Raws li cov khoom siv uas ua rau engineering uas tau nce nrawm rau hauv ib lub chaw tsis ntev los no, lub zog tsis ntev los no, lub zog tsis ntev los no, thiab muaj zog tshwj xeeb, thiab cov zoo corrosion tsis kam. .
Txawm li cas los xij, ib qho teeb meem xws li kev tsis zoo weldability thiab kev ua haujlwm tsis zoo ntawm txheej txheej hauv vuam txwv kev txhim kho ntawm aluminium alloy structural qhov chaw. Yog li ntawd, aluminium alloy vuam tshuab tau dhau los ua ib qho kev tshawb fawb tseem ceeb ntawm ntau tus kws tshawb fawb hauv tsev thiab txawv teb chaws.
Aluminium alloy kev ua tau zoo txheej txheem cej luam
Aluminium yog cov khoom siv hlau uas muaj qhov ntom ntom ntawm 2.7g / cm3, uas yog kwv yees li 36 feem pua ntawm cov hlau ntom. Aluminium alloy yog siv los tsim cov khoom siv kho tshuab, uas tuaj yeem txo qhov hnyav thiab ua tiav cov teebmeem ntawm lub teeb yuag, txuag hluav taws xob thiab txo qis emission.
Lub zog tshwj xeeb thiab tshwj xeeb nruj ntawm aluminium alloy yog siab dua 45 steel thiab ABS yas. Kev siv cov khoom siv aluminium alloy yog qhov tsim nyog rau kev tsim khoom ntawm cov khoom sib xyaw nrog cov kev xav tau siab rigidity.
Aluminium alloy muaj zoo thermal conductivity, hluav taws xob conductivity thiab corrosion kuj. Qhov kev ua tau zoo ntawm A380 aluminium alloy thiab lwm yam ntaub ntawv tau qhia hauv Table 1.
Aluminium alloy muaj zoo machinability thiab recyclability. Yog hais tias nws yog assumed tias qhov kev txiav kuj coefficient ntawm qhov yooj yim tshaj plaws txiav magnesium alloy yog 1, lub txiav tsis kam ntawm lwm yam hlau yog qhia nyob rau hauv Table 2. Nws yuav pom tau hais tias lub txiav tsis kam ntawm txhuas alloy yog tsawg tshaj li ntawm tooj liab, hlau. thiab lwm yam ntaub ntawv, thiab cov txheej txheem txiav yog ib qho yooj yim.
Aluminium alloy vuam yam ntxwv
Muaj kev cuam tshuam los ntawm lub cev thiab tshuaj lom neeg ntawm aluminium alloys, muaj qee yam teeb meem hauv cov txheej txheem vuam. Tam sim no aluminium alloy welding feem ntau muaj cov teeb meem hauv qab no: thermal stress, ablation evaporation, khoom inclusions, pore collapse, thiab lwm yam.:
Thermal Stress
Aluminium alloys muaj ntau dua coefficient ntawm thermal expansion thiab ib tug me me modulus elasticity. Thaum lub sij hawm vuam txheej txheem, vim qhov loj deformation thiab loj linear expansion coefficient ntawm aluminium alloy, lub ntim shrinkage tus nqi thaum lub sij hawm solidification yog hais txog 6 feem pua, thiab qhov txias npaum li cas thiab cov thawj crystallization tus nqi ntawm lub molten pas dej ua ke yog ceev, uas ua rau lub welding tus nqi yog 6%. Internal kev nyuaj siab ntawm weld thiab rigidity ntawm welded sib koom. Loj dua, nws yog ib qho yooj yim los ua kom muaj kev ntxhov siab ntau dua hauv kev sib koom ua ke ntawm aluminium alloy, ua rau muaj kev ntxhov siab ntau dua thiab deformation, ua rau muaj qhov tsis xws luag xws li tawg thiab yoj deformation.
Ablation evaporation
Aluminium muaj qhov melting point ntawm 660 degree thiab qhov kub ntawm 2647 degree, uas yog qis dua lwm yam hlau xws li tooj liab thiab hlau. Thaum lub sij hawm vuam txheej txheem, yog tias vuam kub siab dhau lawm, nws yog ib qho yooj yim uas yuav ua rau tawg thiab daim ntawv spatter, tshwj xeeb tshaj yog nyob rau hauv high-zog beam vuam, raws li qhia nyob rau hauv daim duab 1. Tsis tas li ntawd, ib co ntawm cov alloying ntsiab ntxiv rau aluminium alloy. muaj qhov kub tsis tshua muaj kub, uas yooj yim heev rau evaporate thiab hlawv ntawm qhov kub thiab txias ntawm vuam tam sim ntawd, thiab cov txaws tsim los ntawm kev tawg kuj tseem yuav tshem tawm ib feem ntawm cov kua tee, uas inevitably hloov qhov chaw weld. Cov tshuaj muaj pes tsawg leeg tsis tsim nyog rau kev ua haujlwm ntawm kev sib koom ua ke ntawm welded. Yog li ntawd, txhawm rau txhawm rau txhawm rau txhawm rau kub kub ablation, vuam hlau lossis lwm yam khoom siv vuam nrog cov ntsiab lus kub kub siab dua cov hlau hauv paus feem ntau siv thaum vuam.
kev suav nrog
Cov khoom siv tshuaj lom neeg ntawm txhuas yog cov nquag nquag thiab yooj yim oxidized. Thaum lub sij hawm vuam txheej txheem, qhov saum npoo ntawm aluminium alloy yog oxidized rau daim ntawv Al2O3 nrog lub siab melting point (li 2050 degree C, thaum lub melting point ntawm txhuas yog 660 degree C, uas yog txawv heev). Cov oxides yog ntom thiab muaj zog hardness, thiab sib tov nyob rau hauv molten alloy kua nrog tsawg ntom nyob rau hauv lub molten pas dej ua ke cheeb tsam, uas yog ib qho yooj yim rau tsim zoo slag slag thiab yog ib qho nyuaj rau tso tawm, uas tsis tsuas yog cuam tshuam rau cov qauv ntawm cov weld, Tab sis kuj yooj yim tsim electrochemical corrosion, uas yuav ua rau cov neeg kho tshuab cov khoom ntawm welded pob qij txha txo, thiab Al2O3 npog lub molten pas dej ua ke thiab zawj, uas cuam tshuam rau lub vuam ntawm alloys thiab txo cov microstructure thiab cov khoom ntawm welded pob qij txha.
Lub plab zom mov
Lub melting point ntawm aluminium alloy yog tsawg dua li ntawm nws cov oxide, thiab nws cov xwm yog cus ciav thiab yooj yim rau oxidize. Thaum lub sij hawm vuam txheej txheem, aluminium alloy tsim ib lub pas dej molten vim yog kub melting. Cov txhuas nyob rau saum npoo ntawm lub pas dej molten yog oxidized los ua ib zaj duab xis oxide, uas npog lub pas dej molten nyob rau hauv lub xeev ruaj khov. Txij li cov xim ntawm oxide zaj duab xis tom qab melting tsis ntau txawv ntawm cov molten aluminium alloy, thiab vim hais tias ntawm cov kev pab them nqi ntawm oxide zaj duab xis, nws yog ib qhov nyuaj rau soj ntsuam cov degree ntawm melting ntawm aluminium alloy molten pas dej ua ke thaum lub sij hawm vuam txheej txheem. , yog li nws yog ib qho yooj yim los ua kom qhov kub thiab txias siab dhau, ua rau cov vuam kub cuam tshuam Cov feem ntau ntawm cov cheeb tsam tawg, rhuav tshem cov duab thiab cov khoom ntawm cov hlau weld.
Nyob rau hauv qhov kev txiav txim ntawm instantaneous siab zog ntawm vuam qhov chaw tshav kub, ib tug loj npaum li cas ntawm hydrogen roj yog yaj nyob rau hauv lub alloy kua. Tom qab lub vuam tiav lawm, raws li qhov kub ntawm lub pas dej molten txo, lub solubility ntawm cov roj kuj maj mam txo, uas yog lub ntsiab ua rau lub pores nyob rau hauv lub vuam txheej txheem. vim li cas. Vim hais tias lub solidification ceev ntawm aluminium alloy yog ceev heev thiab qhov ceev yog tsawg, hydrogen pores ntawm ntau qhov sib txawv yog tsim thaum lub sij hawm sai solidification ntawm weld. Cov pores no yuav txuas ntxiv mus ntxiv thiab nthuav dav thaum lub sij hawm vuam txheej txheem, nws thiaj li tsim pom cov pores loj thiab txo cov txheej txheem ntawm kev sib koom ua ke. Ntawm chav kawm, lub pores tsis tas tsim thaum lub sij hawm vuam txheej txheem. Vim muaj kev cuam tshuam ntawm cov txheej txheem casting technology, lub hauv paus hlau nws tus kheej kuj yuav tsim pores thaum lub sij hawm casting txheej txheem. Thaum lub sij hawm welding, lub tshav kub input thiab sab hauv lub siab hloov tas li, ua rau cov thawj pores nyob rau hauv lub hauv paus hlau yuav nthuav los yog ua ke nrog ib leeg los tsim weld pores. Raws li lub vuam cua sov input nce, lub pores kuj yuav nce. Yog li ntawd, txhawm rau tswj hwm qhov chaw ntawm hydrogen, cov khoom siv vuam yuav tsum tau ua kom nruj nruj ua ntej siv. Thaum lub sij hawm vuam, qhov tam sim no yog tsim nyog kom ntev lub neej ntawm lub pas dej ua ke molten thiab muab sij hawm txaus rau hydrogen kom precipitate, yog li tswj qhov tsim ntawm pores.
duab
Fig.2 Tsim thiab convergence ntawm stomata
Kev faib tawm ntawm aluminium alloy vuam tshuab
Nrog rau kev nthuav dav ntawm daim ntawv thov ntau yam ntawm aluminium alloys, ntau thiab ntau cov teeb meem tau qhia. Nrog rau kev nce qib ntawm kev tshawb fawb, vuam tshuab ntawm aluminium alloy tau tsim zoo heev. Tam sim no, feem ntau yog tungsten argon arc vuam (TIG), molten inert gas welding (MIG), laser vuam (LBW), kev sib txhuam do vuam (FSW) tos.
Gas tungsten arc vuam
Tungsten Inert Gas Vuam (TIG) yog ib qho inert roj shielded vuam thiab yog feem ntau siv vuam txoj kev. Thaum vuam, tungsten electrode thiab vuam nto yog siv los ua electrodes, thiab helium los yog argon gas kis ntawm ob lub electrodes los tiv thaiv cov arc, thiab cov hlau thiab lub hauv paus hlau yog melted los ntawm instantaneous high-voltage paug, thiab cov aluminium alloy qhov chaw yog welded thiab tsim, thiab Vuam thiab kho ntawm casting defects.
Nws feem ntau muaj cov yam ntxwv hauv qab no:
Yooj yim rau kev khiav lag luam, hloov tau yooj yim thiab tswj tau, hloov tau rau ntau yam kev ua haujlwm thiab ib puag ncig, thiab tus nqi qis;
Lub tshav kub-cuam tshuam cheeb tsam yog nqaim, thiab deformation ntawm welded sib koom yog me me nyob rau hauv cov xwm txheej ntawm txaus xaim pub, thiab kev ua tau zoo ntawm kev sib koom ua ke yog siab;
Qhov kev ua tau zoo ntawm cov txheej txheem vuam yog qhov zoo thiab ruaj khov, thiab cov vuam seam yog ntom thiab zoo nkauj.
MIG vuam
Ob leeg MIG (GMA-Gas Hlau Arc Vuam) thiab TIG yog inert gas shielded vuam. Qhov txawv yog tias TIG vuam siv tungsten electrodes raws li cov electrodes ruaj khov, thaum MIG vuam siv cov khoom siv hlau uas nws tus kheej ua electrodes.
Nyob rau hauv cov hlau inert roj shielded vuam txheej txheem ntawm txhuas alloy, qhov voltage thiab tam sim no ua nyob rau hauv lub kawg ntawm lub electrode ntawm lub vuam hlau, thiab ib tug instantaneous siab siab yog generated ntawm lub electrode thiab lub hauv paus hlau, uas melts lub hauv paus hlau thiab cov. zawj, thiab cov tee dej ntawm qhov kawg ntawm cov hlau ntog tawm thiab hloov vertically mus rau lub hauv paus hlau. Ntawm lub pas dej molten ntawm cov khoom, ib qho chaw weld yog tsim.
Txawm li cas los xij, daim ntawv thov txheej txheem ntawm aluminium alloy MIG vuam yog qhov txwv, vim tias qhov muag ntawm cov hlau txhuas ua rau cov hlau tsis zoo, thiab cov txhuas txhuas molten yog ib qho tshwm sim ntawm "dai tab sis tsis poob" thaum lub sij hawm vuam, uas yog ib qho yooj yim. ua kom cov dej tawg. Qhov kom zoo dua yog tias MIG vuam yog ceev dua TIG vuam, thiab vuam txav ntau me me thaum vuam loj workpieces. Los ntawm kev kho cov hlau pub ceev, qhov vuam efficiency tuaj yeem ncav cuag ob peb meters ib feeb.
laser vuam
Laser beam welding (Laser Beam Vuam LBW) siv lub zog laser pulses kom sov cov khoom hauv cheeb tsam me me. Lub zog ntawm cov hluav taws xob laser diffuses rau sab hauv ntawm cov khoom siv los ntawm cov khoom siv hluav taws xob, thiab cov khoom yog melted los ua ib lub pas dej molten. Tom qab solidification, cov khoom yog txuas rau hauv ib qho.
Qhov kom zoo dua ntawm laser vuam yog tias vuam qhov taw tes me me, lub zog hluav taws xob muaj zog yog qhov muaj zog, nws muaj peev xwm ntawm vuam tuab daim hlau, qhov chaw kub-tshuaj yog nqaim, thiab vuam deformation me me. Tab sis tib lub sijhawm, laser vuam muaj qhov yuav tsum tau ua rau vuam qhov chaw, cov khoom siv vuam kim, thiab cov nqi vuam siab. Rau cov ntaub ntawv hlau xws li txhuas thiab magnesium, laser reflectivity yog siab, thiab ncaj welding yog nyuaj.
Irradiating cov ntaub ntawv nrog lasers nrog sib txawv zog density qhia tau hais tias thaum lub hwj chim ceev ntawm lub workpiece ncav cuag ntau tshaj 107W / cm2, cov hlau nyob rau hauv lub cua sov cheeb tsam yuav gasified nyob rau hauv ib tug luv luv lub sij hawm, thiab cov roj yuav converge mus rau hauv ib tug me me qhov nyob rau hauv lub workpiece. molten pas dej ua ke thiab tsim ib lub qhov me me yog qhov chaw rau cov cua sov hloov, thiab lub pas dej molten yog tsim nyob ze ntawm lub qhov me me, uas yog qhov "keyhole" nyhuv ntawm laser sib sib zog nqus nqus vuam. Txhawm rau kom tsis txhob muaj qhov tsis sib xws ntawm lub pas dej molten tshwm sim los ntawm qhov tshwm sim no, nws muaj peev xwm txo tau lub zog laser, ua kom cov vuam ceev los yog tswj cov remelting ntawm thaj tsam nugget kom tshem tawm cov npuas hauv thaj tsam fusion thiab txo cov tiam ntawm qhov pores. .
kev sib txhuam do welding
Friction do welding (Friction do Welding, FSW) yog ib hom tshiab ntawm cov khoom sib txuas thev naus laus zis raws li kev sib txhuam vuam tshuab. Nyob rau ntawm lub interface yuav tsum tau welded, thaum lub taub hau stirring nce raws lub weld seam, qhov kub ntawm cov khoom siv vuam nce, thiab cov hlau yas ua rau muaj zog yas deformation nyob rau hauv qhov kev txiav txim ntawm txhua yam stirring thiab chim siab, thiab tsim ib tug ntom khoom-theem kev twb kev txuas. tom qab diffusion thiab recrystallization.
Piv nrog cov txheej txheem vuam tsoos, FSW thev naus laus zis muaj qhov zoo hauv qab no:
Tsawg vuam kub thiab me me vuam deformation;
Zoo mechanical zog ntawm weld;
Cov txheej txheem vuam yog yooj yim, kev lag luam thiab ib puag ncig tus phooj ywg.
Cov teeb meem tseem ceeb thiab kev tshawb fawb tsom
Nrog rau daim ntawv thov ntawm txhuas alloys nyob rau hauv ntau thiab ntau industries, qhov teeb meem ntawm nws kho kev twb kev txuas tau kuj attracted cov xim ntawm ntau thiab ntau scholars. Los ntawm ntau yam kev ntsuam xyuas vuam ntawm aluminium alloys, nws pom tau tias kev loj hlob ntawm kev kho tshuab tseem tsis tau raws li qhov kev xav tau ntawm kev lag luam, thiab tseem muaj ntau yam teeb meem hauv nws.
Gas tungsten arc welding thiab hlau inert gas shielded vuam yog ob txoj kev siv vuam ntau tshaj plaws tam sim no, tab sis ob lub thev naus laus zis no muaj thaj tsam dav cua sov, thiab cov hlau vuam yuav tsum tau yaj thiab tom qab ntawd khov kho, uas muaj kev cuam tshuam rau. tus qauv. Loj dua, thiab qhov seem ntawm qhov kev ntxhov siab yog siab, ua rau muaj kev cuam tshuam loj heev rau cov khoom siv kho tshuab ntawm kev sib koom tes. Laser vuam lub zog nqaj yog qhov siab, thiab nws yooj yim tus nqi ntau, tab sis nws kim heev rau kev txwv cov npe ntawm cov ntawv thov. Kev sib txhuam do vuam muab kev daws teeb meem rau cov teeb meem ntawm tshav kub, tab sis kev sib txhuam txhuam vuam yuav tsum muaj kev ntxhov siab loj thiab kev tsav tsheb rau pem hauv ntej, thiab cov khoom siv feem ntau nyuaj thiab loj, uas txwv nws txoj kev loj hlob.
Lub hom phiaj ntawm kev tshawb fawb yav tom ntej ntawm cov ncauj lus muaj feem cuam tshuam yuav tsum yog ntawm cov hauv qab no:
Pib los ntawm lub hauv paus ntawm fusion vuam, kho cov qauv vuam hlau, ntxiv cov ntsiab lus tsis tshua muaj hauv ntiaj teb los yog xaiv tus nqi tsim nyog ntawm vuam activator los tswj cov vuam deformation, txo kev ntxhov siab, thiab txo qhov tsim ntawm qhov pores.
Raws li kev nthuav dav ntawm cov peev txheej thiab kev siv cov alloys, lawv feem ntau yog siv los ua ke nrog cov khoom sib txawv, yog li nws yog ib qho tsim nyog yuav tsum tau ua cov txheej txheem vuam ntawm cov hlau sib txawv kom tau txais cov pob qij txha zoo.
Ua kev tshawb fawb txog kev sib txuas ntawm cov khoom siv hluav taws xob sib xyaw, xws li TIG-laser hybrid vuam, laser sib txhuam txhuam txhuam, txhawm rau kom tau txais qhov zoo tshaj plaws weld kev ua haujlwm.
