Uhlolojikelele lwe-Boron Carbide Ceramics

2023-02-21

I-Boron Carbide (B4C) i-ceramic ehlala isikhathi eside eyakhiwe nge-Boron kanye ne-carbon. I-Boron Carbide ingenye yezinto eziqine kakhulu ezaziwa, ikleliswe endaweni yesithathu ngemuva kwe-cubic Boron nitride nedayimane. Kuyimpahla ehambisanayo esetshenziswa ezinhlelweni ezahlukahlukene ezibalulekile, kufaka phakathi izikhali zethangi, amavesti angangenwa izinhlamvu, kanye nezimpushana zokubhubhisa injini. Eqinisweni, iyinto ekhethwayo yezinhlelo zokusebenza ezihlukene zezimboni. Lesi sihloko sinikeza isifinyezo se-Boron Carbide kanye nezinzuzo zayo.

Iyini ngempela i-Boron Carbide?

I-Boron Carbide iyingxenye yamakhemikhali ebalulekile enesakhiwo sekristalu esivamile samabhoride asekelwe ku-icosahedral. I-compound yatholwa ngekhulu leshumi nesishiyagalolunye njenge-byproduct ye-metal boride reactions. Kwakwaziwa ukuthi inefomula yamakhemikhali kuze kube ngawo-1930, lapho ukwakheka kwayo kwamakhemikhali kulinganiselwa ukuthi yi-B4C. I-X-ray crystallography yento ibonisa ukuthi inesakhiwo esiyinkimbinkimbi esakhiwe womabili amaketanga e-C-B-C kanye ne-B12 icosahedra.

I-Boron Carbide inokuqina okwedlulele (9.5–9.75 esikalini se-Mohs), ukuzinza ngokumelene nemisebe ye-ionizing, ukumelana nokusabela kwamakhemikhali, nezici ezinhle kakhulu zokuvikela i-neutron. Ubulukhuni be-Vickers, i-elastic modulus, nokuqina kokuphuka kwe-Boron Carbide kucishe kufane naleyo yedayimane.

Ngenxa yokuqina kwayo okwedlulele, i-Boron Carbide iphinde ibizwa ngokuthi "idayimane elimnyama." Iphinde ikhonjiswe ukuthi inezindawo ze-semiconducting, ngezokuthutha zohlobo lwe-hopping ezibusa izakhiwo zayo ze-elekthronikhi. I-semiconductor yohlobo lwe-p. Ngenxa yokuqina kwayo okwedlulele, ithathwa njengento eqinile ye-ceramic engagugi, iyenze ifanele ukucubungula ezinye izinto eziqinile kakhulu. Ngaphezu kwezakhiwo zayo ezinhle zemishini kanye namandla adonsela phansi athile aphansi, ilungele ukwenza izembatho zempi ezingasindi.

Ukukhiqizwa kwe-Boron Carbide Ceramics

I-Boron Carbide powder ikhiqizwa ngokwentengiso ngokusebenzisa ukuhlanganisa (okubandakanya ukunciphisa i-Boron anhydride (B2O3) nge-carbon) noma ukusabela kwe-magnesiothermic (okubandakanya ukubangela i-Boron anhydride ukuthi isabele ne-magnesium lapho kukhona i-carbon black). Ekuphenduleni kokuqala, umkhiqizo wenza isigaxa esikhulu esimise okweqanda phakathi nendawo yesincibilikisi. Lokhu okumise okweqanda kuyakhishwa, kugaywe, bese kugaywa kusayizi ofanele okusanhlamvu ukuze kusetshenziswe okokugcina.

Esimeni sokusabela kwe-magnesiothermic, i-stoichiometric Carbide ene-granularity ephansi itholwa ngokuqondile, kodwa inokungcola, okuhlanganisa kufika ku-2% we-graphite. Ngenxa yokuthi iyinhlanganisela ye-inorganic ehlanganiswe ngokuhlanganyela, i-Boron Carbide kunzima ukuyicwilisa ngaphandle kokufaka ukushisa nokucindezela kanyekanye. Ngenxa yalokhu, i-Boron Carbide ivame ukwenziwa ibe yizimo eziminyene ngokucindezela ngokushisa izimpushana ezihlanzekile (2 m) emazingeni okushisa aphezulu (2100–2200 °C) endaweni engenalutho noma engenalutho.

Enye indlela yokukhiqiza i-Boron Carbide ukushisa okungenangcindezi ezingeni eliphezulu kakhulu lokushisa (2300–2400 °C), eliseduze nendawo yokuncibilika ye-Boron Carbide. Ukusiza ukwehlisa izinga lokushisa elidingekayo ukuze kube nokuminyana phakathi nale nqubo, izinsiza zokucwilisa ezifana ne-alumina, i-Cr, i-Co, i-Ni, nengilazi yengezwa kungxube yempushana.

Izicelo ze-Boron Carbide Ceramics

I-Boron Carbide inezinhlelo zokusebenza eziningi ezahlukene.

I-Boron Carbide isetshenziswa njenge-ejenti edlayo ne-abrasive.

I-Boron Carbide ekwifomu yempushana ifaneleka kahle ukuthi isetshenziswe njenge-abrasive ne-ejenti edlayo enenani eliphezulu lokususwa kwezinto lapho kusetshenzwa izinto eziqinile kakhulu.

I-Boron Carbide isetshenziselwa ukukhiqiza imibhobho ye-ceramic blasting.

I-Boron Carbide ayizweli kakhulu ukugqokwa, okuyenza ibe yinto enhle kakhulu yokuqhumisa imibhobho lapho icwiliswa. Noma isetshenziswa nezinto eziqhumisayo eziqine kakhulunjenge-corundum ne-silicon Carbide, amandla okuqhumisa ahlala efana, kukhona ukugqokwa okuncane, futhi imibhobho ihlala isikhathi eside.

I-Boron Carbide isetshenziswa njengento yokuvikela i-ballistic.

I-Boron Carbide ihlinzeka ngokuvikela okuqhathaniswayo kwe-ballistic naleyo yensimbi ye-armored ne-aluminium oxide kodwa ngesisindo esiphansi kakhulu. Imishini yezempi yesimanje ibonakala ngezinga eliphakeme lobulukhuni, amandla acindezelayo, kanye ne-modulus ephezulu yokunwebeka, ngaphezu kwesisindo esiphansi. I-Boron Carbide ingaphezu kwazo zonke ezinye izinto ezisetshenziswayo zalolu hlelo lokusebenza.

I-Boron Carbide isetshenziswa njenge-neutron absorber.

Kobunjiniyela, into ebaluleke kakhulu yokumunca i-neutron ngu-B10, esetshenziswa njenge-Boron Carbide ekulawuleni i-nuclear reactor.

Isakhiwo se-athomu se-boron siyenza isimunyisi se-neutron esisebenzayo. Ikakhulukazi, i-isotopu ye-10B, ekhona cishe ku-20% yobuningi bayo bemvelo, ine-nuclear cross-section ephezulu futhi ingathwebula ama-neutron ashisayo akhiqizwa ukusabela kwe-fission ye-uranium.

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