1. Kulimba kwamphamvu
Kapangidwe ka aluminiyamu ndi aluminiyamu ndi koipa, makamaka chifukwa filimu ya oxide pamwamba ndi yovuta kuchotsa. Aluminiyamu ili ndi mphamvu yayikulu ya okosijeni. N'zosavuta kupanga filimu ya oxide yolimba, yokhazikika komanso yosungunuka kwambiri ya Al2O3 pamwamba. Nthawi yomweyo, aluminiyamu yokhala ndi magnesium imapanganso filimu ya oxide yokhazikika kwambiri ya MgO. Zimalepheretsa kwambiri kunyowa ndi kufalikira kwa solder. Ndipo zimakhala zovuta kuchotsa. Panthawi yopangira, njira yopangira brazing imatha kuchitika pokhapokha ngati pali flux yoyenera.
Kachiwiri, kugwiritsa ntchito aluminiyamu ndi aluminiyamu yopangira aluminiyamu ndi kovuta. Malo osungunuka a aluminiyamu ndi aluminiyamu si osiyana kwambiri ndi achitsulo chodzaza aluminiyamu chomwe chimagwiritsidwa ntchito. Kutentha komwe mungasankhe popangira aluminiyamu ndi kochepa kwambiri. Kuwongolera kutentha pang'ono kosayenera ndikosavuta kuyambitsa kutentha kwambiri kapena kusungunuka kwa chitsulo choyambira, zomwe zimapangitsa kuti ntchito yopangira aluminiyamu ikhale yovuta. Ma aluminiyamu ena olimbikitsidwa ndi kutentha angayambitsenso zinthu zofewa monga kukalamba kwambiri kapena kunyowa chifukwa cha kutentha kwa aluminiyamu, zomwe zimachepetsa mphamvu ya malo olumikizirana. Pakupangira malawi, zimakhala zovuta kuweruza kutentha chifukwa mtundu wa aluminiyamu susintha pakutentha, zomwe zimawonjezeranso zofunikira pamlingo wa ntchito ya wogwiritsa ntchito.
Kuphatikiza apo, kukana dzimbiri kwa zolumikizira za aluminiyamu ndi aluminiyamu kumakhudzidwa mosavuta ndi zitsulo ndi ma fluxes odzaza. Mphamvu ya ma electrode ya aluminiyamu ndi aluminiyamu ndi yosiyana kwambiri ndi ya solder, zomwe zimachepetsa kukana dzimbiri kwa cholumikizira, makamaka pa cholumikizira chofewa. Kuphatikiza apo, ma fluxes ambiri omwe amagwiritsidwa ntchito popangira aluminiyamu ndi aluminiyamu ali ndi dzimbiri lamphamvu. Ngakhale atatsukidwa pambuyo popangira, mphamvu ya ma fluxes pa kukana dzimbiri kwa zolumikizira sizidzathetsedwa kwathunthu.
2. Zipangizo zomangira
(1) Kuyika zitsulo za aluminiyamu ndi aluminiyamu ndi njira yomwe imagwiritsidwa ntchito kawirikawiri, chifukwa kapangidwe kake ndi mphamvu ya ma electrode ya zitsulo zodzaza ndi zitsulo zoyambira zimasiyana kwambiri, zomwe zimapangitsa kuti chiwalocho chizizire mosavuta. Kuyika kofewa kumagwiritsa ntchito zinc based solder ndi tin lead solder, zomwe zingagawidwe m'magawo awiri: solder yotsika kutentha (150 ~ 260 ℃), solder yotenthetsera yapakatikati (260 ~ 370 ℃) ndi solder yotenthetsera kwambiri (370 ~ 430 ℃) malinga ndi kutentha komwe kuli. Pamene solder ya tin lead ikugwiritsidwa ntchito ndipo mkuwa kapena nickel yayikidwa kale pamwamba pa aluminiyamu kuti igwiritsidwe ntchito, dzimbiri pamalo olumikizirana limatha kupewedwa, kuti pakhale kukana kwa dzimbiri kwa chiwalocho.
Kuphimba zitsulo za aluminiyamu ndi aluminiyamu kumagwiritsidwa ntchito kwambiri, monga chitsogozo cha zosefera, evaporator, radiator ndi zina. Zitsulo zodzaza zopangidwa ndi aluminiyamu zokha ndi zomwe zingagwiritsidwe ntchito popanga zitsulo za aluminiyamu ndi aluminiyamu, zomwe zitsulo za aluminiyamu silicon filler ndi zomwe zimagwiritsidwa ntchito kwambiri. Kukula kwapadera kwa ntchito ndi mphamvu yodula ya zolumikizira za braze zawonetsedwa mu Table 8 ndi tebulo 9 motsatana. Komabe, malo osungunuka a solder iyi ali pafupi ndi a chitsulo choyambira, kotero kutentha kwa kutentha kuyenera kulamulidwa mosamala komanso molondola panthawi yophimba zitsulo kuti chitsulo choyambira chisatenthe kwambiri kapena kusungunuka.
Gome 8 kuchuluka kwa momwe zitsulo zodzaza zitsulo zimagwiritsidwira ntchito popanga aluminiyamu ndi aluminiyamu
Gome 9 mphamvu yodula ya aluminiyamu ndi zolumikizira za aluminiyamu zokongoletsedwa ndi zitsulo zodzaza aluminiyamu za silicon
Chotsukira cha silicon cha aluminiyamu nthawi zambiri chimaperekedwa mu mawonekedwe a ufa, phala, waya kapena pepala. Nthawi zina, mbale zosungunula zokhala ndi aluminiyamu ngati maziko ndi chotsukira cha silicon cha aluminiyamu ngati chophimba zimagwiritsidwa ntchito. Mtundu uwu wa mbale zosungunula zimapangidwa ndi njira ya hydraulic ndipo nthawi zambiri zimagwiritsidwa ntchito ngati gawo la zigawo zosungunula. Pakusungunula, chitsulo chodzaza brazing pa mbale yosungunula chimasungunuka ndikuyenda pansi pa mphamvu ya capillary ndi mphamvu yokoka kuti chidzaze malo olumikizirana.
(2) Mpweya wothira ndi woteteza wa aluminiyamu ndi aluminiyamu, flux yapadera nthawi zambiri imagwiritsidwa ntchito kuchotsa filimuyo. organic flux yochokera ku triethanolamine, monga fs204, imagwiritsidwa ntchito ndi solder yofewa yotsika kutentha. Ubwino wa flux iyi ndikuti ili ndi mphamvu yochepa ya dzimbiri pa chitsulo choyambira, koma imapanga mpweya wambiri, zomwe zimakhudza kunyowa ndi kutsekeka kwa solder. Reactive flux yochokera ku zinc chloride, monga fs203 ndi fs220a, imagwiritsidwa ntchito ndi solder yofewa yotentha kwambiri komanso yotentha kwambiri. Reactive flux imawononga kwambiri, ndipo zotsalira zake ziyenera kuchotsedwa pambuyo pa brazing.
Pakadali pano, kulimba kwa aluminiyamu ndi zitsulo zotayidwa kumayendetsedwabe ndi kuchotsa filimu ya flux. Kulimba kwa flux komwe kumagwiritsidwa ntchito kumaphatikizapo flux yochokera ku chloride ndi flux yochokera ku fluoride. Kulimba kwa chloride komwe kumachokera ku chloride kuli ndi mphamvu yayikulu yochotsa filimu ya oxide ndi kusinthasintha kwabwino, koma kumakhala ndi mphamvu yayikulu yowononga pa chitsulo choyambira. Zotsalira zake ziyenera kuchotsedwa kwathunthu pambuyo pa kulimba. Kulimba kwa fluoride komwe kumachokera ku fluoride ndi mtundu watsopano wa flux, womwe uli ndi mphamvu yabwino yochotsera filimu ndipo sungathe kuwononga chitsulo choyambira. Komabe, uli ndi malo osungunuka kwambiri komanso kukhazikika kwa kutentha kochepa, ndipo ungagwiritsidwe ntchito kokha ndi solder ya aluminium silicon.
Pakupangira aluminiyamu ndi aluminiyamu, mpweya wa vacuum, wosalowerera kapena wopanda mphamvu umagwiritsidwa ntchito nthawi zambiri. Pakupangira vacuum, mlingo wa vacuum nthawi zambiri uyenera kufika pa 10-3pa. Mukagwiritsa ntchito mpweya wa nayitrogeni kapena argon kuti muteteze, kuyera kwake kuyenera kukhala kokwera kwambiri, ndipo mame ayenera kukhala otsika kuposa -40 ℃.
3. Ukadaulo wa brazing
Kupaka utoto wa aluminiyamu ndi aluminiyamu ndikofunikira kwambiri pakutsuka pamwamba pa workpiece. Kuti mupeze khalidwe labwino, utoto wa mafuta ndi filimu ya oxide pamwamba pake uyenera kuchotsedwa musanapaka utoto. Chotsani utoto wa mafuta pamwamba pake ndi yankho la Na2CO3 lamadzi pa kutentha kwa 60 ~ 70 ℃ kwa mphindi 5 ~ 10, kenako muzimutsuka ndi madzi oyera; Filimu ya oxide pamwamba pake ikhoza kuchotsedwa popaka utoto ndi yankho la NaOH lamadzi pa kutentha kwa 20 ~ 40 ℃ kwa mphindi 2 ~ 4, kenako muzimutsuka ndi madzi otentha; Mukachotsa utoto wa mafuta ndi filimu ya oxide pamwamba pake, workpiece iyenera kutsukidwa ndi yankho la HNO3 lamadzi kuti liume kwa mphindi 2 ~ 5, kenako kutsukidwa m'madzi othamanga ndikuuma pomaliza. Workpiece yokonzedwa ndi njira izi siyenera kukhudzidwa kapena kuipitsidwa ndi dothi lina, ndipo iyenera kutsukidwa mkati mwa maola 6 ~ 8. Ndi bwino kupukuta utoto nthawi yomweyo ngati n'kotheka.
Njira zophikira zitsulo za aluminiyamu ndi aluminiyamu zimaphatikizapo kupiringiza moto, kupiringiza zitsulo zosungunula ndi kupiringiza ng'anjo. Njirazi nthawi zambiri zimagwiritsa ntchito kupiringiza mu kupiringiza, ndipo zimakhala ndi zofunikira kwambiri pa kutentha kwa kutentha ndi nthawi yogwira. Pakupiringiza moto ndi kupiringiza zitsulo zosungunula, pewani kutentha kupiringiza mwachindunji ndi gwero la kutentha kuti kupiringiza kutenthe kwambiri ndi kulephera. Popeza aluminiyamu imatha kusungunuka mu solder yofewa yokhala ndi zinc yambiri, kutentha kuyenera kuyimitsidwa kaye chilumikizocho chikapangidwa kuti chipewe dzimbiri lachitsulo. Nthawi zina, kupiringiza zitsulo za aluminiyamu ndi aluminiyamu nthawi zina sikugwiritsa ntchito kupiringiza, koma kumagwiritsa ntchito njira zamagetsi kapena zokanda kuti muchotse filimuyo. Mukagwiritsa ntchito kupiringiza kuchotsa filimuyo, choyamba tenthetsani chidutswa cha ntchitoyo kutentha kwake, kenako piringizani gawo la kupiringiza la chidutswacho ndi mapeto a ndodo yosungunula (kapena chida chokanda). Mukaswa filimu ya oxide pamwamba, kumapeto kwa solder kudzasungunuka ndikunyowetsa chitsulo choyambira.
Njira zosungira zitsulo za aluminiyamu ndi aluminiyamu makamaka zimaphatikizapo kusungira moto, kusungira ng'anjo, kusungira dip, kusungira vacuum ndi kusungira mpweya wotetezedwa ndi gasi. Kusungira moto kumagwiritsidwa ntchito kwambiri pazinthu zazing'ono komanso kupanga chidutswa chimodzi. Pofuna kupewa kulephera kwa kusuntha chifukwa cha kukhudzana pakati pa zodetsa mu acetylene ndi kusuntha pogwiritsa ntchito lawi la oxyacetylene, ndikofunikira kugwiritsa ntchito lawi la mpweya wopanikizika ndi petulo pang'ono kuti chitsulo choyambira chisawonongeke. Pakusungira chitsulo china, kusuntha kwa chitsulo ndi chitsulo chodzaza zitha kuyikidwa pamalo osungiramo zitsulo pasadakhale ndikutenthedwa nthawi yomweyo ndi chitsulo chogwirira ntchito; Chogwirira ntchitocho chikhozanso kutenthedwa kutentha kwa chitsulo choyamba, kenako chosungunula choviikidwa ndi kusuntha chingatumizidwe pamalo osungiramo zitsulo; Pambuyo poti kusuntha kwa chitsulo ndi chodzaza zisungunuka, lawi lotenthetsera liyenera kuchotsedwa pang'onopang'ono chitsulo chodzaza chikadzazidwa mofanana.
Mukayika aluminiyamu ndi aluminiyamu mu uvuni wa mpweya, chitsulo chodzaza chitsulo chiyenera kukonzedwa kale, ndipo chitsulo chosungunula chiyenera kusungunuka m'madzi osungunuka kuti akonze yankho lokhuthala ndi kuchuluka kwa 50% ~ 75%, kenako nkupakidwa kapena kupopera pamwamba pa chitsulo chosungunula. Kuchuluka koyenera kwa ufa wosungunula kungathenso kuphimbidwa pa chitsulo chosungunula chitsulo ndi pamwamba pa chitsulo chosungunula, kenako weldment yosonkhanitsidwayo iyenera kuyikidwa mu uvuni kuti itenthetse chitsulo. Pofuna kupewa chitsulo choyambira kuti chisatenthe kwambiri kapena kusungunuka, kutentha kwa kutentha kuyenera kulamulidwa mosamala.
Chotsukira cha phala kapena foil nthawi zambiri chimagwiritsidwa ntchito potsukira zitsulo za aluminiyamu ndi aluminiyamu. Chotsukira chosonkhanitsidwacho chiyenera kutenthedwa bwino chisanatsukidwe kuti kutentha kwake kukhale pafupi ndi kutentha kwa chitsulo, kenako nkuviikidwa mu chitsulo chotsukira kuti chitsukidwe. Panthawi yotsukira, kutentha kwa chitsulo ndi nthawi yotsukira ziyenera kulamulidwa mosamala. Ngati kutentha kuli kokwera kwambiri, chitsulo choyambira chimakhala chosavuta kusungunuka ndipo chotsukiracho chimakhala chosavuta kutayika; Ngati kutentha kuli kotsika kwambiri, chotsukiracho sichisungunuka mokwanira, ndipo kuchuluka kwa chitsulo chotsukira kumachepa. Kutentha kwa chitsulo choyambira kuyenera kutsimikiziridwa malinga ndi mtundu ndi kukula kwa chitsulo choyambira, kapangidwe ndi malo osungunuka a chitsulo chodzaza, ndipo nthawi zambiri kumakhala pakati pa kutentha kwa madzi a chitsulo chodzaza ndi kutentha kwa solidus kwa chitsulo choyambira. Nthawi yoviika ya chotsukiracho mu bafa yosambira iyenera kuwonetsetsa kuti chotsukiracho chikhoza kusungunuka ndikuyenda bwino, ndipo nthawi yothandizira siyenera kukhala yayitali kwambiri. Kupanda kutero, chinthu cha silicon mu chotsukiracho chingafalikire mu chitsulo choyambira, zomwe zimapangitsa chitsulo choyambira pafupi ndi msoko kukhala chofooka.
Mu vacuum brazing ya aluminiyamu ndi aluminiyamu, zoyambitsa ntchito zachitsulo nthawi zambiri zimagwiritsidwa ntchito kusintha filimu ya oxide pamwamba pa aluminiyamu ndikuwonetsetsa kuti solder ikunyowa ndi kufalikira. Magnesium ingagwiritsidwe ntchito mwachindunji pa workpiece mu mawonekedwe a tinthu tating'onoting'ono, kapena kulowetsedwa m'dera la brazing mu mawonekedwe a nthunzi, kapena magnesium ikhoza kuwonjezeredwa ku aluminium silicon solder ngati chinthu cha alloy. Pa workpiece yokhala ndi kapangidwe kovuta, kuti zitsimikizire kuti nthunzi ya magnesium ikugwira ntchito bwino pa chitsulo choyambira ndikukweza ubwino wa brazing, njira zotetezera zapafupi nthawi zambiri zimatengedwa, ndiko kuti, workpiece imayikidwa kaye m'bokosi lachitsulo chosapanga dzimbiri (lomwe limadziwika kuti bokosi la processing), kenako nkuyikidwa mu ng'anjo ya vacuum kuti itenthetse brazing. Vacuum Brazed Ma alloy a aluminiyamu ndi aluminiyamu ali ndi malo osalala komanso olumikizana okhuthala, ndipo safunika kutsukidwa pambuyo pa brazing; Komabe, zida za vacuum brazing ndizokwera mtengo, ndipo nthunzi ya magnesium imaipitsa ng'anjo kwambiri, kotero imafunika kutsukidwa ndi kusamalidwa pafupipafupi.
Poika aluminiyamu ndi aluminiyamu mumlengalenga wopanda mpweya kapena wopanda mpweya, choyambitsa magnesium kapena flux chingagwiritsidwe ntchito kuchotsa filimuyo. Choyambitsa magnesium chikagwiritsidwa ntchito kuchotsa filimuyo, kuchuluka kwa magnesium komwe kumafunikira kumakhala kotsika kwambiri kuposa kwa chopangira vacuum brazing. Nthawi zambiri, w (mg) ndi pafupifupi 0.2% ~ 0.5%. Ngati kuchuluka kwa magnesium kuli kokwera, ubwino wa cholumikiziracho umachepa. Njira ya NOCOLOK yopangira pogwiritsa ntchito fluoride flux ndi chitetezo cha nayitrogeni ndi njira yatsopano yomwe yapangidwa mwachangu m'zaka zaposachedwa. Popeza zotsalira za fluoride flux sizimayamwa chinyezi ndipo sizimawononga aluminiyamu, njira yochotsera zotsalira za flux pambuyo pa brazing ingasiyidwe. Pansi pa chitetezo cha nayitrogeni, kuchuluka kochepa kwa fluoride flux kumafunika kuphimbidwa, chitsulo chodzaza chimatha kunyowetsa bwino chitsulo choyambira, ndipo n'zosavuta kupeza zolumikizira zapamwamba kwambiri. Pakadali pano, njira iyi ya NOCOLOK yopangira yagwiritsidwa ntchito popanga radiator ya aluminiyamu ndi zigawo zina.
Pa aluminiyamu ndi aluminiyamu yopangidwa ndi flux kupatula flux ya flux, zotsalira za flux ziyenera kuchotsedwa kwathunthu pambuyo pa brazing. Zotsalira za organic brazing flux ya aluminiyamu zitha kutsukidwa ndi organic solutions monga methanol ndi trichloroethylene, kuchepetsedwa ndi sodium hydroxide aqueous solution, kenako kutsukidwa ndi madzi otentha ndi ozizira. Chloride ndi zotsalira za brazing flux ya aluminiyamu, zomwe zitha kuchotsedwa motsatira njira zotsatirazi; Choyamba, zilowerereni m'madzi otentha pa 60 ~ 80 ℃ kwa mphindi 10, yeretsani mosamala zotsalira pa cholumikizira chopangidwa ndi brashi ndi burashi, ndikuziyeretsa ndi madzi ozizira; Kenako zilowerereni mu 15% nitric acid aqueous solution kwa mphindi 30, kenako muzimutsuka ndi madzi ozizira.
Nthawi yotumizira: Juni-13-2022