Kutshanje, nditye isidlo sangokuhlwa nomnye umfundi endifunda naye osebenza kwiziko lophando lwezinto zeenqwelo moya. Sithethe ngeeprojekthi zabo zamva nje, waza wandixelela ngokungaqondakaliyo wathi, “Uyazi ukuba zeziphi izinto ezintsha esinomdla kuzo ngoku? Usenokungakholwa – yiloo mgubo obonakala ngathi yisanti eluhlaza.” Ebona inkangeleko yam edidekileyo, wancuma waza wongeza wathi, “Umgubo omncinci we-silicon carbide eluhlaza, ngaba ukhe weva ngayo? Le nto isenokuba iza kubangela utshintsho oluncinci kwicandelo leenqwelo moya.” Ukuthetha inyani, ekuqaleni bendingaqinisekanga: loo nto irhabaxa esetyenziswa rhoqo ekugayeni amavili nasekusikeni iidiski inokunxulumana njani nomzi-mveliso weenqwelo moya ophucukileyo? Kodwa njengoko echaze ngakumbi, ndaqonda ukuba kukho okungaphezulu koko bendikucinga. Namhlanje, masithethe ngale ngongoma.
I. Ukwazi Le "Nto Ithembisayo"
I-silicon carbide eluhlaza ngokuyintloko luhlobo lwe-silicon carbide (SiC). Xa ithelekiswa ne-silicon carbide emnyama eqhelekileyo, inobunyulu obuphezulu kunye nokungcola okuncinci, yiyo loo nto inombala wayo oluhlaza okhanyayo. Ngokuphathelele isizathu sokuba "yi-micro-powder," ibhekisa kubukhulu bayo obuncinci kakhulu, ngokuqhelekileyo phakathi kwee-micrometer ezimbalwa kunye namashumi ee-micrometer - malunga nesinye kwishumi ukuya kwisiqingatha sobubanzi beenwele zomntu. "Musa ukuvumela ukusetyenziswa kwayo ngoku kwishishini lokurhawuzelela kukulahlekise," utshilo umfundi endifunda naye, "ineempawu ezintle kakhulu: ubunzima obuphezulu, ukumelana nobushushu obuphezulu, uzinzo lweekhemikhali, kunye nokwanda kobushushu obuphantsi. Ezi mpawu zenzelwe phantse intsimi yeenqwelo-moya."
Kamva, ndenze uphando kwaye ndafumanisa ukuba oku kuyinyani ngokwenene. Ubunzima be-silicon carbide bulandela idayimani kunye ne-cubic boron nitride; emoyeni, inokumelana namaqondo obushushu aphezulu amalunga ne-1600°C ngaphandle kwe-oxidizing; kwaye i-coefficient yayo yokwandiswa kobushushu yikota ukuya kwisithathu kuphela kuneyeentsimbi eziqhelekileyo. La manani anokubonakala omile kancinci, kodwa kwicandelo leenqwelo-moya, apho iimfuno zokusebenza kwezinto zingqongqo kakhulu, yonke iparameter inokuzisa ixabiso elikhulu.
II. Ukunciphisa Ubunzima: Ukusukela Inqwelo-moya Engunaphakade
“Kwinqwelo-moya, ukunciphisa ubunzima kusoloko kungundoqo,” aninqwelo-moyaInjineli indixelele. “Ikhilogram nganye yobunzima egciniweyo inokonga isixa esikhulu sepetroli okanye yonyuse umthwalo.” Izinto zesinyithi zemveli sele zifikelele kwimida yazo ngokwemiqathango yokunciphisa ubunzima, ngoko ke ingqalelo yomntu wonke iguqukele kwizinto zeseramikhi. Ii-composites ze-ceramic matrix eziqinisiweyo zesilicon carbide eziluhlaza zezinye zezona zinto zithembisayo. Ezi zinto zihlala zinobunzima obuyi-3.0-3.2 grams kuphela nge-cubic centimeter, obukhaphukhaphu kakhulu kunentsimbi (7.8 grams nge-cubic centimeter) kwaye zikwabonelela ngenzuzo ecacileyo ngaphezu kwe-titanium alloys (4.5 grams nge-cubic centimeter). Okubalulekileyo kukuba, igcina amandla aneleyo ngelixa inciphisa ubunzima.
“Siphanda ngokusetyenziswa kwee-composites ze-silicon carbide eziluhlaza kwiibhokisi zeenjini,” kwatsho umyili weenjini zeenqwelo moya. “Ukuba besisebenzisa izixhobo zemveli, eli candelo beliya kuba nobunzima obuziikhilogram ezingama-200, kodwa ngezinto ezintsha ezidityanisiweyo, lingancitshiswa liye kwiikhilogram ezili-130. Kwinjini yonke, olu nciphiso lweekhilogram ezingama-70 lubalulekile.” Okungcono nangakumbi, isiphumo sokunciphisa ubunzima siyancipha. Izinto ezidityanisiweyo zesakhiwo zivumela ukunciphisa ubunzima obuhambelanayo kwizakhiwo ezixhasayo, njengesiphumo se-domino. Izifundo zibonise ukuba kwi-spacecraft, ukunciphisa ubunzima beekhilogram ezi-1 kubunzima besakhiwo kunokukhokelela ekunciphiseni ubunzima be-5-10 yeekhilogram kwinqanaba lenkqubo.
III. Ukumelana nobushushu obuphezulu: "IsiQinisekiso" kwiinjini
Amaqondo obushushu okusebenza kweenjini ze-aero ayanda rhoqo; iinjini ze-turbofan eziphambili ngoku zinobushushu bokungena kwe-turbine obungaphezulu kwe-1700°C. Kolu bushushu, nee-alloys ezininzi zobushushu obuphezulu ziqala ukungasebenzi. “Iinxalenye ze-engine ezishushu okwangoku zityhala imida yokusebenza kwezinto,” utshilo umfundi endifunda naye kwiziko lophando. “Sifuna ngokungxamisekileyo izixhobo ezinokusebenza ngokuzinzileyo kumaqondo obushushu aphezulu nangakumbi.” Ii-composites ze-silicon carbide eziluhlaza zinokudlala indima ebalulekileyo kule ndawo. I-silicon carbide ecocekileyo inokumelana namaqondo obushushu angaphezu kwe-2500°C kwindawo engasebenziyo, nangona emoyeni, i-oxidation inciphisa ukusetyenziswa kwayo ukuya kuthi ga kwi-1600°C. Nangona kunjalo, oku kusengaphezulu kwe-300-400°C kunezinye ii-alloys zobushushu obuphezulu.
Okubaluleke ngakumbi, igcina amandla aphezulu xa kushushu kakhulu. “Izinto zesinyithi ‘zithambile’ xa kushushu kakhulu, zibonise ukuqhekeka okukhulu,” ucacise watsho unjineli ovavanya izinto. “Kodwa izinto ezidityanisiweyo zesilicon carbide zinokugcina amandla azo angaphezu kwama-70% kubushushu begumbi kwi-1200°C, nto leyo enzima kakhulu ukuba izinto zesinyithi ziyenze.” Okwangoku, amanye amaziko ophando azama ukusebenzisai-silicon carbide eluhlazaii-composites zokwenza izinto ezingajikeleziyo ezifana nee-nozzle guide vanes kunye nee-combustion chamber liners. Ukuba ezi zicelo ziphunyezwe ngempumelelo, i-thrust kunye nokusebenza kakuhle kweenjini kulindeleke ukuba kuphucuke ngakumbi. IV. Ulawulo lwe-Thermal: Ukwenza ubushushu "buthobele"
Izithuthi zeenqwelo-moya zijongene neendawo ezinobushushu obugqithisileyo esibhakabhakeni: icala elijonge elangeni lingadlula i-100°C, ngelixa icala elinomthunzi lingawela ngaphantsi kwe-100°C. Lo mahluko mkhulu wobushushu ubeka umngeni omkhulu kwizinto nakwizixhobo. I-carbon carbide eluhlaza inophawu olunqwenelekayo kakhulu—ukuqhuba ubushushu okugqwesileyo. Ukuqhuba kwayo ubushushu kuphindwe kayi-1.5-3 kuneentsimbi eziqhelekileyo kwaye kuphindwe kayi-10 kuneezixhobo eziqhelekileyo zeseramikhi. Oku kuthetha ukuba inokudlulisa ubushushu ngokukhawuleza ukusuka kwiindawo ezishushu ukuya kwiindawo ezibandayo, nto leyo enciphisa ubushushu obuphezulu kwindawo ethile. “Sicinga ukusebenzisa ii-composites ze-silicon carbide eluhlaza kwiinkqubo zolawulo lobushushu zeesathelayithi,” utshilo umyili weenqwelo-moya, “umzekelo, njengekhava yemibhobho yobushushu okanye njengee-substrates eziqhuba ubushushu, ukwenza ubushushu benkqubo yonke bufane ngakumbi.”
Ukongeza, i-coefficient yayo yokwandisa ubushushu incinci kakhulu, imalunga ne-4×10⁻⁶/℃ kuphela, emalunga nesinye kwisihlanu se-aluminium alloy. Ubungakanani bayo abutshintshi phantse ngenxa yotshintsho lobushushu, uphawu olubaluleke kakhulu kwiinkqubo ze-aerospace optical kunye neenkqubo ze-antenna ezifuna ulungelelwaniso oluchanekileyo. “Khawucinge,” umyili unike umzekelo, “i-antenna enkulu esebenza kwi-orbit, enomahluko wobushushu wamakhulu eedigri Celsius phakathi kwamacala ajonge elangeni nanombala. Ukuba kusetyenziswa izixhobo zemveli, ukwanda kobushushu kunye nokucutheka kunokubangela ukuguquka kwesakhiwo, okuchaphazela ukuchaneka kokukhomba. Ukuba kusetyenziswa izixhobo ezidityanisiweyo ze-silicon carbide eluhlaza okwanda kancinci, le ngxaki inokupheliswa kakhulu.”
V. Ukuzifihla Nokukhusela: Okungaphezulu Kokuba “Ukumelana” Nje
Iinqwelo-moya zanamhlanje zinemfuno ephezulu yokusebenza ngokufihlakeleyo. Ukufihlakeleyo kwe-radar kufezekiswa ikakhulu ngoyilo lwemilo kunye nezinto ezifunxa i-radar, kwaye i-silicon carbide eluhlaza ikwanamandla okulawula kule ndawo. “I-silicon carbide ecocekileyo yi-semiconductor, kwaye iipropati zayo zombane zinokulungiswa ngokusebenzisa i-doping,” yazisa ingcali yezinto ezisebenzayo. “Singayila izinto ezihlanganisiweyo ze-silicon carbide ezine-resistivity ethile ukuze zifunxe amaza e-radar ngaphakathi koluhlu oluthile lwefrikhwensi.” Nangona olu candelo lusesekwinqanaba lophando, ezinye iilabhoratri sele zivelise iisampulu zezinto ezihlanganisiweyo ezisekelwe kwi-silicon carbide ezinentsebenzo entle yokufunxa i-radar kwi-X-band (8-12 GHz).
Ngokuphathelele ukhuseleko lwendawo, inzuzo yobunzimai-silicon carbide eluhlazaKwakhona kuyabonakala. Kukho inani elikhulu lee-micrometeoroids kunye neenkunkuma zesithuba esibhakabhakeni. Nangona ubunzima bazo buncinci kakhulu, isantya sazo siphezulu kakhulu (ukuya kuthi ga kwishumi leekhilomitha ngomzuzwana), nto leyo ebangela amandla aphezulu kakhulu empembelelo. “Uvavanyo lwethu lubonisa ukuba izinto ezidityanisiweyo ze-silicon carbide eluhlaza zinamandla aphindwe kathathu ukuya kahlanu okumelana nempembelelo yesuntswana esantya esiphezulu xa kuthelekiswa nee-alloys ze-aluminium ezinobukhulu obufanayo,” utshilo umphandi wokhuseleko lwesithuba. “Ukuba zisetyenziswa kwiileya zokukhusela zezikhululo zesithuba okanye iiprobe zesithuba esinzulu kwixesha elizayo, zinokuphucula kakhulu ukhuseleko.”
Imbali yophuhliso lweenqwelo-moya, ngandlela ithile, yimbali yenkqubela phambili yezinto eziphathekayo. Ukusuka kwimithi kunye ne-canvas ukuya kwi-aluminium alloys, kwaye emva koko ukuya kwi-titanium alloys kunye nezinto ezidityanisiweyo, uyilo ngalunye lwezinto luye lwaqhuba inkqubela phambili ekusebenzeni kweenqwelo-moya. Mhlawumbi i-silicon carbide powder eluhlaza kunye nezinto zayo ezidityanisiweyo ziya kuba yenye yezona zinto zibalulekileyo eziqhuba inkqubela phambili. Ezo ngcali zezinto eziphanda ngenkuthalo kwiilabhoratri kwaye zilwela ukugqwesa kwiifektri zisenokutshintsha ikamva lesibhakabhaka ngokuthula. Kwaye i-silicon carbide eluhlaza, le nto ibonakala iqhelekile, isenokuba "ngumgubo womlingo" ezandleni zabo, inceda uluntu lubhabhele phezulu, kude, kwaye lukhuselekile.