Raws li cov khoom siv ua pa hlau uas tau nce nrawm rau hauv lub sijhawm tsis ntev los no, tsheb thiab muaj zog tsis ntev los no, thiab muaj zog tshwj xeeb, thiab kev ua haujlwm 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 cov txheej txheem vuam txwv txoj kev txhim kho ntawm aluminium alloy 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.
Txheej txheem cej luam ntawm Aluminium Alloy Properties
Aluminium yog cov khoom siv hlau hnyav heev nrog qhov ceev ntawm tsuas yog 2.7g / cm3, uas yog kwv yees li 36% ntawm qhov ntom ntawm cov hlau. Kev siv aluminium alloy los tsim cov khoom siv kho tshuab tuaj yeem txo qhov hnyav thiab ua tiav cov txiaj ntsig 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 alloys muaj zoo machinability thiab recyclability. Yog hais tias lub txiav kuj coefficient ntawm cov feem ntau machinable magnesium alloy yog xam tau tias yog 1, lub txiav tsis kam ntawm lwm yam hlau yog qhia nyob rau hauv Table 2. Nws yuav pom tau hais tias cov txiav tsis kam ntawm txhuas alloy yog tsawg tshaj li ntawm tooj liab, hlau thiab lwm yam. cov ntaub ntawv, thiab cov txheej txheem txiav yog yooj yim dua.
Aluminium alloy vuam yam ntxwv
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 qis dua modulus ntawm 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%, 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. Internal kev nyuaj siab ntawm weld thiab rigidity ntawm welded sib koom. Loj dua, nws yog ib qho yooj yim los tsim kom muaj kev ntxhov siab loj hauv cov aluminium alloy sib koom ua ke, ua rau cov vuam loj thiab deformation, tsim cov kab nrib pleb, yoj deformation thiab lwm yam tsis xws luag.
Ablative evaporation
Lub melting point ntawm txhuas yog 660 degree thiab lub boiling point yog 2647 degree, uas yog qis dua lwm yam hlau ntsiab 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 rau tawg thiab tsim 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 cov aluminium alloy muaj. ib qho boiling point, uas yog ib qho yooj yim rau evaporate thiab hlawv nyob rau hauv lub instantaneous kub kub ntawm welding, thiab cov txaws generated los ntawm tawg yuav kuj tshem tawm ib feem ntawm cov tee dej, uas inevitably hloov lub vuam seam cheeb tsam. Cov tshuaj muaj pes tsawg leeg tsis tsim nyog rau kev ua haujlwm ntawm cov pob qij txha 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.
Khoom 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 los ua Al2O3 nrog lub siab melting point (txog 2050 degree, thaum lub melting point ntawm txhuas yog 660 degree, uas yog txawv heev). Cov oxides yog ntom thiab muaj zog hardness, thiab lawv 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 me me slag inclusions uas tsis yooj yim rau paug, uas tsis tsuas cuam tshuam rau lub microstructure ntawm lub vuam, tab sis kuj yog nquag 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 qis dua li ntawm nws cov oxide, thiab nws muaj zog heev thiab yooj yim rau oxidize. Thaum lub sij hawm welding txheej txheem, aluminium alloy yog melted ntawm high kub los tsim ib tug molten pas dej ua ke. 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 hauv ib daim ntawv. Txij li cov xim ntawm cov molten oxide zaj duab xis tsis txawv ntau ntawm lub xeev molten ntawm aluminium alloy, thiab vim hais tias ntawm cov kev pab them nqi ntawm cov oxide zaj duab xis, nws yog ib qho 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 heev thiab ua rau vuam kub. Kev tawg loj hauv cheeb tsam ua rau cov duab thiab cov khoom ntawm cov hlau weld.
Nyob rau hauv qhov kev txiav txim ntawm instantaneous siab zog ntawm vuam qhov chaw kub, ib tug loj npaum li cas ntawm hydrogen 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 maj mam txo, uas yog lub ntsiab ua rau lub pores thaum lub sij hawm vuam txheej txheem. vim li cas. Vim yog qhov ceev ceev thiab qhov ntom ntom ntawm aluminium alloys, hydrogen pores ntawm ntau qhov sib txawv yog tsim thaum lub sij hawm sai solidification ntawm weld. Cov pores yuav txuas ntxiv mus ntxiv thiab nthuav dav thaum lub sij hawm vuam txheej txheem, nws thiaj li tsim cov pores pom thiab txo cov txheej txheem ntawm kev sib koom ua ke. Ntawm chav kawm, tiam ntawm pores tsis tas tsim thaum lub sij hawm vuam txheej txheem. Vim muaj kev cuam tshuam ntawm kev siv tshuab casting, lub hauv paus hlau nws tus kheej tseem yuav tsim cov pores thaum lub sij hawm casting txheej txheem. Thaum lub sij hawm vuam, qhov tsis tu ncua ntawm cov hluav taws xob tawm hluav taws xob thiab lub siab sab hauv ua rau lub qhov pores hauv lub hauv paus hlau nthuav dav los ntawm cua sov los yog sib xyaw ua ke los tsim cov pores. Nrog rau qhov nce ntawm vuam cua sov input, 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 qhuav qhuav ua ntej siv. Thaum lub sij hawm vuam, qhov tam sim no yuav tsum tau tsim kom tsim nyog kom ntev lub neej ntawm lub pas dej ua ke molten thiab cia lub sij hawm txaus rau hydrogen kom precipitate, yog li tswj cov tsim ntawm pores.
Kev faib tawm ntawm aluminium alloy vuam technology
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, aluminium alloy vuam tshuab tau ua tiav zoo. 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.
TIG welding
Tungsten Inert Gas Vuam (TIG) yog ib qho inert roj arc 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 yog kis ntawm ob lub electrodes raws li ib tug shielding roj los tiv thaiv lub arc, thiab cov hlau thiab lub hauv paus hlau yog melted los ntawm instantaneous high-voltage paug, thiab aluminium alloy qhov chaw yog welded thiab tsim, thiab Weld kho thiab kho qhov tsis xws luag casting.
Feem ntau muaj cov yam ntxwv nram 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 tus nqi qis;
Lub tshav kub-cuam tshuam cheeb tsam yog nqaim, deformation ntawm cov 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;
Cov txheej txheem vuam kev ua tau zoo thiab ruaj khov, thiab vuam seam yog ntom thiab zoo nkauj.
MIG Vuam
MIG (GMA-Gas Hlau Arc Vuam) thiab TIG yog ob qho tib si inert gas shielded welding, qhov txawv yog tias TIG vuam siv lub tungsten electrode raws li ib tug taag electrode, thaum MIG vuam siv cov muab tub lim cov ntaub ntawv nws tus kheej raws li ib tug electrode.
Txawm li cas los xij, daim ntawv thov txheej txheem ntawm aluminium alloy MIG welding yog qhov txwv tsis pub dhau, vim tias cov hlau mos ntawm txhuas ua rau cov xaim tsis zoo, thiab cov molten aluminium nyhav tsim qhov tshwm sim ntawm "dai yam tsis muaj dej" thaum lub sij hawm vuam, uas yooj yim ua rau te. txaws. Qhov zoo dua yog tias MIG vuam yog nrawm dua TIG vuam, thiab qhov 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 raws li ib tug.
Qhov zoo ntawm laser vuam yog tias qhov vuam taw tes ntawm qhov kev txiav txim me me, lub zog hluav taws xob muaj zog yog cov concentrated, thiab nws muaj peev xwm los vuam tuab daim hlau, nrog rau qhov chaw nqaim tshav kub thiab me me vuam deformation. Txawm li cas los xij, 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 ceev qhia tau hais tias thaum lub zog ceev ntawm lub workpiece mus txog ntau tshaj 107W / cm2, cov hlau nyob rau hauv lub cua sov cheeb tsam yuav vaporized 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 qhov. Lub pas dej molten, Lub qhov me me no yog qhov chaw rau kev hloov cua sov, 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 welding. Txhawm rau kom tsis txhob muaj teeb meem ntawm lub pas dej tsis sib xws uas 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 cov pores. .
Kev sib txhuam do vuam
Friction do welding (Friction do Welding, FSW) yog ib qho tshiab-theem kev koom tes thev naus laus zis tsim los ntawm kev sib txhuam vuam tshuab. Nyob rau ntawm lub interface yuav tsum tau welded, thaum lub taub hau stirring nce mus rau lub weld, qhov kub ntawm cov khoom siv vuam nce, thiab cov hlau yas ua rau cov yas muaj zog 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;
Cov cuab yeej cuab tam ntawm cov vuam yog zoo;
Cov txheej txheem vuam yog yooj yim, kev lag luam thiab ib puag ncig tus phooj ywg.
