I-Laser Welding Basics
I-laser welding iyinqubo engathintana nayo edinga ukufinyelela endaweni yokushisela ukusuka ohlangothini olulodwa lwezingxenye ezishiselwe.
• I-weld yakheka njengoba ukukhanya kwe-laser okunamandla kushisa ngokushesha okubalulekile-okuvame ukubalwa ngama-milli-amasekhondi.
• Kunezinhlobo ezi-3 zokushisela:
– Imodi yokuqhuba.
– Imodi yokuqhuba/yokungena.
- Imodi yokungena noma yembobo kakhiye.
• Ukushisela kwemodi yokuqhuba kwenziwa lapho kuningi kakhulu amandla okwenza i-weld nugget engashoni futhi ebanzi.
• Imodi yokuqhuba/ukungena yenzeka kumandla aphakathi nendawo, futhi ikhombisa ukungena kakhulu kunemodi yokuqhuba.
• Imodi yokungena noma yembobo kakhiye ibonakala ngokushisela okuncane okujulile.
- Kule modi isibani se-laser sakha umcu wempahla ehwamukayo eyaziwa ngokuthi "imbobo yokhiye" enwebela kumpahla futhi inikeze umsele ukuze ukukhanya kwe-laser kulethwe ngempumelelo endabeni.
– Lokhu kulethwa kwamandla okuqondile kokubalulekile akuncikile ekuqhubeni ukuze kuzuzwe ukungena, ngakho-ke kunciphisa ukushisa kokubalulekile futhi kunciphisa indawo ethintekile ekushiseni.
I-Welding yokuqhuba
• Ukujoyina i-conduction kuchaza umndeni wezinqubo lapho i-laser beam igxile khona:
– Ukunikeza ukuminyana kwamandla nge-oda lika-10³ Wmm⁻²
- Ihlanganisa izinto zokwakha ilunga ngaphandle kokuhwamuka okukhulu.
• I-Conduction welding inezindlela ezi-2:
– Ukushisisa Direct
- Ukudluliselwa kwamandla.
Ukushisa Okuqondile
• Ngesikhathi sokushisa okuqondile,
- ukugeleza kokushisa kulawulwa yi-classical thermal conduction evela emthonjeni wokushisa ongaphezulu futhi i-weld yenziwa ngokuncibilika izingxenye zezinto eziyisisekelo.
• I-1st conduction welds yenziwa ekuqaleni kwawo-1960, yasetshenziswa amandla aphansi e-pulsed ruby futhi CO2 ama-laser wezixhumi zezintambo.
• Ukushisela okuqhutshwayo kungenziwa ezinhlobonhlobo zezinsimbi nama-alloys ngendlela yezintambo namashidi amancane ekucushweni okuhlukahlukene kusetshenziswa.
- CO2 , Nd:YAG namalaser e-diode anamazinga wamandla ngokulandelana kwamashumi ama-watts.
– Ukushisisa Direct by a CO2 i-laser beam ingasetshenziselwa ukushisela i-lap kanye ne-butt kumashidi e-polymer.
I-Transmission Welding
• I-Transmission welding iyindlela ephumelelayo yokuhlanganisa ama-polymer adlulisa imisebe eseduze ye-infrared ye-Nd:YAG namalaser e-diode.
• Amandla amuncwa ngezindlela ezinoveli zokumunca ubuso obuhlangene.
• Izinhlanganisela zingahlanganiswa inqobo nje uma izici ezishisayo ze-matrix nokuqiniswa ziyafana.
• Imodi yokudlulisa amandla ye-conduction welding isetshenziswa nezinto ezidlulisa eduze kwemisebe ye-infrared, ikakhulukazi ama-polymer.
• Uyinki odonsayo ubekwa endaweni ehlangene yethanga. Uyinki udonsa amandla e-laser beam, aqhutshwa abe ugqinsi olulinganiselwe lwento ezungezile ukuze kwakhe ifilimu elincibilikisiwe elihlangana nobuso eliqina njengelunga elishiselwe.
• Amajoyinti aminyene angenziwa ngaphandle kokuncibilika ngaphandle kwelunga.
• Ukushisela izinqe kungenziwa ngokuqondisa amandla emgqeni ohlanganyelwe nge-engeli ngokusebenzisa into ehlangothini olulodwa lwelunga, noma ukusuka kwenye indawo uma impahla idlulisa kakhulu.
I-Laser Soldering ne-Brazing
• Ezinkambisweni ze-laser soldering kanye ne-brazing, i-beam isetshenziselwa ukuncibilikisa isengezo sokugcwalisa, esimanzisa imiphetho ye-joint ngaphandle kokuncibilika kwesisekelo.
• I-laser soldering yaqala ukuthola ukuduma ekuqaleni kwawo-1980 ngokujoyina imikhondo yezingxenye ze-electronic ngokusebenzisa izimbobo kumabhodi esekethe aphrintiwe. Imingcele yenqubo inqunywa izakhiwo ezibonakalayo.
Ukungena Laser Welding
• Uma amandla aminyana aphezulu zonke izinto zizohwamuka uma amandla angamuncwa. Ngakho, lapho welding ngale ndlela imbobo ngokuvamile kwakhiwa ukuhwamuka.
• Le "mbobo" ibe isidatshulwa ngempahla izindonga ezincibilikisiwe zivale ngemuva kwayo.
• Umphumela uba yilokho okwaziwa ngokuthi "i-keyhole weld. Lokhu kubonakala ngendawo yayo yokuhlanganisa esemaceleni ehambisanayo kanye nobubanzi obuncane.
I-Laser Welding Efficiency
• Itemu lokuchaza lo mqondo wokusebenza kahle laziwa ngokuthi "ukusebenza ngokuhlanganyela".
• Ukusebenza kahle kokuhlanganisa akukona ukusebenza kahle kweqiniso ngoba kunamayunithi (mm2 ahlanganisiwe/kJ anikeziwe).
– Ukusebenza kahle=Vt/P (ukuphindaphinda kwamandla athile ekusikeni) lapho V = isivinini sokunqamula, mm/s; t = ukujiya okushiselwe, mm; P = amandla esigameko, KW.
Ukujoyina Ngempumelelo
• Uma liphezulu inani lempumelelo yokuhlanganisa amandla amancane asetshenziswa ekushisiseni okungadingekile.
- Indawo ethintekile ekushiseni okuphansi (HAZ).
- Ukuhlanekezela okuphansi.
• I-Resistance welding iphumelela kakhulu kulokhu ngoba amandla ahlanganisiwe kanye ne-HAZ akhiqizwa kuphela endaweni esebenza kuyo ukumelana nokushiselwa ukuze ishiselwe.
• I-laser ne-electron beam nakho kunokusebenza kahle nokuminyana kwamandla aphezulu.
Izinguquko Zenqubo
• I-Arc Augmented Laser Welding.
- I-arc evela kuthoshi ye-TIG ebekwe eduze nendawo yokuhlangana ye-laser izokhiya ngokuzenzakalelayo endaweni eshisayo ekhiqizwe nge-laser.
– Izinga lokushisa elidingekayo kulesi simo licishe libe ngu-300°C ngaphezu kwezinga lokushisa elizungezile.
– Umphumela uwukusimamisa i-arc engazinzile ngenxa yejubane layo lokunqamula noma ukunciphisa ukumelana kwe-arc ezinzile.
- Ukukhiya kwenzeka kuphela kuma-arcs anejethi le-cathode yamanje ephansi futhi ngenxa yalokho; okungukuthi, imisinga engaphansi kuka-80A.
- I-arc isohlangothini olufanayo lwe-workpiece njenge-laser evumela ukuphindwa kabili kwejubane lokushisela ukuze kukhuphuke kancane izindleko zemali.
• I-Twin Beam Laser Welding
- Uma kusetshenziswa imishayo ye-laser emi-2 ngesikhathi esisodwa khona-ke kukhona ithuba lokulawula i-weld pool geometry kanye nokuma kwe-weld bead.
- Ngokusebenzisa imishayo yama-electron angu-2, imbobo kakhiye ingasimama ibangele amagagasi ambalwa echibini lokushisela futhi inikeze ukungena okungcono nokuma kobuhlalu.
- I-excimer kanye CO2 Inhlanganisela ye-laser beam ibonise ukuhlangana okuthuthukisiwe kokushiselwa kwezinto ezibonisa ukukhanya okuphezulu, njenge-aluminium noma ithusi kungatholakala.
- Ukuhlanganisa okuthuthukisiwe kucatshangelwe ngokuyinhloko ngenxa yokuthi:
• ukushintsha ukubonakala ngokugedlezela okubangelwa i-excimer.
• umphumela wesibili ovela ekuhlanganeni nge-plasma ekhiqiziwe ye-excimer.
