Ososayensi bakha izinto ezikwazi ukumelana nokushisa kakhulu ezake zadalwa

Iqembu lososayensi abavela ku-NUST MISIS lenze i-ceramic material enezinga eliphezulu lokuncibilika phakathi kwezinhlanganisela ezaziwayo njengamanje.Ngenxa yenhlanganisela eyingqayizivele yezinto ezibonakalayo, ezomshini nezokushisa, izinto ezibonakalayo zithembisa ukusetshenziswa ezingxenyeni ezigcwele ukushisa zendiza, njengama-nose fairing, izinjini zejethi nemiphetho ebukhali yangaphambili yamaphiko asebenza emazingeni okushisa angaphezu kuka-2000 degrees C. Imiphumela ishicilelwe ku-Ceramics International.

Ama-ejensi amaningi ahamba phambili emkhathini (NASA, ESA, kanye nama-ejensi aseJapan,Chinakanye ne-India) benza ngenkuthalo izindiza-mkhathi ezisebenziseka kabusha, ezizonciphisa kakhulu izindleko zokuletha abantu nempahla emzileni, kanye nokunciphisa izikhawu zesikhathi phakathi kwezindiza.

“Okwamanje, imiphumela ebalulekile izuzwe ekuthuthukisweni kwalezi zinsimbi.Isibonelo, ukwehlisa irediyasi eyindingilizi yemiphetho ecijile yangaphambili yamaphiko iye kumasentimitha ambalwa kuholela ekwenyukeni okukhulu kokuphakama nokuhamba kahle, kanye nokunciphisa ukudonsa kwe-aerodynamic.Nokho, lapho uphuma emkhathini futhi ungena kuwo kabusha, phezu kwamaphiko endizamkhathi, amazinga okushisa angaba ngu-2000 degrees C angabonwa, afinyelele ku-4000 degrees C emaphethelweni impela.Ngakho-ke, uma kuziwa endizeni enjalo, kunombuzo ohlobene nokudalwa nokuthuthukiswa kwezinto ezintsha ezingasebenza emazingeni okushisa aphezulu kangaka, "kusho uDmitry Moskovskikh, inhloko ye-NUST MISIS Center for Constructional Ceramic Materials.

Phakathi nentuthuko yakamuva, inhloso yososayensi kwakuwukwakha into enephuzu elincibilikayo eliphakeme kakhulu kanye nezakhiwo eziphakeme zokusebenzisa imishini.I-triple hafnium-carbon-nitrogen system, i-hafnium carbonitride (Hf-CN), yakhethwa, njengoba ososayensi baseBrown University (US) babikezela ngaphambilini ukuthi i-hafnium carbonitride izoba nokuhamba okuphezulu okushisayo nokumelana ne-oxidation, kanye nokuncibilika okuphezulu kakhulu. iphuzu phakathi kwazo zonke izinhlanganisela ezaziwayo (cishe 4200 degrees C).

Besebenzisa indlela yokuzisakaza yokwakheka kokushisa okuphezulu, ososayensi be-NUSTMISIS bathola i-HfC0.5N0.35, (i-hafnium carbonitride) eduze nokwakheka kwethiyori, enobunzima obuphezulu be-21.3 GPa, obuphakeme kakhulu kunezinto ezintsha ezithembisayo, njenge-ZrB2/SiC (20.9 GPa) kanye ne-HfB2/SiC/TaSi2 (18.1 GPa).

“Kunzima ukukala indawo yokuncibilika kwento uma ingaphezu kuka-4000 degrees С.Ngakho-ke, sinqume ukuqhathanisa izinga lokushisa elincibilikayo lenhlanganisela ehlanganisiwe kanye nompetha wokuqala, i-hafnium carbide.Ukuze senze lokhu, sibeke amasampula e-HFC ne-HfCN acindezelwe epuleti le-graphite elimise okwe-dumbbell, futhi savala phezulu ngepuleti elifanayo ukuze sigweme ukulahlekelwa ukushisa, "kusho u-Veronika Buinevich, umfundi we-NUST MISIS post-graduate.

Okulandelayo, balixhuma ebhethrini besebenzisaama-electrode e-molybdenum.Zonke izivivinyo zenziwa ngokujulilevacuum.Njengoba i-cross-section yamapuleti e-graphite ihluke, izinga lokushisa eliphezulu lifinyelelwe engxenyeni encane kakhulu.Imiphumela yokushisisa kanyekanye kwezinto ezintsha, i-carbonitride, ne-hafnium carbide, ibonise ukuthi i-carbonitride inephuzu lokuncibilika eliphakeme kune-hafnium carbide.

Kodwa-ke, okwamanje, indawo ethile yokuncibilika yento entsha ingaphezu kuka-4000 degrees C, futhi ayikwazanga ukunqunywa ngokunembile elabhorethri.Ngokuzayo, ithimba lihlela ukwenza izivivinyo zokulinganisa izinga lokushisa elincibilikayo nge-pyrometry yezinga lokushisa eliphezulu lisebenzisa i-laser noma ukumelana nogesi.Bahlela futhi ukutadisha ukusebenza kwe-hafnium carbonitride ephumela ezimweni ze-hypersonic, okuzoba usizo ekusetshenzisweni okuqhubekayo embonini ye-aerospace.


Isikhathi sokuthumela: Jun-03-2020