Lub hom phiaj ntawm Alloy Development
Aluminium alloy txoj kev loj hlob yog kev tswj manipulation ntawm chemistry, ua thiab kho cua sov kom ncav cuag lub hom phiaj ua ke ntawm lub zog, toughness, corrosion kuj thiab formability. Aluminium ntshiab yog mos thiab du; txhua qhov kev lag luam alloy ntxiv cov ntsiab lus uas cuam tshuam nrog kev txav mus los lossis ua kom zoo dua microstructure. Txoj haujlwm engineering yog los txiav txim siab seb lub tshuab twg xa cov cuab yeej xav tau ntawm tus nqi tsim nyog, tom qab ntawd kho cov txheej txheem ua haujlwm uas ua rau cov txheej txheem ntawd rov ua dua hauv kev tsim khoom.
Tsib lub tswv yim tswj hwm kev coj ua niaj hnub no: nag lossis daus hardening, scandium microalloying, lithium ntxiv, ci hardening nyob rau hauv 6xxx daim ntawv, thiab sai solidification rau elevated - kev pab kub.
Ntxoov ntxoo Hardening hauv 7xxx Series
Nyob rau hauv Zn-Mg-Cu alloys, cov kuab tshuaj sib xyaw ua ke sib koom ua ke Guinier- thaj tsam Preston li ntawm 24 teev ntawm ntuj aging ntawm chav tsev kub. Tus txheej txheem T6 txoj kev rau cov alloys muaj kev kho mob ntawm kwv yees li 475℃rau 2 teev, dej quench, ces dag dag ntawm li 120℃rau 24 teev.
Thaum lub sij hawm tsim kev laus lub metastable η' theem, raws li MgZn2, nucleates thiab blocks dislocation motion, uas yog dab tsi ua rau lub zog nce. Kev lag luam tawm - tawm yog classic: tshaj - hnub nyoog T7 npau taws txi li ntawm 10% ntawm lub zog siab tshaj plaws kom tau txais txiaj ntsig zoo dua rau kev ntxhov siab - corrosion cracking, xws li hauv AA7075-T7351.
| Kauj ruam | Yam mob | Lub hom phiaj |
|---|---|---|
| Ntuj laus | Chav tsev kub, mus txog 24 teev | Tsim cov GP zones sib txuas |
| Kev kho mob | 475, 2 h | Soluble theem |
| Quench | Dej txias | Khaws ib qho kev daws teeb meem supersaturated |
| Artificial laus | 120 degree, 24 teev | Precipitates zoo η' (MgZn2) |
| Tshaj - laus | T7 condition | Trades ncov lub zog rau corrosion kuj |
Aerospace cov ntaub ntawv specifications feem ntau teem ib tug tsawg kawg nkaus dav hlau -strain tawg toughness saum 28 MPa·m1/2rau tuab tis-spar seem hauv siab-lub zog 7xxx phaj xws li AA7150-T7751. Fracture toughness yog ntsuas nrog cov txheej txheem ntawm ASTM B645, kom lub zog thiab kev puas tsuaj rau sab ntawm qhov yuav tsum tau ntsuas ntawm cov ntsiab lus sib piv.
Scandium Microalloying, Grain Refinement thiab Weldability
Ntxiv ib ncig ntawm 0.2% scandium rau ib qho txhuas alloy hloov pauv raws li - nrum cov qauv, txo cov nplej loj los ntawm kwv yees li 500 μm mus txog 10 μm. Lub mechanism yog tsim ntawm coherent Al3Sc nanoprecipitates, feem ntau yog 3-5 nm loj, uas pin ob qho tib si dislocations thiab grain ciam teb thiab tiv thaiv recrystallisation txawm tias tom qab ua haujlwm kub.
Cov cuab yeej nce siab yog qhov loj rau qhov sib ntxiv ntawm microalloying: hauv annealed Al-Mg-Sc cov ntaub ntawv lub zog tawm los ntawm li 150 MPa mus rau ib ncig ntawm 350 MPa. Scandium kuj tshem tawm kub- cracking susceptibility nyob rau hauv weldable siab -lub zog alloys xws li AA2219, uas yog vim li cas weldable Al-Cu- Sc variants yog siv rau loj cryogenic propellant tank domes. Qhov kev txwv tsis pub dhau ib txwm yog tus nqi, thiab kev siv zog ntau ntxiv tam sim no mus rau hauv kev rov qab los ntawm scandium los ntawm cov txheej txheem los ntawm - cov khoom thiab kuv cov tailings kom qhov sib ntxiv ua kev lag luam hauv ntau cov khoom lag luam.
Lithium Additions thiab ceev txo
Txhua 1% ntawm lithium ntxiv rau txhuas txo qhov ntom ntawm li 3% thiab nce qhov tawv nqaij, uas yog vim li cas lithium-muaj cov alloys txaus nyiam rau qhov hnyav- cov qauv tseem ceeb thiab rau cov tankage cryogenic. Alloys nrog kwv yees li 1.0 % Li, xws li 2195 tsev neeg, tau hloov 2219 hauv kev tso tawm - tsheb tankage thiab xa cov khoom hnyav hnyav rau ib lub tsheb.
| Feature | Paub meej |
|---|---|
| Precipitate theem | T1(Al2CuLi) |
| Kev laus kev xyaum | Duplex: 155℃rau 32 h, ces 190℃rau 24 teev |
| Melt kev huv | Nqus arc remelting tuav cov pa qis dua 10 ppm |
| Kev siv Airframe | AA2099-T86 phaj thiab ntawv rau daim tawv nqaij |
| Tshuab dhos | Xav tau cov ntxhia - roj- raws li cov dej txias vim lithium reactivity |
Kev kho mob duplex aging tshwm sim vim T1nag lossis daus qeeb thiab yuav tsum tau nucleated ntawm qhov kub thiab txias ua ntej qhov siab dua -kub theem loj hlob lub phaj- zoo li nag lossis daus uas muab cov hlau nws lub zog thiab qhov sib npaug. Kev huv huv yog qhov tseem ceeb sib npaug, vim lithium oxidises nkag tau yooj yim thiab cov oxide suav nrog ua cov neeg pib tawg.
Ci Hardening hauv 6xxx Series
Automotive lub cev panels siv Al-Mg-Si daim ntawv nyob rau hauv T4P mob, tsim thiab ces ntxiv dag zog rau hauv lub khw xim. Mg2Si '' koob, kwv yees li 2 los ntawm 5 nm, precipitate thaum lub sij hawm xim - ci voj voog, feem ntau 185℃rau 20 feeb, raising yield zog qhov twg lub vaj huam sib luag twb tsim.
AA6016-T4P daim ntawv nce mus txog kwv yees li 20% siab dua ncej- ci zog dua li ob-theem steel siv xws li DP780.
Electrocoat adhesion nyob ntawm kev ua kom cov hlau - mus rau - silicon ratio saum toj no txog 1.5: 1 kom qhov chaw chemistry nyob ib puag ncig los ntawm txoj kab ua ntej.
Kev sib tsoo kev ua tau zoo ntsuas raws li lub zog nqus tau txog li 15 kJ / kg, tawm tsam kwv yees li 8 kJ / kg rau cov seem hlau sib piv.
Loj ib leeg-daim hauv qab lub cev castings thiab cov qauv vaj huam sib luag hauv 6xxx alloys siv tib lub ci- txoj kev nyuaj, yog li formability hauv xovxwm thiab lub zog hauv kev pabcuam yog decoupled.
Rapid Solidification thiab siab -Tsub Alloys
Pa cam khwb cia txhuas alloys poob lub zog saum toj no txog 150℃vim hais tias lawv muaj zog precipitates coarsen. Fast solidification sidesteps qhov kev txwv no los ntawm kev tsim kom zoo dispersion ntawm thermally ruaj khov hais. Cov tshuaj tsuag tso tawm, piv txwv li, ua rau Al-8.5Fe-1.3V-1.7Si alloy uas tseem ncav cuag li 400 MPa lub zog ntawm 300 degree, txhawb nqa los ntawm cov pej xeem dispersoid saum 1017/m3ua 50nm al12(Fe, V)3Si particles uas tiv thaiv coarsening.
Additive manufacturing extends tib lub tswv yim mus rau complex duab. Selective laser melting yog siv los tsim turbocharger log thiab AlSi10Mg nres calipers nrog nplua, supersaturated cell lug thiab zoo seem kev ywj pheej, thaum Al-Ce-Mg alloys tsim rau compressor seem tiv taus qhov kev pab kub nyob ib ncig ntawm 250℃yam tsis poob lawv dispersion. Rau cov neeg tsim qauv, cov lus siv tau yog tias kev txhim kho alloy tsis yog ib qho teeb meem ntawm kev ntxiv cov ntsiab lus rau yaj; hmoov txoj kev, solidification tus nqi thiab kev kho cua sov yog tam sim no sib npaug zog levers.
Cov lus nug nquag
Q: Dab tsi yog nag lossis daus hardening hauv aluminium alloys?
Nws yog ntxiv dag zog los ntawm finely dispersed hais tsim thaum lub sij hawm laus. Solute yog tuav nyob rau hauv supersaturated tov los ntawm quenching, ces precipitates raws li GP zones thiab metastable theem uas cuam tshuam kev txav mus los.
Q: Vim li cas thiaj siv T7 temper es tsis txhob siab tshaj - laus T6?
T7 tshaj- laus muab ib ncig ntawm 10% ntawm lub siab tshaj plaws lub zog tab sis zoo heev txhim kho kev ntxhov siab- corrosion cracking kuj thiab seem stability, uas tseem ceeb rau tuab seem nyob rau hauv sustained load.
Q: Ntau npaum li cas scandium yuav tsum tau ua kom zoo dua cov qauv nplej?
Kwv yees li 0.2% feem ntau yog txaus kom txo tau raws li - nrum nplej loj los ntawm kwv yees li 500 μm mus txog 10 μm los ntawm Al3Sc nanoprecipitates ntawm 3-5 nm.
Q: Vim li cas lithium - muaj cov alloys hnub nyoog hauv ob theem?
T1(Al2CuLi) nag lossis daus qeeb, yog li duplex laus ntawm 155℃ces 190℃nucleates theem ua ntej thiab tom qab ntawd nws loj hlob mus rau qhov loj uas muab lub zog zoo tshaj plaws thiab tawv.
Q: Dab tsi txwv ci - hardened 6xxx daim ntawv nyob rau hauv lub cev panels?
Formability nyob rau hauv xovxwm thiab stability ntawm nto chemistry rau electrocoat adhesion, uas yog vim li cas cov hlau - rau - silicon ratio yog tswj saum toj no hais txog 1.5: 1.
Q: Lub tshuab twg tso cai rau txhuas ua haujlwm siab tshaj 250 degree?
Ceev ceev solidification ua. Nws tsim kom muaj qhov ntom ntom ntom ntawm cov khoom ruaj khov, xws li Al12(Fe, V)3Si, uas tiv taus coarsening ntawm qhov kub thiab txias.
