Parametric analysis of the pulsed Nd:YAG laser seam-welding process

This paper focuses on the interfacial characteristics of dissimilar Ti6Al4V/AA6060 lap joint produced by pulsed Nd:YAG laser beam welding. The process-sensitivity analysis of welding-induced interface joining quality was performed by using the orthogonal design method. Microstructural tests such as scanning electron microscopy and energy dispersive X-ray spectroscopy were used to observe the interfacial characteristics. The mechanism of interfacial crack initiation, which is an important indicator of joint property and performance, was assessed and analyzed. The preferred propagation paths of welding cracks along the interfaces of different intermetallic layers with high dislocation density were analyzed and discussed in-depth. The results indicate that discontinuous potential phases in the micro-crack tip would mitigate the mechanical resistance or performance of the welded joint, while the continuous intermetallic layer can lead to a sound jointing performance under pulsed Nd:YAG laser welding process.

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The Influence of Welding Parameters on Heat Transfer Efficiency of Hybrid Pulsed Nd: YAG/GTAW Welding

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1088.807 ◽

2015 ◽

Vol 1088 ◽

pp. 807-813

Author(s):

Miao Xia Xie ◽

Lin Jie Zhang

Keyword(s):

Heat Transfer ◽

Nd:Yag Laser ◽

Welding Process ◽

Transfer Efficiency ◽

304 Stainless Steel ◽

Welding Parameters ◽

Hybrid Welding ◽

Pulsed Nd:Yag Laser ◽

Heat Transfer Efficiency ◽

Cross Section Area

In this work, effects of major welding parameters, such as laser power, defocus distance of laser beam, inter-heat sources distance and welding speed, on weld geometry were investigated for pulsed Nd:YAG laser/GTAW hybrid welding of 304 stainless steel. Heat transfer efficiency of pulsed Nd:YAG laser/GTAW hybrid welding process was quantitativly analyzed based on rosenthal equation. Furthermore, melting efficiency was determined from the measured welding seams cross section area.

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Residual Stress and Bead Profile Analysis of Pulsed Nd:YAG Laser Lap Welding

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.284-287.915 ◽

2013 ◽

Vol 284-287 ◽

pp. 915-918

Author(s):

Tsung Pin Hung ◽

Chao Ming Hsu ◽

Ah Der Lin ◽

Jao Hwa Kuang

Keyword(s):

Heat Transfer ◽

Residual Stress ◽

Nd:Yag Laser ◽

Pulsed Laser ◽

Welding Process ◽

Surface Flux ◽

Pulsed Nd:Yag Laser ◽

Finite Element Software ◽

Laser Lap Welding ◽

Lap Welding

The weld bead temperature distribution and shape during pulsed Nd:YAG laser lap welding are studied. A volumetric heat source model is derived to include the surface flux and the keyhole heat transfer effects in the pulsed laser lap welding process. The proposed pulsed laser heat transfer mode is employed in a simulation with the commercial finite element software Marc. The numerically computed results of the weld pool dimensions are compared with the experimental results. The comparison shows a good agreement between the simulated and measurement results, indicating that the proposed model is feasible. The results reveal that the pulse duration and spot pitch have considerable influence on the temperature field distribution and the residual stress distribution.

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