Plaub yam uas txiav txim siab xaiv cov alloy
Lub airframe aluminium alloy yeej tsis xaiv ntawm lub zog tensile ib leeg. Kev xaiv yog tsim los tiv thaiv plaub yam kev sib cuam tshuam: lub zog zoo li qub rau qhov txwv thiab qhov kawg ntawm kev thauj khoom, kev puas tsuaj rau lub zog seem nrog kev xav tias tawg, qaug zog tawg tus nqi rau kev soj ntsuam lub sijhawm, thiab kev tiv thaiv corrosion rau qhov chaw pabcuam. Ib qib uas yeej ntawm lub zog tuaj yeem poob ntawm qhov hnyav, uas yog vim li cas qhov siab -lub zog 7xxx tempers siv rau ntawm qhov chaw nro tis yeej tsis yog cov uas siv rau ntawm cov tawv nqaij hnyav heev.
Alloy Tsev Neeg thiab qhov twg lawv siv
| Alloy thiab tempered | Hom tensile ntau yam (MPa) | Hom 0.2% pov thawj ntau yam (MPa) | Tej daim ntawv thov |
|---|---|---|---|
| 2024-T3 daim ntawv | 440-470 Nws | 290-325 Nws | fuselage daim tawv nqaij, qis tis tawv nqaij |
| 2024-T351 phaj | 440-470 Nws | 290-325 Nws | Machined thav duab thiab tav |
| 7075-T6 phaj | 540-572 Ib | 470-503 Ib | Upper tis daim tawv nqaij, spar caps |
| 7075-T73 / T7351 | 470-505 Ib | 400-435 Nws | Qhov chaw raug kev nyuaj siab nyob rau hauv chloride |
| 7050-T7451 phaj | 510-540 Nws | 440-470 Nws | Thick machined bulkheads |
| Al-Li 2099-T83 extrusion | tsim cov ntaub ntawv rau ib phau ntawv pom zoo | tsim cov ntaub ntawv rau ib phau ntawv pom zoo | Nyhav-cov tawv nqaij tseem ceeb |
Cov ntau yam saum toj no yog cov phau ntawv qhia qhov tseem ceeb uas ib txwm hais rau nyias daim ntawv thiab phaj nyob rau hauv luv luv transverse kev taw qhia yog ignored; tus tsim qauv yuav tsum coj tus nqi tsawg kawg nkaus rau kev tswj hwm kev coj ua thiab daim ntawv khoom ntawm qhov kub ntawm qhov kev txaus siab, thiab yuav tsum lees paub nws tawm tsam cov ntawv tso cai pom zoo rau cov phiaj xwm airframe. Kev kho cua sov ntawm cov khoom siv raw thiab cov khoom tiav ua tiav raws li AMS 2770 rau wrought aluminium, thiab ib qho kev sib txawv ntawm qhov teev cia, quench ncua lossis kev laus ua tsis tau raws li qhov tso cai.
Al-Li qib yog pab pawg sib cais vim lithium txo qhov ntom ntawm li 3 feem pua ntawm 1 feem pua ntawm qhov sib ntxiv thiab nce qhov elastic modulus; qhov txiaj ntsig yog ib qho kev sib zog, sib zog ntawm lub zog me me. Lawv tus cwj pwm anisotropy thiab pob txha pob txha txawv ntawm cov pa 2xxx, yog li cov khoom muaj nqis tsuas yog siv los ntawm cov ntaub ntawv tsim nyog rau cov khoom tshwj xeeb.
Kev puas tsuaj rau kev ua siab ntev thiab kev qaug zog
Daim ntawv pov thawj kev xyaum nyob rau hauv 14 CFR 25.571 xav kom cov qauv khaws cov seem muaj zog tom qab tsis ua hauj lwm los yog tawg loj hlob, thiab cov tshuaj ntsuam xyuas qhov kev loj hlob yuav kwv yees tau. Cov naj npawb ua haujlwm yog qhov yooj yim-cov kab mob pob txha tawg tau ntsuas rau ASTM E399, qhov qaug zog tawg qhov loj hlob ntsuas rau ASTM E647, thiab qhov tsis tu ncua -amplitude qaug zog tus cwj pwm ntsuas rau ASTM E466 lossis sib npaug. Ntau -qhov kev puas tsuaj thiab kev puas tsuaj loj heev ua rau muaj kev xaiv ntawm qhov sib txuas ntawm qhov sib txuas thiab lub puab tsaig sib koom ua ke ntau dua li lub hauv paus hlau ua.
Corrosion, Stress Corrosion thiab tiv thaiv nto
SCC susceptibility ntawm 2xxx thiab 7xxx cov ntaub ntawv khoom raug soj ntsuam rau ASTM G47, thiab exfoliation kuj rau ASTM G34. Raws li txoj cai, T3 thiab T351 tempers ntawm 2024 muaj zoo qaug zog thiab toughness tab sis txwv corrosion kuj, thaum T73 thiab T7451 tempers ntawm 7075 txais lub zog nplua ntawm kwv yees li 10 mus rau 15 feem pua hauv kev pauv rau kev tiv thaiv kev ntxhov siab corrosion tawg nyob rau hauv luv luv transverse kev taw qhia. Clad sheet, anodising thiab chromate - cov txheej txheem hloov pauv dawb yog cov kev tiv thaiv saum npoo ib txwm muaj; qhov twg chromates raug cais tawm, zirconium-raws li pretreatments yog ib qho kev hloov pauv thiab xav tau lawv tus kheej tsim nyog.
Cov lus nug nquag
Q:Vim li cas 2024-T3 nyiam dua 7075-T6 rau daim tawv nqaij fuselage?
A: 2024-T3 sib xyaw ua ke ntau dua pob txha tawv thiab zoo dua qaug zog tawg kev loj hlob tsis kam nrog lub zog siv tau, uas txhawb kev tsim kev puas tsuaj rau kev ua siab ntev. 7075-T6 muaj zog dua tab sis muaj kev cuam tshuam ntau dua rau kev ntxhov siab corrosion tawg thiab muaj zog qis dua nyob rau hauv luv luv transverse kev taw qhia.
Q:T73 temper hloov li cas piv nrog T6?
A: Ob qho -kauj ruam dhau ntawm 7075 mus rau T73 thiab T7351 ua lag luam kwv yees li 10 mus rau 15 feem pua ntawm lub zog tensile rau qhov ua tau zoo dua rau kev ntxhov siab corrosion tawg thiab exfoliation, txheeb xyuas los ntawm ASTM G47 thiab ASTM G34 kuaj.
Q:Cov qauv twg kho cov qauv tsim rau aerospace txhuas?
A: Cov ntawv tso cai zoo li qub los ntawm cov ntawv pov thawj cov khoom pov thawj uas tau hais los ntawm qhov kev pab cuam airframe, cov khoom siv hauv paus yog tsim los rau AMS lossis ASTM specifications, thiab kev kho cua sov ua raws li AMS 2770. Cov qauv kev xeem yog ASTM E8 lossis ISO 6892-1 rau nro, ASTM E399 rau toughness thiab ASTM E647 rau kev loj hlob tawg.
Q:Cov phaj tuab coj txawv li cas ntawm daim ntawv nyias?
A: Cov phaj tuab qhia tau hais tias dhau los ntawm - cov khoom thickness gradient thiab qis dua cov khoom sib hloov. Tsim tso cai rau tuab 7050-T7451 los yog 7075-T7351 yuav tsum tau coj mus rau lub luv luv transverse kev taw qhia yog hais tias ib feem yog machined los ntawm qhov chaw ntawm lub phaj.
Q:Cov qauv txhuas puas tuaj yeem kho hauv kev pabcuam?
A: Yog lawm, tab sis kev kho yuav tsum rov qab kho qhov kev puas tsuaj rau qhov kev xav ntawm tus qauv tsim. riveted los yog bonded kho yog tsim nyog raws li ib tug tawg txoj kev loj hlob thiab residual zog cov txheej txheem, thiab tshav kub- kho tau 2xxx thiab 7xxx qhov chaw tsis tuaj yeem rov ua dua- hnub nyoog hauv zos yam tsis muaj kev cuam tshuam rau cov chaw nyob ib puag ncig.
Q:Puas yog Al-Li ib txwm yog qhov kev xaiv sib dua?
A: Tsis tau. Qhov kev txuag ceev yog qhov tseeb ntawm kwv yees li 3 feem pua ntawm lithium, tab sis siab dua anisotropy, kev tswj cov txheej txheem nruj dua thiab cov nqi khoom ntau dua txhais tau tias cov txiaj ntsig yuav tsum tau ua rau qhov tshwj xeeb nrog cov ntaub ntawv tsim nyog.
