Kuwotcherera ndi laser ndi chimodzi mwazinthu zofunika kwambiri pakugwiritsa ntchito ukadaulo wokonza laser, komanso ukadaulo wowotcherera wokopa kwambiri komanso wodalirika m'zaka za m'ma 2000. Poyerekeza ndi njira zachikhalidwe zowotcherera, kuwotcherera ndi laser kuli ndi zabwino zambiri, mtundu wapamwamba wowotcherera komanso magwiridwe antchito mwachangu. Pakadali pano, ukadaulo wowotcherera ndi laser wakhala ukugwiritsidwa ntchito kwambiri popanga zinthu, kupanga zitsulo za ufa, makampani opanga magalimoto, makampani amagetsi, biomedicine ndi madera ena.
Malinga ndi njira yopangira dziwe lopachikira zitsulo, kuwotcherera kwa laser kuli ndi njira ziwiri zazikulu zowotcherera: kuwotcherera kutentha ndi kuwotcherera mozama (dzenje laling'ono). Kutentha komwe kumapangidwa ndi kuwotcherera kutentha kumafalikira ku workpiece kudzera mu kusamutsa kutentha, kotero kuti pamwamba pa weld imasungunuka, kwenikweni palibe chochitika cha nthunzi, chomwe nthawi zambiri chimagwiritsidwa ntchito powotcherera zinthu zotsika liwiro lochepa. Kuwotcherera kozama kumatenthetsa zinthuzo ndikupanga plasma yambiri. Chifukwa cha kutentha kwakukulu, padzakhala mabowo kutsogolo kwa dziwe losungunuka. Kuwotcherera kozama kumatha kuwotcherera bwino workpiece, ndipo mphamvu yolowera ndi yayikulu, liwiro lowotcherera ndi lachangu, ndipo ndiyo njira yowotcherera ya laser yomwe imagwiritsidwa ntchito kwambiri.
Pali zinthu zambiri zomwe zimakhudza ubwino wa welding ya laser, monga kuchuluka kwa mphamvu, mawonekedwe a mafunde a laser, defocus, liwiro la welding ndi mpweya wothandiza wopukutira.
1. Kuchuluka kwa mphamvu ya laser Kuchuluka kwa mphamvu ndi chimodzi mwa zinthu zofunika kwambiri pakupanga laser. Ndi mphamvu yochulukirapo, gawo la pamwamba limatha kutenthedwa mpaka kufika powira mkati mwa nthawi ya microsecond, zomwe zimapangitsa kuti mpweya ukhale wambiri. Chifukwa chake, mphamvu yochuluka ndi yabwino kwambiri pochotsa zinthu, monga kuboola, kudula ndi kulemba. Kuti mphamvu yocheperako ikhale yochepa, pamafunika ma millisecond angapo kuti kutentha kwa pamwamba kufikire powira, ndipo gawo la pamwamba lisanatenthe, gawo la pansi lifike posungunuka, zomwe zimakhala zosavuta kupanga welding yabwino yosakanikirana. Chifukwa chake, mu welding ya laser yoyendetsa kutentha, kuchuluka kwa mphamvu ndi 104-106W/cm2.
2. Mafunde a laser pulse
Mafunde a laser pulse si chinthu chofunikira kwambiri chosiyanitsa kuchotsa zinthu kuchokera ku kusungunuka kwa zinthu, komanso ndi chinthu chofunikira kwambiri chodziwira kuchuluka ndi mtengo wa zida zokonzera. Pamene kuwala kwa laser kwamphamvu kwambiri pamwamba pa zinthuzo, pamwamba pa zinthuzo padzakhala ndi 60 ~ 90% ya kuwunikira ndi kutayika kwa mphamvu ya laser, makamaka golide, siliva, mkuwa, aluminiyamu, titaniyamu ndi zinthu zina kuwunikira kwamphamvu, kusamutsa kutentha mwachangu. Kuwunikira kwa chitsulo kumasiyana ndi nthawi panthawi ya chizindikiro cha laser pulse. Pamene kutentha kwa pamwamba pa zinthuzo kwakwezedwa kufika pamalo osungunuka, kuwunikira kumachepa mofulumira, ndipo pamene pamwamba pake pali kusungunuka, kuwunikirako kumakhazikika pamtengo winawake.
3. Kuchuluka kwa ma pulse Kuchuluka kwa ma pulse ndi gawo lofunika kwambiri la pulsed laser welding. Kuchuluka kwa ma pulse kunatsimikiziridwa ndi kuzama kwa kulowa ndi dera lomwe lakhudzidwa ndi kutentha. Kutalika kwa ma pulse, kukulira kwa dera lomwe lakhudzidwa ndi kutentha, komanso kuzama kwa kulowa kumawonjezeka ndi 1/2 mphamvu ya pulse width. Komabe, kuwonjezeka kwa pulse width kudzachepetsa mphamvu ya peak, kotero kuwonjezeka kwa pulse width nthawi zambiri kumagwiritsidwa ntchito powotcherera kutentha, zomwe zimapangitsa kuti pakhale weld yayikulu komanso yosaya, makamaka yoyenera kuwotcherera lap plates zoonda komanso zokhuthala. Komabe, mphamvu yochepa ya peak imabweretsa kutentha kwambiri, ndipo chinthu chilichonse chili ndi pulse width yabwino kwambiri yomwe imakulitsa kulowa.
4, kulowetsa laser defocus nthawi zambiri kumafuna kuchuluka kwa defocus, chifukwa laser focus pakati pa spot power density ndi yayikulu kwambiri, yosavuta kusungunuka m'mabowo. Kugawa kwa mphamvu yamagetsi kumakhala kofanana mu ndege iliyonse kutali ndi laser focus. Pali njira ziwiri zochotsera focus: positive defocus ndi negative defocus. Ngati focal plane ili pamwamba pa workpiece, ndi positive defocus; apo ayi, ndi negative defocus. Malinga ndi chiphunzitso cha geometrical optics, pamene mtunda pakati pa ndege zabwino ndi zoipa defocus ndi welding plane uli wofanana, mphamvu yamagetsi pa ndege yofanana ndi yofanana, koma mawonekedwe enieni a weld pool omwe apezeka ndi osiyana. Pankhani ya negative defocus, kulowa kwakukulu kungapezeke, komwe kumakhudzana ndi njira yopangira dziwe losungunuka.
5, liwiro lowotcherera Liwiro lowotcherera limatsimikiza mtundu wa pamwamba pa kuwotcherera, kulowa mkati, malo omwe akhudzidwa ndi kutentha, ndi zina zotero. Liwiro la kuwotcherera lidzakhudza momwe kutentha kumalowera pa nthawi iliyonse. Ngati liwiro lowotcherera lili pang'onopang'ono kwambiri, kutentha kumakhala kwakukulu kwambiri, zomwe zimapangitsa kuti workpiece ipse. Ngati liwiro lowotcherera lili mofulumira kwambiri, kutentha kumakhala kochepa kwambiri, zomwe zimapangitsa kuti workpiece isamawoneke bwino. Kuchepetsa liwiro lowotcherera nthawi zambiri kumagwiritsidwa ntchito kuti kulowetse bwino.
6, mpweya woteteza mpweya wothandizira ndi njira yofunika kwambiri pakuwotcherera ndi laser yamphamvu kwambiri. Kumbali imodzi, kupewa kuti zitsulo zisatuluke ndikuipitsa galasi loyang'ana; Kumbali ina, ndikuletsa plasma yopangidwa mu ndondomeko yowotcherera kuti isayang'ane kwambiri ndikuletsa laser kufika pamwamba pa zinthuzo. Mu njira yowotcherera ndi laser, helium, argon, nayitrogeni ndi mpweya wina nthawi zambiri amagwiritsidwa ntchito kuteteza dziwe losungunuka, kuti ntchitoyo itetezedwe ku okosijeni muukadaulo wowotcherera. Zinthu monga mtundu wa mpweya woteteza, kukula kwa mpweya ndi ngodya yowotcherera zimakhudza kwambiri zotsatira za kuwotcherera. Njira zosiyanasiyana zowotcherera nazonso zimakhudza mtundu wa kuwotcherera.
Helium siimapanga ma ioni mosavuta (ili ndi mphamvu zambiri zopanga ma ioni), zomwe zimathandiza kuti laser idutse bwino komanso mphamvu ya kuwala ifike pamwamba pa workpiece popanda choletsa. Uwu ndiye mpweya woteteza kwambiri womwe umagwiritsidwa ntchito pokonza ma laser, koma mtengo wake ndi wokwera mtengo. Argon ndi yotsika mtengo komanso yokhuthala, kotero ili ndi chitetezo chabwino. Komabe, imapangidwa mosavuta ndi plasma yachitsulo yotentha kwambiri, motero imateteza gawo la mtanda ku workpiece, kuchepetsa mphamvu yogwira ntchito ya laser yokonza ma welding, komanso kuwononga liwiro la welding ndi kulowa mkati. Malo a welds otetezedwa ndi argon ndi osalala kuposa omwe amatetezedwa ndi helium. Nayitrogeni ndi mpweya wotsika mtengo kwambiri ngati woteteza, koma siwoyenera mitundu ina ya welding yachitsulo chosapanga dzimbiri, makamaka chifukwa cha mavuto a zitsulo, monga kuyamwa, komwe nthawi zina kumapanga ma pores m'dera la lap.
Monga ukadaulo watsopano wowotcherera, kuwotcherera kwa laser kumakhala ndi mphamvu zambiri, liwiro lalikulu, kulondola kwambiri, kulowa mozama komanso kusinthasintha kwamphamvu. Kugwiritsa ntchito kwake kumakhala kwakukulu, komwe sikungowonjezera luso lopanga, komanso kupititsa patsogolo khalidwe la kuwotcherera. Ukadaulo wowotcherera wa laser udzakhala ndi gawo lofunikira kwambiri pakupanga zinthu.
Nthawi yotumizira: Mar-28-2023
