Tsis ntev los no, kuv tau noj hmo nrog ib tug phooj ywg kawm ntawv qub uas ua haujlwm ntawm lub koom haum tshawb fawb txog cov khoom siv hauv aerospace. Peb tau tham txog lawv cov haujlwm tshiab, thiab nws hais rau kuv yam tsis paub meej tias, "Koj puas paub cov khoom siv tshiab twg uas peb xav paub tshaj plaws tam sim no? Tej zaum koj yuav tsis ntseeg - nws yog cov hmoov uas zoo li xuab zeb ntsuab zoo." Pom kuv lub ntsej muag xav tsis thoob, nws luag nyav thiab hais ntxiv tias, "Ntsuab silicon carbide micro-hmoov, koj puas tau hnov txog nws? Tej yam no yuav ua rau muaj kev hloov pauv me me hauv kev lag luam aerospace. " Yog hais qhov tseeb, kuv tsis ntseeg thaum xub thawj: cov khoom siv abrasive uas feem ntau siv rau hauv cov log sib tsoo thiab cov disc txiav yuav cuam tshuam li cas rau kev lag luam aerospace? Tab sis raws li nws piav qhia ntxiv, kuv paub tias muaj ntau yam ntxiv rau nws dua li kuv xav. Hnub no, cia peb tham txog qhov teeb meem no.
I. Kev Paub Txog "Cov Ntaub Ntawv Zoo" No
Cov silicon carbide ntsuab yog ib hom silicon carbide (SiC). Piv rau cov silicon carbide dub, nws muaj qhov huv dua thiab tsawg dua cov khoom tsis huv, yog li nws cov xim ntsuab sib txawv. Vim li cas nws thiaj li hu ua "micro-hmoov," nws hais txog nws cov khoom me me, feem ntau yog nruab nrab ntawm ob peb micrometers thiab kaum micrometers - kwv yees li ib feem kaum txog ib nrab ntawm txoj kab uas hla ntawm tib neeg cov plaub hau. "Tsis txhob cia nws siv tam sim no hauv kev lag luam abrasive dag koj," kuv tus phooj ywg hauv chav kawm hais tias, "nws muaj cov khoom zoo heev: qhov nyuaj siab, tiv taus kub siab, ruaj khov tshuaj lom neeg, thiab qhov coefficient qis ntawm thermal nthuav dav. Cov yam ntxwv no yog tsim los rau thaj chaw aerospace."
Tom qab ntawd, kuv tau ua qee qhov kev tshawb fawb thiab pom tias qhov no yog qhov tseeb. Qhov nyuaj ntawm Green silicon carbide yog qhov thib ob tsuas yog pob zeb diamond thiab cubic boron nitride; hauv huab cua, nws tuaj yeem tiv taus qhov kub siab ntawm ib puag ncig 1600 ° C yam tsis muaj oxidizing; thiab nws cov coefficient ntawm thermal expansion tsuas yog ib feem plaub mus rau ib feem peb ntawm cov hlau feem ntau. Cov lej no yuav zoo li qhuav me ntsis, tab sis nyob rau hauv thaj chaw aerospace, qhov twg cov khoom siv ua tau zoo yuav tsum nruj heev, txhua qhov parameter tuaj yeem coj tus nqi loj heev.
II. Kev Txo Qhov Hnyav: Kev Tshawb Nrhiav Mus Ib Txhis ntawm Lub Nkoj Mus Saum Ntuj
"Rau kev tsav dav hlau, kev txo qhov hnyav yeej ib txwm yog qhov tseem ceeb," ib qhokev tsav dav hlautus kws ua haujlwm hais rau kuv. "Txhua kilogram ntawm qhov hnyav uas txuag tau tuaj yeem txuag tau roj ntau lossis ua rau lub nra hnyav dua." Cov khoom siv hlau ib txwm muaj twb tau txog lawv qhov txwv hauv kev txo qhov hnyav, yog li txhua tus neeg lub siab tau tig mus rau cov khoom siv ceramic. Cov khoom siv ceramic matrix reinforced silicon carbide ntsuab yog ib qho ntawm cov neeg sib tw zoo tshaj plaws. Cov ntaub ntawv no feem ntau muaj qhov ceev ntawm tsuas yog 3.0-3.2 grams ib cubic centimeter, uas yog sib dua li hlau (7.8 grams ib cubic centimeter) thiab kuj muaj qhov zoo dua li titanium alloys (4.5 grams ib cubic centimeter). Qhov tseem ceeb, nws tswj tau lub zog txaus thaum txo qhov hnyav.
"Peb tab tom tshawb nrhiav kev siv cov khoom sib xyaw ua ke silicon carbide ntsuab rau cov cav," tus tsim qauv cav aerospace tau qhia. "Yog tias peb siv cov ntaub ntawv ib txwm muaj, cov khoom no yuav hnyav 200 kilograms, tab sis nrog cov khoom sib xyaw tshiab, nws tuaj yeem txo kom txog li 130 kilograms. Rau tag nrho lub cav, qhov kev txo qis 70-kilogram no yog qhov tseem ceeb." Zoo dua, qhov cuam tshuam txo qhov hnyav yog cascading. Cov khoom sib xyaw ua ke sib dua tso cai rau kev txo qhov hnyav sib xws hauv cov qauv txhawb nqa, zoo li qhov cuam tshuam domino. Cov kev tshawb fawb tau qhia tias hauv spacecraft, qhov txo qis 1-kilogram hauv qhov hnyav ntawm cov khoom siv tuaj yeem ua rau qhov txo qis 5-10 kilogram hauv qhov hnyav ntawm lub kaw lus.
III. Kev Tiv Thaiv Kub Siab: Tus "Stabilizer" hauv Cav
Qhov kub ua haujlwm ntawm cov cav aero yeej nce ntxiv tas li; cov cav turbofan siab heev tam sim no muaj qhov kub ntawm lub cav turbine ntau dua 1700 ° C. Ntawm qhov kub no, txawm tias ntau cov hlau kub siab pib ua tsis tiav. "Cov khoom kub ntawm lub cav tam sim no tab tom thawb cov kev txwv ntawm kev ua haujlwm ntawm cov khoom siv," kuv tus phooj ywg kawm ntawv los ntawm lub koom haum tshawb fawb hais. "Peb xav tau cov ntaub ntawv uas tuaj yeem ua haujlwm ruaj khov ntawm qhov kub siab dua." Cov khoom sib xyaw silicon carbide ntsuab tuaj yeem ua lub luag haujlwm tseem ceeb hauv thaj chaw no. Silicon carbide ntshiab tuaj yeem tiv taus qhov kub siab dua 2500 ° C hauv ib puag ncig inert, txawm hais tias hauv huab cua, oxidation txwv nws siv rau ib puag ncig 1600 ° C. Txawm li cas los xij, qhov no tseem siab dua 300-400 ° C dua li feem ntau cov hlau kub siab.
Qhov tseem ceeb tshaj, nws tseem muaj zog thaum kub siab. "Cov ntaub ntawv hlau 'mos' thaum kub siab, qhia txog kev nkag mus tob heev," piav qhia ib tug kws ua haujlwm kuaj cov ntaub ntawv. "Tab sis cov khoom sib xyaw silicon carbide tuaj yeem tswj tau ntau dua 70% ntawm lawv lub zog hauv chav tsev ntawm 1200 ° C, uas nyuaj heev rau cov ntaub ntawv hlau ua tiav." Tam sim no, qee lub tsev tshawb fawb tab tom sim sivsilicon carbide ntsuabcov khoom sib xyaw ua ke los tsim cov khoom tsis tig xws li cov vanes qhia nozzle thiab cov kab sib txuas hauv chav sib xyaw. Yog tias cov ntawv thov no tau ua tiav, lub zog thiab kev ua haujlwm ntawm cov cav yuav zoo dua ntxiv. IV. Kev Tswj Xyuas Kub: Ua Kom Kub "Mloog"
Cov tsheb thauj neeg caij dav hlau ntsib qhov chaw kub heev hauv qhov chaw: sab uas tig mus rau lub hnub tuaj yeem tshaj 100 ° C, thaum sab uas muaj duab ntxoov ntxoo tuaj yeem poob qis dua -100 ° C. Qhov sib txawv ntawm qhov kub thiab txias no ua rau muaj kev cov nyom loj rau cov khoom siv thiab cov khoom siv. Cov silicon carbide ntsuab muaj tus yam ntxwv zoo heev - kev ua kom sov zoo heev. Nws cov kev ua kom sov yog 1.5-3 npaug ntawm cov hlau ib txwm thiab ntau dua 10 npaug ntawm cov khoom siv ceramic ib txwm. Qhov no txhais tau tias nws tuaj yeem hloov pauv cua sov sai sai los ntawm thaj chaw kub mus rau thaj chaw txias, txo qhov kub hnyiab hauv zos. "Peb tab tom xav txog kev siv cov khoom sib xyaw silicon carbide ntsuab hauv cov kab ke tswj cua sov ntawm cov satellites," tus tsim qauv dav hlau hais tias, "piv txwv li, ua lub plhaub ntawm cov kav dej kub lossis ua cov khoom siv thermal conductive, kom ua rau qhov kub ntawm tag nrho lub cev sib xws dua."
Ntxiv mus, nws cov coefficient thermal expansion me heev, tsuas yog li 4 × 10⁻⁶ / ℃, uas yog li ib feem tsib ntawm cov txhuas alloy. Nws qhov loj me tseem yuav luag tsis hloov pauv nrog kev hloov pauv kub, ib qho yam ntxwv uas muaj txiaj ntsig zoo hauv cov tshuab kho qhov muag aerospace thiab cov tshuab antenna uas xav tau kev sib dhos meej. "Xav txog," tus tsim qauv tau muab ib qho piv txwv, "lub antenna loj ua haujlwm hauv orbit, nrog qhov kub sib txawv ntawm ntau pua degrees Celsius ntawm sab hnub thiab sab ntxoov ntxoo. Yog tias siv cov ntaub ntawv ib txwm muaj, kev nthuav dav thermal thiab kev cog lus yuav ua rau muaj kev hloov pauv ntawm cov qauv, cuam tshuam rau qhov tseeb ntawm qhov taw qhia. Yog tias siv cov ntaub ntawv sib xyaw ua ke ntsuab silicon carbide qis-nthuav dav, qhov teeb meem no tuaj yeem txo qis heev.
V. Kev Nyiag thiab Kev Tiv Thaiv: Ntau Tshaj Li "Kev Tiv Thaiv"
Cov tsheb thauj khoom niaj hnub no muaj kev thov ntau ntxiv rau kev ua haujlwm zais cia. Radar zais cia feem ntau yog ua tiav los ntawm kev tsim cov duab thiab cov khoom siv radar-absorbing, thiab ntsuab silicon carbide kuj muaj peev xwm tswj tau hauv thaj chaw no. "Pure silicon carbide yog ib qho semiconductor, thiab nws cov khoom hluav taws xob tuaj yeem hloov kho los ntawm doping," qhia tus kws tshaj lij cov ntaub ntawv ua haujlwm. "Peb tuaj yeem tsim cov khoom siv silicon carbide composite nrog kev tiv thaiv tshwj xeeb los nqus cov nthwv dej radar hauv qee qhov zaus." Txawm hais tias qhov no tseem nyob hauv theem tshawb fawb, qee lub chaw soj nstuam twb tau tsim cov qauv khoom siv silicon carbide-based composite nrog kev ua haujlwm zoo radar-absorbing hauv X-band (8-12 GHz).
Nyob rau hauv cov nqe lus ntawm qhov chaw tiv thaiv, qhov nyuaj ntawmsilicon carbide ntsuabkuj pom tseeb. Muaj ntau lub micrometeoroids thiab cov khib nyiab hauv qhov chaw. Txawm hais tias qhov hnyav ntawm txhua lub me me heev, lawv qhov ceev yog siab heev (txog li kaum kilometers ib ob), ua rau muaj zog cuam tshuam siab heev. "Peb cov kev sim qhia tau hais tias cov khoom siv silicon carbide ntsuab muaj 3-5 npaug ntawm kev tiv thaiv kev cuam tshuam ntawm cov khoom me me ceev piv rau cov hlau txhuas ntawm tib lub tuab," tus kws tshawb fawb tiv thaiv qhov chaw hais. "Yog tias siv rau hauv cov txheej tiv thaiv ntawm chaw nres tsheb lossis cov chaw soj ntsuam tob hauv qhov chaw yav tom ntej, nws tuaj yeem txhim kho kev nyab xeeb ntau heev."
Keeb kwm ntawm kev tsim kho dav hlau, hauv ib lub ntsiab lus, yog keeb kwm ntawm kev nce qib ntawm cov khoom siv. Txij li ntoo thiab ntaub canvas mus rau cov hlau txhuas, thiab tom qab ntawd mus rau cov hlau titanium thiab cov khoom sib xyaw, txhua qhov kev tsim kho tshiab ntawm cov khoom siv tau tsav kev dhia hauv kev ua tau zoo ntawm lub dav hlau. Tej zaum cov hmoov silicon carbide ntsuab thiab nws cov khoom sib xyaw yuav yog ib qho ntawm cov zog tseem ceeb rau kev dhia tom ntej. Cov kws tshawb fawb txog cov ntaub ntawv uas mob siab rau kev tshawb fawb hauv chaw soj nstuam thiab siv zog rau kev ua tau zoo hauv cov chaw tsim khoom yuav hloov pauv yav tom ntej ntawm lub ntuj. Thiab silicon carbide ntsuab, cov khoom siv zoo li qub no, yuav yog "hmoov khawv koob" hauv lawv txhais tes, pab tib neeg ya siab dua, deb dua, thiab muaj kev nyab xeeb dua.