1. IChemistry esisiseko kunye noyilo lweCrystallographic yeBoron Carbide
1.1 Ukubunjwa kweMolekyuli kunye nokuNxina koLwakhiwo
(Boron Carbide Ceramic)
I-Boron carbide (B EZINE C) ime njengenye yezona zinto zibangela umdla kwaye zibaluleke kakhulu kubuchwepheshe imathiriyeli yeseramikhi ngenxa yendibaniselwano eyodwa yokuqina okuqatha., ubukhulu obuphantsi, kunye nekhono elikhethekileyo lokufunxa ineutron.
Ngekhemikhali, yinto engeyiyo i-stoichiometric eyenziwe nge-boron kunye ne-athomu ye-carbon, ngefomula efanelekileyo ye-B ₄ C, nangona ukubunjwa kwayo okwenyani kunokwahluka ukusuka ku-B ₄ C ukuya ku-B ₁₀. IZIHLANU C, ebonisa uhlobo olukhulu lwe-homogeneity elawulwa ziinkqubo ezizezinye ngaphakathi kweleti yekristale entsonkothileyo.
Isakhelo se-crystal ye-boron carbide sivela kwinkqubo ye-rhombohedral (iqela lasemajukujukwini i-R3̄m), ichongwe ngothungelwano lwamacala amathathu e-12-atom icosahedra– ingqokelela yeeathom zebhoron– idityaniswe ngamatyathanga e-C-B-C okanye i-C-C ngokuthe ngqo kwi-axis ye-trigonal.
Ezi icosahedra, nganye iqulathe 11 iiathom zebhoron kunye 1 athom yekhabhoni (B ₁₁ C), badityaniswe ngokudibeneyo kunye neB eyomeleleyo ngokumangalisayo– B, B– C, kunye noC– C iibhondi, igalelo kumandla ayo omatshini anomtsalane kunye nokhuseleko lobushushu.
Ukubonakala kwezi yunithi ze-polyhedral kunye ne-interstitial chain kwazisa i-anisotropy yoyilo kunye neengxaki zangaphakathi., ezichaphazela zombini imikhwa yomatshini kunye nezindlu zedijithali zemveliso.
Ngokungafaniyo neeporcelains ezilula ezifana ne-alumina okanye i-silicon carbide, Uyilo lwe-atom ye-boron carbide ivumela ukuguquguquka okukhulu, ukwenza ukuba kwenzeke ukwakheka kwesiphene kunye nokujikeleza kweentlawulo ezichaphazela ukusebenza kwayo phantsi koxinzelelo kunye nokuxhalaba kunye ne-irradiation.
1.2 Iindawo zokuHlala zePhysical and Electronics ezivela kwi-Atomic Bonding
Uthungelwano lwe-covalent bonding kwi-boron carbide lukhokelela kwelinye lawona maxabiso aphakamileyo avunyiweyo obunzima phakathi kwemathiriyeli yokwenziwa.– okwesibini kuphela kwirubhi kunye ne-cubic boron nitride– ngokwesiqhelo ukusukela 30 ukuya 38 Inqaku eliphakathi kuluhlu lokuqina lweVickers.
Ubukhulu bayo buncitshiswe kakhulu (~ 2.52 g/cm ISITHANDATHU), ukuyijikeleza 30% Ikhaphukhaphu kune-alumina kwaye iphantse 70% Ikhaphukhaphu kunentsimbi, iadvanteji ebalulekileyo kwizinto ezinobuthathaka obufana nekhaka lomntu kunye neendawo ze-aerospace.
I-Boron carbide ibonisa ukungaphumeleli kweekhemikhali, ukumelana nogwayimbo luninzi lweeasidi kunye nee-antacids kwinqanaba lobushushu bendawo, nangona inokukhupha ngaphezulu 450 ° C emoyeni, ukudala i-boric oxide (B ₂ O AMATHANDATHU) kunye co2, enokuthi ibeke esichengeni ukunyaniseka kwesakhiwo kwiseto ze-oxidative zobushushu obuphezulu.
Ine-bandgap ebanzi (~ 2.1 eV), ukuyihlela njenge-semiconductor enezicelo ezinokuthi zibekho kubushushu obuphezulu be-elektroniki kunye nezixhobo zokujonga ukukhanya.
Ngaphaya koko, umlinganiso wayo ophezulu we-Seebeck kunye nokunciphisa ukuhanjiswa kwe-thermal kuyenza ibe ngumgqatswa wokuguqulwa kwamandla e-thermoelectric, ngakumbi kwiimeko ezinzima apho izinto zemveli zisilela.
(Boron Carbide Ceramic)
Imveliso ikwabonisa ukufunxwa kwe-neutron ephezulu ngenxa ye-neutron ephezulu yokubamba icandelo lomnqamlezo we-¹⁰ B isotope (malunga 3837 izisele zeeneutron ezishushu), ukuyinikezela kubalulekile kwiintonga zolawulo lwesixhobo senyukliya, ukukhusela, kunye neenkqubo zokugcina igesi etyaliweyo.
2. Ukudibanisa, Ukuphatha, kunye neMiqobo kuXinaniso
2.1 IiNdlela zokuVeliswa kweShishini kunye noKwakha uPowder
I-Boron carbide idalwe ubukhulu becala ngobushushu obuphezulu be-carbothermal yehla ye-boric acid (H ₃ BO ₃) okanye i-boron oxide (B ₂ O EZINHLANU) kunye nemithombo yekhabhoni efana nepetroleum coke okanye ilahle kwizifudumezi zombane ze-arc ezihamba ngaphezulu 2000 °C.
Impendulo iqhubeka njengoko: 2B ZIMBINI O ZIMBINI + 7C → B EZINE C + 6CO, ivelisa irhabaxa, Umgubo we-angular odinga ukungqusha kakhulu ukuze ufezekise ubungakanani beqhekeza le-submicron elilungele ukuphathwa kwe-ceramic.
Iindlela ezizezinye zokudityaniswa zibandakanya ukuzizalisa ubushushu obuphezulu (I-SHS), i-laser-induced chemical vapor deposition (CVD), kunye nobuchule bokuncedisa iplasma, ezisebenzisa ulawulo olungcono kwi-stoichiometry kunye ne-fragment morphology ukanti ayinabungozi kangako kusetyenziso lwemizi-mveliso.
Ngenxa yokuqina kwayo okuqatha, ukugaya i-boron carbide ngqo ibe ngumgubo omkhulu wonga amandla kwaye usesichengeni sokusulelwa yimithombo yeendaba, ukufuna ukusebenzisa i-boron carbide-lined mills okanye i-polymeric grinding aids ukugcina ubunyulu.
Iimpuphu ezibangelwayo kufuneka zichongwe ngononophelo kwaye zihlulwe ukuze kuqinisekiswe ukupakishwa okufanayo kunye nokuthenjwa kwe-sintering.
2.2 Imida yeSintering kunye neendlela eziPhambili eziDibeneyo
Ubunzima obubalulekileyo kulwakhiwo lweceramic ye-boron carbide bubume bayo obubambeneyo kunye ne-covalent self-diffusion coefficient., nto leyo enciphisa kakhulu uxinaniso ngexesha loxinzelelo olusemgangathweni olungenaxinzelelo.
Kwakhona kumaqondo obushushu asondelayo 2200 °C, i-sintering engenaxinzelelo ngokubanzi ivelisa iiporcelain ezinama-80– 90% yobunzima bezifundo, ukushiya i-porosity eshiyekileyo eyehlisa amandla omatshini kunye nokusebenza kwebhola.
Ukuloyisa oku, iindlela eziqhubekileyo zoxinaniso ezifana nokutyhala okushushu (HP) kunye nokutyhala okushushu kwe-isostatic (I-HIP) zisetyenziswa.
Ukutyhala okushushu kusebenza kuxinzelelo lwe-uniaxial (ngokuqhelekileyo 30– 50 MPa) kumaqondo obushushu phakathi 2100 ° C kunye 2300 °C, ukukhuthaza ukulungiswa kwakhona kweqhekeza kunye nokuguqulwa kweplastiki, ukuvumela ubukhulu bugqithise 95%.
I-HIP iphucula ngakumbi uxinaniso ngokusebenzisa uxinzelelo lwegesi ye-isostatic (100– 200 MPa) emva kwe-encapsulation, Ukuphelisa imingxunya evaliweyo kunye nokufumana ingxinano esondeleyo ngokuphucuka kokuqina kokuqhekeka.
Izongezo ezifana nekhabhoni, isilicon, okanye shift iibhoridi zentsimbi (umz., TiB ZIMBINI, I-CrB YESIBINI) ngamanye amaxesha ziyaziswa ngemilinganiselo emincinci ukunyusa ukuchuma kunye nokuthintela ukukhula okuziinkozo, nangona zinokuthi zinciphise kancinane ukuqina okanye ukufunxwa kakuhle kwe-neutron.
Ngaphandle kwezi nkqubela, Ubuthathaka bomda wokutya okuziinkozo kunye nobunkunka obungaphakathi buqhubekile bungumceli mngeni ongayekeleliyo, ngokukodwa phantsi kweemeko zokulayisha ezidlamkileyo.
3. Izenzo zoomatshini kunye nokuSebenza phantsi kweeMeko zokuLayisha ngokugqithisileyo
3.1 I-Ballistic Resistance kunye ne-Failing Systems
I-Boron carbide yamkelwa ngokubanzi njengeyona nto iphambili yokhuseleko lwebhola ekhaphukhaphu kwisikrweqe somzimba., ukufakwa kwemoto, kunye nokukhusela inqwelomoya.
Ukuqina kwayo okuphezulu kuyenza ukuba ibe mbi ngokufanelekileyo kwaye ijike iiprojekthi ezingenayo ezinjengeembumbulu zokugqobhoza kunye neziqwenga., Ukuphelisa amandla e-kinetic ngokusebenzisa iinkqubo ezibandakanya ukuqhekeka, microcracking, kunye nokutshintsha kweqonga lendawo.
Nangona kunjalo, iboron carbide ibonisa into ebizwa ngokuba yi-boron carbide “amorphization phantsi komothuko,” apho, phantsi kwempembelelo yesantya esiphezulu (ngokwesiqhelo > 1.8 km/s), ulwakhiwo lwekristale luqhekeka ngqo lube luphazamiseko, isigaba se-amorphous esingenawo amandla okuthwala umthwalo, okukhokelela kukusilela okulusizi.
Le amorphization eyenziwe ngoxinzelelo, ijongwe nge-in-situ ye-X-ray diffraction kunye nezifundo zeTEM, Ibangelwa kukuwohloka kweenkqubo ze-icosahedral kunye namatyathanga e-C-B-C phantsi koxinzelelo olukhulu lokucheba..
Iinzame zokuthomalalisa oku ziquka ukuphuculwa kweenkozo, isimbo esiyintlanganisela (umz., B EZINE C-SiC), kunye nommandla ongaphezulu ogqunywe ngeentsimbi ezithambileyo ukulibazisa ukwanda kokuqhekeka kunye nokuqhekeka.
3.2 Nxiba ukuchasana kunye nezicelo zoShishino
Ukuzikhusela kwangaphambili, Ukuxhathisa kwe-boron carbide kwenza ukuba kube yinto efanelekileyo kwizicelo zorhwebo ezibandakanya ukunxiba kakhulu, njengemilomo yokuqhunyiswa kwesanti, iingcebiso zokusika ijethi yamanzi, kunye nemidiya yokusila.
Ukuqina kwayo kodlula kakhulu i-tungsten carbide kunye ne-alumina, okukhokelela kubomi obude kunye nokunciphisa iindleko zokugcina kwi-atmosphere yemveliso ephezulu.
Izinto ezenziwe kwi-boron carbide zinokusebenza phantsi kwee-high-pressure abrasive flows ngaphandle kokutshatyalaliswa ngokukhawuleza, nangona kufuneka ukhathalelo lokuthintela ukothuka kwe-thermal kunye noxinzelelo lwe-tensile ngexesha lenkqubo.
Ukusetyenziswa kwayo kwiisetingi zenyukliya kufikelela kumacandelo angagugiyo kwiinkqubo zokuphatha igesi, apho ukuqina koomatshini kunye nokufunxwa kwe-neutron zifuneka zombini.
4. Ukusetyenziswa koBuchule kwiNyukliya, I-Aerospace, kunye neeTekhnoloji ezisakhulayo
4.1 Neutron Ukufunxa kunye nemitha Shielding Solutions
Phakathi kwesinye sezona zicelo zibalulekileyo ezingekho emkhosini ze-boron carbide zihlala kumandla e-athomu, apho isebenza njengemveliso efunxa ineutron kwiipali zolawulo, iipeliti zokuvala, kunye nezakhiwo zokukhusela kwimitha.
Ngenxa yobutyebi obuphezulu be-¹⁰ B isotope (ngokwesiqhelo ~ 20%, nangona kunjalo inokutyetyiswa ku > 90%), iboron carbide ibamba iineutron ezishushu ngendlela ¹⁰ B(n, a)ezisixhenxe Li impendulo, ukudala amaqhekeza e-alpha kunye ne-lithium ion equlethwe ngokulula ngaphakathi kwemveliso.
Le mpendulo ayiyo-radioactive kwaye ivelisa izinto ezincinci ezihlala ixesha elide, ukwenza i-boron carbide ikhuseleke kakhulu kwaye izinze ngakumbi kunezinye ezifana ne-cadmium okanye i-hafnium.
Isetyenziswa kwii activators zamanzi ezinoxinzelelo (PWRs), iireactors zamanzi abilayo (Ii-BWRs), kunye nabaphembeleli bophando, ngokwesiqhelo kwimo yeepellets ezisinisiweyo, iityhubhu ezinxibileyo, okanye iiphaneli ezidibeneyo.
Uzinzo lwayo phantsi kwe-neutron irradiation kunye nokukwazi ukugcina iimveliso ze-fission ziphucula ukhuseleko lwe-activator kunye nokhuseleko kunye nobomi obude bokusebenza..
4.2 I-Aerospace, Thermoelectrics, kunye neFuture Material Frontiers
Kwi-aerospace, I-boron carbide ifunyenwe ukuze isetyenziswe kumacala ahamba phambili emoto, apho into yayo ephezulu yokunyibilika (~ 2450 °C), ubukhulu obuncitshisiweyo, kunye nokumelana nokothuka kwe-thermal kunika iingenelo ngaphezulu kweealloyi zetsimbi.
Amandla ayo kwigajethi ye-thermoelectric ivela kwi-coefficient yayo ephezulu ye-Seebeck kunye nokuncipha kokusebenza kwe-thermal., ukwenza uguqulo oluthe ngqo lobushushu benkunkuma bube ngamandla ombane kwiatmosfera enzima efana ne-deep-space probes okanye iinkqubo ezinamandla zenyukliya..
Uphononongo lukwaqhuba ukuseka i-boron-carbide-based composites kunye ne-carbon nanotubes okanye igraphene ukuqinisa ukuqina kunye nokuhanjiswa kombane kwi-multifunctional architectural electronics..
Ngaphaya koko, Izakhiwo zayo zesemiconductor ziyaxhatshazwa kwiiyunithi zezivamvo zokusasazeka ngemitha kunye nezixhobo zokubona indawo kunye nezixhobo zenyukliya..
Kushwankathelo, I-boron carbide porcelains imele isiseko semathiriyeli kwindawo yokudityaniswa kobuchule obugqithisileyo boomatshini, uyilo lwenyukliya, kunye nemveliso eqhubela phambili.
Umxube wayo wohlobo olulodwa lokuqina okuphezulu, ubukhulu obuncitshisiweyo, kunye nesakhono sokufunxa i-neutron siyenza ingenakuthathelwa indawo kukhuselo kunye nobuchwepheshe benyukliya bale mihla, ngelixa uphando oluqhubekayo luhlala lusenza banzi amandla alo kwi-aerospace, ukuguqulwa kwamandla, kunye neekhompawundi zesizukulwana esilandelayo.
Njengoko iindlela zokusulungekisa zikhula kwaye uyilo olutsha oludibeneyo luvela, I-boron carbide ngokuqinisekileyo iya kuhlala kwinqanaba eliphambili lezinto ezintsha zokuyila eyona miqobo iyimfuneko yetekhnoloji..
5. Umthengisi
Advanced Ceramics yasekwa ngo-Oktobha 17, 2012, lishishini lobugcisa obuphezulu elizinikele kuphando nophuhliso, imveliso, ukuqhubekeka, ukuthengisa kunye neenkonzo zobugcisa bezixhobo ze-ceramic ezinxulumene neemveliso. Iimveliso zethu ziquka kodwa aziphelelanga kwiiMveliso zeCeramic zeBoron Carbide, IiMveliso zeCeramic zeBoron Nitride, Iimveliso zeCeramic zeSilicon Carbide, Iimveliso zeCeramic zeSilicon Nitride, IZirconium Dioxide yeeMveliso zeCeramic, njl. Ukuba unomdla, nceda uzive ukhululekile ukuqhagamshelana nathi.([email protected])
Iithegi: Boron Carbide, Boron Ceramic, Boron Carbide Ceramic
Onke amanqaku kunye nemifanekiso avela kwi-Intanethi. Ukuba kukho nayiphi na imiba ye-copyright, nceda uqhagamshelane nathi ngexesha lokucima.
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