teteana haholo ka nako ya ho qoela ka sekgahla.
Hape ka mocheso o atamelang 2200 °C, sintering e se nang khatello hangata e hlahisa li-porcelain tse nang le 80– 90% ya botenya ba thuto, ho siea porosity e setseng e nyenyefatsang matla a mochini le ts'ebetso ea ballistic.
Ho hlola sena, mekhoa e tsoetseng pele ea ho teteana joalo ka ho sututsa ho chesang (HP) le ho sututsa ho chesang ha isostatic (HIP) li sebelisoa.
Ho sututsa ho chesang ho sebetsa khatello ea kelello ea uniaxial (hangata 30– 50 MPa) ka mocheso mahareng 2100 ° C le 2300 °C, ho khothaletsa tlhophiso ea likhechana le deformation ea polasetiki, ho dumella botenya bo fetelletseng 95%.
HIP e ntlafatsa le ho feta ka ho sebelisa khatello ea khase ea isostatic (100– 200 MPa) ka mor'a encapsulation, ho tlosa li-pores tse koetsoeng le ho fihlela boima bo haufi-ufi ka ho ntlafala ha crack.
Li-additives tse kang carbon, silicon, kapa li-borides tsa tšepe tse fetohang (mohlala, TiB MABELI, CrB MABELI) ka linako tse ling li hlahisoa ka bongata bo fokolang ho matlafatsa ho kopanya le ho sitisa kholo ea lijo-thollo, leha li ka fokotsa ho tiea kapa ho monya ha neutron hanyenyane.
Ho sa tsotellehe likhatelopele tsena, bofokoli ba moeli oa lijo-thollo le bofokoli ba ka hare e ntse e le liphephetso tse sa khaotseng, ka ho khetheha tlasa maemo a mahlahahlaha a ho kenya.
3. Liketso le Ts'ebetso ea Mechini Tlas'a Maemo a Ho Laola a Feteletseng
3.1 Ballistic Resistance le Ho hloleha Systems
Boron carbide e tsejoa haholo e le thepa ea pele bakeng sa tšireletso e bobebe ea ballistic lihlomong tsa 'mele., ho roala koloi, le tšireletso ea sefofane.
Ho tiea ha eona ho phahameng ho e thusa hore e senyehe hantle le ho khopamisa lintho tse kenang tse kang likulo le likotoana tse phunyang lihlomo., ho qhala matla a kinetic ka sistimi e nang le crack, microcracking, le phetoho ea sethala sa lehae.
Leha ho le joalo, boron carbide e bonts'a ketsahalo e bitsoang “amorphization tlas'a tsitsipano,” moo, tlasa tshusumetso ya lebelo le phahameng (hangata > 1.8 km/s), sebopeho sa kristale se robeha hantle hore se senyehe, mokhahlelo oa amorphous o se nang matla a ho jara, se bakang ho hloleha ho bohloko.
Amorphization ena e bakang khatello, e bonoa ka ho fapana ha X-ray le lithuto tsa TEM, e bakoa ke ho senyeha ha litsamaiso tsa icosahedral le liketane tsa C-B-C tlas'a khatello e feteletseng ea ho kuta..
Boiteko ba ho fokotsa sena ke ho ntlafatsa lijo-thollo, setaele se kopaneng (mohlala, B NNE C-SiC), le holim'a sebaka se koahetsoeng ka litšepe tse pliable ho liehisa ho ata ha fracture le ho arohana.
3.2 Apara Resistance le Lisebelisoa tsa Indasteri
Tšireletso e fetileng, boron carbide's abrasion resistance e etsa hore e be e loketseng bakeng sa likopo tsa khoebo tse kenyeletsang ho apara ka matla, joalo ka li-nozzles tsa sandblasting, malebela a ho seha jete ea metsi, le mecha ea phatlalatso ea ho sila.
Ho tiea ha eona ho feta ha tungsten carbide le alumina, e lebisang ho nako e telele ea bophelo le ho fokotsa litšenyehelo tsa tlhokomelo libakeng tse phahameng tsa tlhahiso ea lihlahisoa.
Lintho tse entsoeng ka boron carbide li ka sebetsa tlas'a khatello e matla ea abrasive phallo ntle le tšenyo e potlakileng, le hoja tlhokomelo e tlameha ho hlokoa ho thibela ho tšoha ha mocheso le khatello ea kelello nakong ea ts'ebetso.
Tšebeliso ea eona maemong a nyutlelie le eona e fihla ho likarolo tse sa sebetseng lits'ebetsong tsa ho sebetsana le khase, moo ho hlaka ha mochini le ho monya nyutrone ka bobeli li hlokahalang.
4. Likopo tsa Strategic in Nuclear, Sepakapaka, le Emerging Technologies
4.1 Neutron Absorption and Radiation Shielding Solutions
Among one of the most important non-military applications of boron carbide remains in atomic energy, where it serves as a neutron-absorbing product in control poles, closure pellets, and radiation shielding structures.
Due to the high wealth of the ¹⁰ B isotope (normally ~ 20%, however can be enriched to > 90%), boron carbide efficiently catches thermal neutrons via the ¹⁰ B(n, a)seven Li response, creating alpha fragments and lithium ions that are easily contained within the product.
This reaction is non-radioactive and generates very little long-lived byproducts, making boron carbide much safer and a lot more stable than alternatives like cadmium or hafnium.
It is made use of in pressurized water activators (PWRs), boiling water reactors (BWRs), le bahlohlelletsi ba lipatlisiso, hangata ka sebopeho sa sintered pellets, li-tubes tse apereng, kapa liphanele tse kopantsoeng.
Ho tsitsa ha eona tlas'a mahlaseli a neutron le bokhoni ba ho boloka lihlahisoa tsa fission ho ntlafatsa ts'ireletso ea activator le ts'ireletso le bophelo bo bolelele ba ts'ebetso..
4.2 Sepakapaka, Thermoelectrics, le Meeli ea Lintho Tsa Bokamoso
Sebakeng sa sefofane, boron carbide e ntse e sibolloa hore e sebelisoe mahlakoreng a ka pele a likoloi tsa hypersonic, moo ntlha ya yona e phahameng ya ho qhibidiha (~ 2450 °C), botenya bo fokotsehileng, le ho hanyetsa mocheso oa mocheso ho fana ka melemo ho feta li-alloys tsa tšepe.
Bokhoni ba eona ho lisebelisoa tsa thermoelectric bo tsoa ho coefficient ea eona e phahameng ea Seebeck le ho fokotsa mocheso oa mocheso., ho nolofalletsa phetoho e tobileng ea mocheso oa litšila hore e be matla a motlakase libakeng tse matla tse kang li-deep-space probes kapa lisebelisoa tsa nyutlelie..
Boithuto bo boetse bo ntse bo tsoela pele ho theha li-composites tse thehiloeng ho boron carbide tse nang le carbon nanotubes kapa graphene ho matlafatsa ho tiea le ho tsamaisa motlakase bakeng sa lisebelisoa tse ngata tsa elektroniki tsa meralo..
Ho feta moo, meaho ea eona ea semiconductor e ntse e sebelisoa ka lisebelisoa tsa kutlo tse thatafalitsoeng ke radiation bakeng sa ts'ebeliso ea sebaka le nyutlelie..
Ka kakaretso, li-porcelain tsa boron carbide li emela lisebelisoa tsa motheo mateanong a ts'ebetso e feteletseng ea mochini, moralo oa nyutlelie, le tlhahiso e tsoetseng pele.
Motsoako oa eona oa mofuta o le mong oa ho tiea ho hoholo, botenya bo fokotsehileng, le bokgoni ba ho monya nyutrone bo e etsa hore e se ke ya nkelwa sebaka ho tsa tshireletso le dithekenoloji tsa sejwalejwale tsa nyutlelie, athe boithuto bo tsoelang pele bo ntse bo tsoela pele ho atolosa matla a eona sebakeng sa sefofane, phetoho ea matla, le metsoako ea moloko o latelang.
Ha maano a ho hloekisa a ntse a eketseha, 'me ho hlaha meralo e mecha e kopaneng, boron carbide ka sebele e tla lula e le sehlohlolong se ka pele sa tlhahiso ea thepa bakeng sa litšitiso tse hlokahalang haholo tsa theknoloji..
5. Morekisi
Advanced Ceramics e thehiloe ka Mphalane 17, 2012, ke khoebo ea theknoloji e phahameng e ikemiselitseng ho etsa lipatlisiso le nts'etsopele, tlhahiso, ho sebetsa, thekiso le lits'ebeletso tsa tekheniki tsa lisebelisoa le lihlahisoa tse amanang le ceramic. Lihlahisoa tsa rona li kenyelletsa empa ha li felle feela ho Lihlahisoa tsa Ceramic tsa Boron Carbide, Lihlahisoa tsa Ceramic tsa Boron Nitride, Silicon Carbide Lihlahisoa tsa Ceramic, Silicon Nitride Lihlahisoa tsa Ceramic, Lihlahisoa tsa Ceramic tsa Zirconium Dioxide, etc. Haeba u thahasella, ka kopo ikutloe u lokolohile ho ikopanya le rona.([email protected])
Li-tag: Boron Carbide, Boron Ceramic, Ceramic ea Boron Carbide
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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