5 Feem ntau Laser Welding Defects: Ua thiab Tiv Thaiv Cov Tswv Yim

Apr 14, 2022 Tso lus

Laser vuam tau dhau los ua lub hauv paus ntawm kev tsim khoom niaj hnub no vim nws qhov kev ua haujlwm siab, tshwj xeeb precision, huv tiav, thiab seamless automation muaj peev xwm. Nws ua lub luag haujlwm tseem ceeb thoob plaws ntau qhov kev xav tau, suav nrog aerospace, automotive parts (3C), cov khoom siv kho mob, cov ntawv hlau tsim, thiab lub zog ntsuab.

 

Txawm li cas los xij, zoo li cov txheej txheem tsim khoom siab heev, kev ua tiav cov txiaj ntsig tsis zoo yuav tsum muaj kev nkag siab tob txog nws cov ntsiab lus tseem ceeb thiab tsis muaj. Kev teeb tsa tsis raug tuaj yeem ua rau muaj qhov tsis zoo ntawm cov qauv lossis cov tshuaj pleev ib ce. Los ntawm kev nkag siab tias vim li cas cov kev tsis zoo no tshwm sim, koj tuaj yeem ua kom zoo dua koj cov kev teeb tsa tau yooj yim kom xa cov qib siab - zoo, siab - lub zog welds.

 

Raws li kev paub dhau los xyoo dhau los, peb cov engineers tau sau cov lus qhia txog kev daws teeb meem rau 5 feem ntau cov teeb meem laser vuam.

 

1. Cracks (Thermal & solidification Cracks)

Thaum lub sij hawm txuas ntxiv laser welding, cov teeb meem tshwm sim feem ntau yog kub tawg, nrog rau kev ua kom khov (crystallization) tawg thiab liquefaction tawg.

 

Qhov laj thawj:Cov kab nrib pleb no tshwm sim thaum lub zog tensile hnyav loj tuaj raws li lub pas dej welds shrinks sai ua ntej cov hlau molten tau tag nrho solidified.

 

Close-up of a centerline crystallization crack in a laser continuous weld bead, showing solidification separation

 

Kev daws:

  • Siv Filler Wire:Qhia txog kev sib txuas vuam hlau tuaj yeem kho cov tshuaj muaj pes tsawg leeg ntawm lub pas dej welding thiab txo qis kev ntxhov siab.
  • Preheating:Preheating lub hauv paus hlau txo cov cua txias, txo qhov seem ntawm thermal stress.

 

2. Porosity (Blowholes)

Porosity yog ib qho ntawm cov teeb meem nquag tshaj plaws hauv laser vuam, feem ntau cuam tshuam rau ob qho tib si kev ncaj ncees thiab cov tsos ntawm kev sib koom ua ke.

 

Qhov laj thawj:Laser vuam tsim lub pas dej sib sib zog nqus, nqaim molten uas txias thiab khov ntawm tus nqi nrawm heev. Gases nyob rau hauv lub pas dej ua kua feem ntau tsis muaj sij hawm txaus los khiav ua ntej cov hlau khov.

Cross-section view of subsurface blowholes and fine porosity trapped within a laser-welded joint

 

Kev daws:

  • Kev npaj nto:Ua tib zoo ntxuav qhov chaw ua haujlwm ua ntej vuam kom tshem tawm cov roj, noo noo, thiab oxide txheej uas tsim cov roj.
  • Optimize Shielding Gas:Kho tus nqi ntws thiab tshuab lub kaum sab xis ntawm koj cov roj thaiv kev tiv thaiv kom zoo tiv thaiv thaj tsam weld yam tsis ua rau muaj kev kub ntxhov.

 

3. Spatter

Kev sib tsoo ntau dhau tsis tsuas yog rhuav tshem qhov kawg ntawm lub vuam, tab sis kuj tuaj yeem ua paug lossis puas tsuaj rau kev tiv thaiv optics ntawm koj lub taub hau laser vuam.

 

Qhov laj thawj:Spatter yog ncaj qha tshwm sim los ntawm lub zog ntau dhau. Thaum lub zog tawm tswv yim siab dhau lawm, lub vapor siab nyob rau hauv lub qhov tseem ceeb destabilizes molten pas dej ua ke, hnyav ejecting droplets ntawm kua hlau.

 

Excessive molten metal spatter during deep penetration laser welding, contaminating the workpiece surface

 

Kev daws:

  • Tsawg zog ceev:Txo lub zog laser los yog me ntsis defocus lub beam kom stabilize lub pas dej ua ke.
  • Tshuav Ceev:Yog tias qhov txo qis hauv lub zog ua rau muaj kev nkag mus tsis txaus, txo qis kev mus los raws li kev tswj hwm lub zog ruaj khov.

 

4. Txom nyem

Ib qho undercut tshwm raws li ib tug zawj los yog kev nyuaj siab nyob rau hauv cov npoo ntawm lub weld hlaws, tsis muaj zog cov neeg kho tshuab lub zog ntawm kev sib koom tes.

 

Qhov laj thawj:Qhov no feem ntau tshwm sim thaum lub sij hawm mus txawv tebchaws ceev heev, tawm hauv lub molten hlau tsis txaus lub sij hawm rau reflow thiab smoothly sau ob sab ntawm lub weld sib koom tes. Tsis tas li ntawd, kev sib koom ua ke ntau dhau los yog lub zog poob sai sai - tawm ntawm qhov kawg ntawm txoj kev sib txuas (ua rau lub qhov tseem ceeb kom tawg) yuav ua rau muaj kev cuam tshuam hauv cheeb tsam.

 

Optical microscope image of an undercut defect, showing a groove formed along the edge of a laser weld bead

 

Kev daws:

  • Optimize Power-rau-Speed ​​Ratio:Xyuas kom koj qhov kev mus ncig ceev tso cai rau kev rov ua kom zoo dua qub thiab ruaj khov.
  • Tighten Tolerances:Txo qhov haum- nce qhov sib txawv thaum lub sijhawm ua haujlwm ua ke.
  • Lub zog ramping:Ua kom lub zog ua kom qis dua- nqes (qhov dej nyab- ua haujlwm puv) ntawm qhov kev txiav tawm ntawm qhov vuam kom tiv thaiv lub qhov tseem ceeb.

 

5. Weld Sag (Collapse & Sink)

Weld sag lossis sinkage yog hais txog kev nyuaj siab nyob rau hauv nruab nrab ntawm cov hlaws dai, feem ntau ua rau lub hauv paus convex thiab lub ntsej muag underfilled.

 

Qhov laj thawj:Thaum lub vuam ceev qeeb dhau lawm, cov cua kub nkag ua ntau dhau. Qhov no tsim ib lub pas dej loj loj uas qhov hnyav ntawm cov kua hlau overrides nws qhov nro, ua rau qhov nruab nrab ntawm cov weld rau tog los yog sag.

 

Weld sag and sinkage defect in an aluminum alloy, featuring a depressed weld face and concave center

 

Kev daws:

  • Txo cov cua kub nkag:Txo lub zog laser los yog ua kom lub vuam ceev kom txo tau lub pas dej molten loj.
  • Tswj zog ceev:Keep the energy density within a range that allows surface tension to successfully hold the molten metal in place.

 

Kev cia siab thiab paub txog cov kev tsis txaus ntseeg no yog thawj kauj ruam mus rau kev ua tiav xoom- tsis xws luaglaser vuam. Los ntawm kev saib xyuas tsis tu ncua thiab ua kom zoo-tu koj lub laser tsis, koj tuaj yeem qhib tag nrho cov peev txheej ntawm koj cov cuab yeej thiab xa cov khoom siv tsis tu ncua, siab - lub zog muaj zog.