Txoj kev tshawb no tau muab piv rau cov ntawv thov ntawm cov pa LW, OLW thiab RMOLW ntawm TC4 titanium alloy daim hlau. Cov kev tshawb fawb tau siv ntau txoj hauv kev xws li siab - lub koob yees duab ceev, kho qhov muag microscopy (OM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) thiab tensile testing. Cov txiaj ntsig tau pom tias cov txheej txheem RMOLW txhim kho qhov tsim ntawm qhov zoo ntawm cov vuam, tsis yog tsuas yog tshem tawm qhov tsis xws luag, tab sis kuj txo qis kev tawg. Mechanistically, lub annular beam nthuav dav qhov qhib qhov qhib qhov chaw (txog 0.76 mm²), thiab cov vortices ruaj khov tsim los ntawm cov nqaj oscillation zoo tiv thaiv lub qhov tseem ceeb ntawm kev kaw vim yog cov hlau molten compression, yog li txiav tawm qhov chaw ntawm spatter. Hais txog microstructure, cov txheej txheem no txo qhov kub thiab txias ntawm lub pas dej molten, txhawb kev tsim cov pob tawb zoo -weave morphology hauv qhov chaw weld thiab nce qhov feem ntawm siab -angle grain ciam teb (HAGB). Thaum kawg, RMOLW welded pob qij txha tuav lub zog tensile siab (nyob ib ncig ntawm 1148.8 MPa), thaum lub elongation yog nce los ntawm 35.2% piv nrog cov pa laser welding, ua tau zoo match ntawm lub zog thiab ductility.
Daim duab 1 qhia txog kev sim teeb tsa ntawm RMOLW. Cov tub ntxhais yog nyob rau hauv kev siv tshwj xeeb annular optical fibers, ua ib tug sib xyaw beam uas muaj ib tug central fiber core (100 µm) thiab ib lub nplhaib sab nraud fiber core (300 µm). Lub beam tsis tsuas yog muaj lub zog faib hluav taws xob nkaus xwb tab sis kuj ua rau lub voj voog (kauv) oscillation trajectory los ntawm galvanometer system. Qhov kev tsim no tsom mus rau ib txhij siv "qhov- nthuav dav" cuam tshuam ntawm cov kab hluav taws xob annular thiab "stirring" nyhuv ntawm oscillation.
Daim duab 1. Schematic daim duab ntawm lub nplhaib- hom oscillating laser welding ntaus ntawv: (a) integrated sim khoom (b) fiber ntau cross-section, core txoj kab uas hla thiab focal point loj (c) tiag tiag trajectory ntawm lub laser beam.
Daim duab 2 qhia tau hais tias LW nto ntug yog wavy, nrog rau ib tug loj npaum li cas ntawm spatter, nrog ib tug ntoo khaub lig-section nyob rau hauv ib tug 'X' puab thiab qhov siab tshaj plaws undercut qhov tob. RMOLW weld ntug yog ncaj thiab du, yuav luag tsis muaj spatter, dav 'V'-zoo li tus ntoo khaub lig-section, qis qis qis qis, thiab kev hloov pauv. Qhov no qhia tau hais tias lub zog faib ntawm RMOLW yog ib qho zoo sib xws, txhim kho cov txheej txheem vuam zoo.
Daim duab 2. Macroscopic morphology thiab cross-sectional morphology ntawm cov pob qij txha: (a, d, g) vuam morphology ntawm laser vuam qauv, (b, e, h) vuam morphology ntawm oscillating laser welding qauv, (c, f, i) vuam morphology ntawm vuam qauv oscilling
Daim duab 3. Molten pas dej ua ke thiab keyhole qhib tus cwj pwm nyob rau hauv cov txheej txheem sib txawv: (a) tiam ntawm spatter thaum lub sij hawm laser vuam (b) tshwm sim ntawm oscillating laser vuam nyob rau hauv ib lub voj voog (c) tshwm sim ntawm oscillating laser welding nrog ib tug annular chaw qauv nyob rau hauv ib lub voj voog. Daim duab 4 qhia tau hais tias LW muaj lub zog siab tshaj plaws ntawm Gaussian kev faib tawm, nrog lub zog siab heev ntawm qhov chaw (407.2 J / mm²), ua rau lub pas dej nqaim thiab sib sib zog nqus. RMOLW nthuav tawm ib qho "flat-} sab saum toj" cov hluav taws xob faib hluav taws xob (qhov siab tshaj plaws tsuas yog 107.6 J / mm²), nrog rau qhov sib xws ntawm lub zog faib tau nce 2.2 npaug. Cov cua kub sib xws no txo qis qis, ua rau cov hlaws hla-section wider thiab smoother.
Txoj kev tshawb no, los ntawm kev sib piv ntawm LW, OLW thiab RMOLW cov txheej txheem, tau mus txog cov ntsiab lus tseem ceeb hauv qab no: 1. RMOLW tiv thaiv keyhole vau los ntawm kev nthuav dav lub qhov qhib qhov qhib rau 0.76 mm² thiab qhia txog qhov ruaj khov vortex, txo spatter thaum lub sij hawm vuam los ntawm 88.6% piv nrog cov pa roj carbon monoxide {RMOL4 RMW} cov txheej txheem zoo dua qub 20 lub sij hawm, tshem tawm cov cua sov hauv zos, txo cov vuam undercut qhov tob los ntawm 56.3%, thiab tsim V-zoo li tus ntoo khaub lig-section. 3. Kev sib koom ua ke ntawm cov kab hluav taws xob annular thiab oscillation txo qhov kub ntawm gradients thiab txias tus nqi nyob rau hauv lub pas dej ua ke molten, txhawb kev tsim ntawm 1}} cov qauv siab 0.76 thiab cov txheej txheem siab 0.76 lamellar alpha theem, thiab txo cov concentration ntawm grain orientation . 4. Ua tsaug rau kev tiv thaiv ntawm undercut defects thiab lub zog ntawm microstructure (ntau dua -angle grain ciam teb), lub elongation ntawm RMOLW pob qij txha yog nce los ntawm 35.2% piv nrog cov pa laser welding, thaum tuav lub zog tensile zog.
