Laser Welding Basics
I-laser welding yinkqubo engadibananga efuna ukufikelela kwi-weld zone ukusuka kwelinye icala leenxalenye ezidityanisiweyo.
• I-weld yenziwa njengoko ukukhanya kwelaser kutshisa ngokukhawuleza imathiriyeli-ngokuqhelekileyo ibalwe ngeemilimitha zemizuzwana.
• Kukho iintlobo ezi-3 zeewelds:
– Imo yokuqhuba.
– Imo yokuqhuba/yokungena.
-Ukungena okanye imowudi yomngxuma wesitshixo.
• Imowudi yokuqhuba iwelding yenziwa kuxinaniso lwamandla aphantsi lwenza i-weld nugget engekho nzulu kwaye ibanzi.
• Imo yokuqhuba/yokungena yenzeka kuxinaniso lwamandla oluphakathi, kwaye ibonisa ukungena okungaphezulu kunendlela yokuqhuba.
• I-welding yokungena okanye i-key hole ibonakaliswe ngeewelds ezinzulu ezimxinwa.
-Kule ndlela ukukhanya kwelaser kwenza i-filament ye-vaporized material eyaziwa ngokuba "yi-keyhole" eyandisa kwizinto eziphathekayo kwaye ibonelela nge-conduit yokukhanya kwe-laser ukuba ihanjiswe ngokufanelekileyo kwizinto eziphathekayo.
– Oku kuhanjiswa ngokuthe ngqo kwamandla kwizinto eziphathekayo akuthembeli ekuqhubeni ukufezekisa ukungena, kwaye ngoko kunciphisa ukushisa kwizinto eziphathekayo kunye nokunciphisa indawo echaphazelekayo yokushisa.
Ukuqhuba ukuWelding
• Ukudibanisa kokuqhutywa kuchaza usapho lweenkqubo apho umqa welaser ugxininise kuwo:
– Ukunika uxinano lwamandla ngokolandelelwano lwe-10³ Wmm⁻²
-Idibanisa izinto zokwenza umdibaniso ngaphandle kwe-vaporization ebalulekileyo.
• I-welding yokuqhuba ineendlela ezi-2:
– Ukufudumeza ngqo
– Ukuhanjiswa kwamandla.
Ubushushu ngqo
• Ngexesha lokufudumeza ngokuthe ngqo,
- ukuhamba kobushushu kulawulwa yi-classical thermal conduction ukusuka kumthombo wokushisa ongaphezulu kwaye i-weld yenziwa ngokunyibilika kweengxenye zezinto ezisisiseko.
• Iiwelds zokuqhuba ze-1 zenziwa ekuqaleni koo-1960, kusetyenziswa amandla asezantsi epulsed ruby kunye CO2 iilaser zezihlanganisi zocingo.
• Iiwelds zokuqhuba zingenziwa kuluhlu olubanzi lwesinyithi kunye ne-alloys ngendlela yeengcingo kunye namaphepha amancinci kwiimpawu ezahlukeneyo usebenzisa.
- CO2 , Nd:I-YAG kunye ne-laser diode enemigangatho yamandla ngokomyalelo wamashumi e-watts.
– Ukufudumeza ngokuthe ngqo nge CO2 I-laser beam ingasetyenziselwa i-lap kunye ne-butt welds kwi-polymer sheets.
Ukuhanjiswa kweWelding
• Ukuhanjiswa kwewelding yindlela esebenzayo yokudibanisa iipholima ezisasaza kufutshane nemitha ye-infrared ye-Nd:YAG kunye ne-diode lasers.
• Amandla afunxwa ngeendlela ezintsha zokufunxa ngobuso.
• Ii-Composites zinokudityaniswa ngaphandle kokuba iimpawu ze-thermal ze-matrix kunye nokuqinisa ziyafana.
• Imowudi yothumelo lwamandla ye-welding conduction isetyenziswa ngezinto ezisasaza kufutshane nemitha ye-infrared, ngakumbi iipolima.
• I-inki efunxayo ibekwe kwindawo edibanayo. I-inki ifunxa i-laser beam energy, eyenziwa kubunzima obulinganiselweyo bezinto ezijikelezileyo ukwenza ifilimu edibeneyo etyhidiweyo eqinile njengedibeneyo edibeneyo.
• Imijikelo ejiyileyo inokwenziwa ngaphandle kokunyibilika umphezulu ongaphandle wejoyinti.
• I-butt welds inokwenziwa ngokujolisa amandla kumgca wokudityaniswa nge-engile ngesixhobo kwelinye icala lesihlanganisi, okanye ukusuka kwelinye icala ukuba isixhobo sigqithisela kakhulu.
I-Laser Soldering kunye neBrazing
• Kwiinkqubo ze-laser soldering kunye ne-brazing, i-boam isetyenziselwa ukunyibilikisa ukongezwa kwe-filler, emanzisa imida ye-joint ngaphandle kokunyibilika kwezinto ezisisiseko.
• I-laser soldering yaqala ukufumana ukuthandwa ekuqaleni koo-1980 ngokujoyina iintambo zamacandelo e-elektroniki ngemingxuma kwiibhodi zesekethe eziprintiweyo. Iiparamitha zenkqubo zichongwa yimpahla yezinto eziphathekayo.
Ukungena kweLaser Welding
• Xa uxinaniso lwamandla aphezulu zonke izixhobo ziya kuba ngumphunga ukuba amandla anokufunxwa. Ngaloo ndlela, xa u-welding ngale ndlela umngxuma udla ngokubunjwa ngu-evaporation.
• Lo “mngxuma” uthi ke utyhutywe ngemathiriyeli neendonga ezityhidiweyo zivale emva kwayo.
• Isiphumo yinto eyaziwa ngokuba yi "keyhole weld. Oku kubonakala ngezowuni edityanisiweyo esecaleni enxuseneyo kunye nobubanzi obumxinwa.
Laser Welding Efficiency
• Igama lokuchaza le ngqikelelo yokusebenza ngokufanelekileyo laziwa ngokuba “kukusebenza ngokudibeneyo”.
• Ubuchule bokudibanisa asilobuchule bokwenyani kuba uneeyunithi (mm2 ezidityanisiweyo/kJ zinikezelwe).
– Ubuchule=Vt/P (ukubuyisela amandla athile ekusikeni) apho iV = isantya sokunqumla, mm/s; t = ubukhulu obudityanisiweyo, mm; P = amandla esiganeko, KW.
Ukujoyina ngokuSebenzayo
• Xa liphezulu ixabiso lokudibanisa ngokufanelekileyo amandla amancinci achithwa kubushushu obungeyomfuneko.
– Ubushushu obusezantsi bommandla ochaphazelekayo (HAZ).
- Ukuphazamiseka okuphantsi.
• I-Resistance welding isebenze kakhulu kulo mba kuba udibaniso kunye ne-HAZ amandla iveliswa kuphela kujongano oluphezulu lokumelana ukuze ludityaniswe.
• I-Laser kunye ne-electron beam nazo zisebenza kakuhle kunye nokuxinana kwamandla aphezulu.
Ukwahluka kweNkqubo
• Arc Augmented Laser Welding.
-I-arc esuka kwitotshi ye-TIG efakwe kufuphi ne-laser beam interaction point iya kuzitshixa ngokuzenzekelayo kwindawo eshushu eyenziwe nge-laser.
– Iqondo lobushushu elifunekayo kule nto lijikeleze i-300 ° C ngaphezu kobushushu obujikelezileyo.
– Isiphumo mhlawumbi kukuzinzisa i-arc engazinzanga ngenxa yesantya sayo sokunqumla okanye ukunciphisa ukuchasana kwe-arc ezinzileyo.
- Ukutshixa kwenzeka kuphela kwii-arcs ezinomsinga ophantsi kwaye ngoko ke ijethi ye-cathode ecothayo; oko kukuthi, kwimisinga engaphantsi kwe80A.
-I-arc ikwicala elifanayo le-workpiece njenge-laser evumela ukuphindaphinda kwesantya se-welding ngokunyuka okuthobekileyo kwindleko enkulu.
• I-Twin Beam Laser Welding
- Ukuba i-2 laser beams isetyenziswe ngaxeshanye ke kukho ithuba lokulawula i-weld pool geometry kunye ne-weld bead shape.
-Usebenzisa imiqadi ye-electron emi-2, umngxuma wesitshixo unokuzinziswa ubangela amaza ambalwa kwi-weld pool kwaye unike ukungenwa okungcono kunye nokumila kweentsimbi.
– An excimer kunye CO2 indibaniselwano ye-laser beam ibonise ukudityaniswa okuphuculweyo kokudityaniswa kwezixhobo ezibonisa ukukhanya okuphezulu, njenge-aluminiyam okanye ubhedu inokufumaneka.
-Unxulumano olwandisiweyo lwaqwalaselwa ikakhulu ngenxa yoku:
• Ukuguqula ukubonakaliswa ngokukrazula komphezulu okubangelwa yi-excimer.
• isiphumo sesibini esivela ekudibaneni nge-excimer eyenziwe ngeplasma.
