Optimization of Gap Bridging Performance in Laser Butt Welding Using Beam Shaping Technology: Exploring the Application of Beam Shaping in Mass-Production
Translated title
Optimization of Gap Bridging Performance in Laser Butt Welding Using Beam Shaping Technology
Author
Yin, Wei
Term
4. term
Education
Publication year
2025
Submitted on
2025-05-30
Pages
63
Abstract
Autogenous laser butt welding—joining two edges with a laser without adding filler metal—offers high precision, low heat input, and high efficiency. In practice, small variations in the gap between parts can reduce weld quality. A common way to control gaps is to use high-precision fixtures, but these are expensive, time-consuming to set up, and limit production flexibility. An alternative is beam shaping, which adjusts how laser energy is distributed on the workpiece. There are two main strategies. Dynamic beam shaping uses high-speed scanning to move the beam pattern during welding; it is flexible but costly and, at low scanning frequencies, can destabilize the melt pool. Static beam shaping uses diffractive optical elements (DOEs) to create a fixed pattern; it is cost-effective for large-scale production and easy to maintain, but it cannot readily adapt to different tasks. This study applies, for the first time, quasi-static beam shaping with a Civan laser to design customized beam patterns for welding. The performance of these patterns will be compared with a conventional Gaussian beam (the standard round intensity distribution). Where possible, high-speed and thermal imaging will be used to analyze melt pool behavior. The goal is to identify an optimal beam pattern and provide practical design guidance for static beam shaping methods, especially DOE-based solutions.
Autogen laserstumpsvejsning—at sammenføje to kanter med laser uden tilsatsmateriale—giver høj præcision, lav varmeindføring og høj effektivitet. I praksis kan små variationer i samlingsspalten forringe svejsekvaliteten. En udbredt løsning er at bruge opspændingsfiksturer med høj præcision, men de er dyre, tidskrævende at indstille og begrænser fleksibiliteten i produktionen. En alternativ metode er stråleformning, hvor energifordelingen i laserstrålen tilpasses emnet. Der findes to hovedstrategier. Dynamisk stråleformning bruger højhastighedsskanning til at flytte strålemønsteret under svejsning; den er fleksibel, men dyr og kan ved lave skannefrekvenser gøre smeltebadet ustabilt. Statisk stråleformning bruger diffraktive optiske elementer (DOE'er) til at skabe et fast mønster; den er omkostningseffektiv ved store serier og let at vedligeholde, men kan ikke nemt tilpasses forskellige opgaver. I dette studie anvendes for første gang kvasi-statisk stråleformning med en Civan-laser til at designe skræddersyede strålemønstre til svejsning. Effekten af disse mønstre sammenlignes med en konventionel gaussisk stråle (den klassiske runde intensitetsfordeling). Hvor det er muligt, anvendes højhastigheds- og termisk billeddannelse til at analysere smeltebadets adfærd. Målet er at finde et optimalt strålemønster og give praktiske designindsigter for statiske stråleformningsmetoder, især DOE-baserede løsninger.
[This apstract has been rewritten with the help of AI based on the project's original abstract]
Keywords