U-Old Zhang wachitha lonke ixesha lakhe lomsebenzi kwi-Aerospace Materials Institute. Ngaphambi kokuba athathe umhlala-phantsi, into awayeyithanda kakhulu yayikukuthatha abafundi bakhe baye kwindawo yokugcina izinto ukuze bafumane izinto. Wakhulula ibhakede yeplastiki emhlophe engenazintloni, wathabatha icephe lomgubo omhlophe ocolekileyo, okhrim ngecephe lokuvavanya, waza waliphosa kancinci phantsi kokukhanya. Uthuli lwahlala kancinci kancinci kumtha wokukhanya, lukhazimla kancinci. “Musa ukuyithatha lula le mpuphu emhlophe,” utshilo u-Old Zhang, ejonge ngamehlo akhe. “Ukuba iinqwelomoya kunye neerokethi esizakhayo zinokumelana nezinto ezisesibhakabhakeni ngamanye amaxesha kuxhomekeke kubuchule bale ‘mpuphu.’”
“Umgubo omhlophe” awayethetha ngawo yayinguumgubo we-alumina. Ivakala iqhelekile—ayicocwanga nje nge-bauxite? Kodwa umgubo we-alumina osetyenziswa kwi-aerospace wahlukile ngokupheleleyo kwi-alumina eqhelekileyo yomgangatho wezimboni. Ubunyulu bayo buphantse bube zii-nines ezine emva kwenqaku ledesimali; ubungakanani bayo besuntswana bulinganiswa ngee-nanometers kunye nee-micrometers; imo yayo—nokuba zii-spheres, ii-flakes, okanye iinaliti—zonke ziqwalaselwe ngononophelo. Ngamazwi kaLao Zhang, “Oku kukutya okumnandi ‘okongeza i-calcium’ kwizixhobo ezinzima zesizwe.”
Ngokuphathelele oko oku kunokwenziwa yile nto kwicandelo leenqwelo-moya, kukho izicelo ezininzi. Masiqale ngeyona "inzima"—ukunika iinqwelo-moya "isikrweqe." Ziziphi izinto ezoyikisayo kakhulu kuyo nayiphi na into ebhabha esibhakabhakeni, nokuba yinqwelo-moya eqhelekileyo okanye inqwelo-moya yokulwa? Amaqondo obushushu aphezulu kakhulu kunye nokuguguleka. Iiblade ze-turbine yenjini zijikeleza ngesantya esiphezulu kwiigesi zokukhupha umoya kumawaka eedigri zeCelsius; iintsimbi eziqhelekileyo bezinokuthamba kwaye zinyibilike kudala. Yintoni ekufuneka yenziwe? Iinjineli zeza nesisombululo esibalaseleyo: ukugquma umphezulu weblade ngengubo ekhethekileyo yeseramikhi. Izinto eziphambili zokwakha zale ngubo zihlala ziyi-alumina powder.
Kutheni uyikhetha? Okokuqala, ayitshisi ubushushu, inendawo yokunyibilika edlula ama-2000 degrees Celsius, nto leyo eyenza ibe “yisuti yokukhusela ubushushu” egqwesileyo. Okwesibini, iqinile kwaye ayigugi, ikhusela iiblayidi ekukhukulisekeni kwamasuntswana othuli ekuhambeni komoya ngesantya esiphezulu. Okungcono nangakumbi, ngokulungelelanisa ubungakanani beesuntswana zomgubo we-alumina kunye nokongeza ezinye izinto, i-porosity, ukuqina, kunye nokunamathela kwi-substrate yesinyithi yomgubo kunokulawulwa. Njengoko umsebenzi we-workshop onamava ekubeka ngokuhlekisa, “Kufana nokufaka umaleko we-sunscreen ye-ceramic ephezulu kwiiblayidi ze-turbine—ikhusela ilanga kwaye ayikrweli.” Ibaluleke kangakanani le “sunscreen”? Ivumela iiblayidi ze-turbine ukuba zisebenze kumaqondo obushushu aphezulu, kwaye kwi-degree nganye yeshumi ubushushu benjini buyanda, ukutyhala kuyanda kakhulu, ngelixa ukusetyenziswa kwepetroli kuncipha. Kwinqwelo-moya ezibhabha amashumi amawaka eekhilomitha, ukonga ipetroli kunye nokuphuculwa kokusebenza kuyinto enkulu. Ukuba ubushushu bokugquma luyi “sicelo sangaphandle,” ngoko ke indima yomgubo we-alumina kwizixhobo ezidityanisiweyo “sisincedisi sangaphakathi.”
Iinqwelo-moya zanamhlanje, iisathelayithi, kunye neerokethi zisebenzisa kakhulu izinto ezidityanisiweyo ukunciphisa ubunzima. Nangona kunjalo, ezi zixhobo ezidityanisiweyo ezisekelwe kwi-resin zinobuthathaka—azigugi, azichaphazeleki kubushushu obuphezulu, kwaye azinabo ubulukhuni obaneleyo. Izazinzulu zezinto ezikrelekrele zifake umgubo we-alumina, ingakumbi ubungakanani obuncinci.umgubo we-alumina, ngokulinganayo kwi-resin, njengentlama yokuxova. Oku kuhlanganiswa kunemiphumo ephawulekayo: ubulukhuni bento, ukumelana nokuguguleka, ukumelana nobushushu, kunye nokuzinza kobukhulu bonke kuyaphucuka kakhulu.
Umzekelo, imigangatho yekhabhini yeenqwelo-moya, izinto ezithile zangaphakathi, kwanezinye iindawo zesakhiwo ezingathwali mthwalo zisebenzisa le nto idityanisiweyo eqiniswe yi-alumina. Oku akuzenzi nje kuphela ukuba zibe lula kwaye zomelele kodwa kukwaphucula ukhuseleko, nto leyo ephucula kakhulu ukhuseleko. Isixhobo esichanekileyo esixhasa iisathelayithi, ezifuna utshintsho oluncinci lobukhulu phantsi kwemijikelo yobushushu obugqithisileyo, sikwaxhomekeke kakhulu kule nto. Kufana "nokufaka" umqolo kwiplastiki eguquguqukayo, okwenza kube namandla kunye nokuguquguquka.
Umgubo we-alumina ukwanayo "nesakhono esifihliweyo," esibalulekileyo kwicandelo leenqwelo-moya—sisigqubuthelo esihle kakhulu sokukhusela ubushushu kunye nezinto ezimelana nokukhupha umoya.
Xa isiphekepheke siphinda singene emoyeni sisuka esibhakabhakeni, kufana nokuwela kwisithando seplasma esingamawaka eedigri. Iqokobhe langaphandle le-capsule yokungena kwakhona kufuneka libe nomaleko omelana nobushushu "ozincamayo ukuze kubekho okulungileyo okukhulu." Umgubo we-alumina udlala indima ebalulekileyo ekwakhiweni kwezinto ezininzi ezimelana nobushushu. Xa udityaniswe nezinye izinto, wenza umaleko we-ceramic oqinileyo, onemingxuma, nokhusela kakhulu kumphezulu. Olu maleko luvutha kancinci kumaqondo obushushu aphezulu, luthwala ubushushu kwaye lugcina ubushushu bekhabini ngaphakathi koluhlu lokusinda lwee-astronauts ngokusebenzisa ukusetyenziswa kwalo. "Ngalo lonke ixesha ndibona i-capsule ebuyayo ifika ngempumelelo, kwaye umaleko wangaphandle wezinto ezimelana nobushushu umnyama otshisiweyo, ndicinga ngezo fomyula ezisekelwe kwi-alumina esizicoca ngokuphindaphindiweyo," watsho injineli ephezulu ephethe izinto ezimelana nobushushu. "Yatsha, kodwa umsebenzi wayo wafezwa ngokugqibeleleyo."
Ngaphandle kwezi zicelo ze-hardcore "eziphambili",umgubo we-aluminaibaluleke ngokulinganayo “ngasemva kwemiboniso.” Umzekelo, ekwenzeni izinto ezichanekileyo zeenqwelo-moya kunye neerokethi, ii-alloys ezininzi ezinamandla aphezulu kufuneka zitshiswe. Ngexesha lokutshiswe, iindawo ze-powder metallurgy kufuneka zixhaswe kwisithando sobushushu obuphezulu kusetyenziswa “ii-shims” ezithile okanye “iipleyiti zokudubula.” Ezi pleyiti kufuneka zingabi nabushushu, zingaguquguquki, kwaye zinganamatheli kwimveliso. Iipleyiti zokudubula ezenziwe nge-alumina ceramic ecocekileyo kakhulu ziba lolona khetho lufanelekileyo. Ngaphezu koko, kwiinkqubo zokugaya nokupolisha ezinye iindawo ezichanekileyo kakhulu, i-alumina micropowder ecocekileyo kakhulu yindlela yokupolisha ekhuselekileyo nesebenzayo.
Kakade ke, izinto ezixabisekileyo ngolo hlobo azinakusetyenziswa ngokungakhathali. Ngaba ubunyulu banele? Ngaba ukusasazwa kobungakanani beesuntswana kuyafana? Ngaba kukho ukuhlanganiswa kwezinto? Ngaba ukusasazeka kulungile? Yonke inkomba ichaphazela ukusebenza kwemveliso yokugqibela. Kwintsimi yeenqwelo-moya, nokuba yimpazamo encinci inokukhokelela kwimiphumo emibi. Ke ngoko, ukusuka ekukhethweni kwezinto eziluhlaza kunye nokuguqulwa kokucubungula ukuya kwiindlela zokusetyenziswa, inyathelo ngalinye lixhomekeke kwimigangatho yolawulo enzima, phantse enzima.
Umi kwindawo yokudibanisa iinqwelo-moya yanamhlanje, ujonge i-fuselage ekhazimlayo phantsi kwezibane, uyaqonda ukuba le nkqubo intsonkothileyo ebhabha esibhakabhakeni yimiphumo yezinto ezininzi ezibonakala ziqhelekile ezifana nomgubo we-alumina, nganye idlala indima yayo ngokupheleleyo. Ayilo lwakhiwo oluphambili, kodwa iyayomeleza isakhiwo; ayiniki amandla amakhulu, kodwa ikhusela umongo wenkqubo yokuqhubeleka; ayichazi ngqo indlela eya kuyo, kodwa iqinisekisa ukhuseleko lokubhabha.
Ukususela kwiingubo ezimelana nobushushu obuphezulu ukuya kwizinto ezidityanisiweyo eziqinisiweyo, kwaneengqimba ezizincamayo ezimelana nobushushu, ukusetyenziswaumgubo we-aluminaKwintsimi yeenqwelo-moya iyaqhubeka isiba nzulu ukuya kwindawo ekhaphukhaphu, enamandla, kwaye imelana ngakumbi neemeko ezingaqhelekanga. Kwixesha elizayo, ngokuphuhliswa kwezinto ze-alumina ezinobunyulu obuphezulu kunye neendlela ezikhethekileyo (ezifana nee-nanowires kunye nee-nanosheets), inokudlala indima engalindelekanga kulawulo lobushushu, ukusasazwa kobushushu bezixhobo ze-elektroniki, kwanokuveliswa kwendawo esithubeni.
Lo mgubo umhlophe, ongathethiyo nozinzileyo, unamandla amakhulu axhasa ukuphonononga kwabantu amazulu. Usikhumbuza ukuba kuhambo oluya ezinkwenkwezini, asidingi nje kuphela imibono emikhulu namandla anyukayo, kodwa kwanala “maphiko angabonakaliyo” athuleyo nazinzileyo aphucula ukusebenza kwezinto ezisisiseko. Ngexesha elizayo xa ujonga inqwelo moya ebhabha phezulu okanye ubukele umboniso omhle wokudubula kwerokethi, ungakhumbula ukuba ngaphakathi kwelo qela lesinyithi kunye nezinto ezidityanisiweyo, kukho “umoya omhlophe” onjalo, okhusela ukhuseleko kunye nobuhle bendiza nganye.