Relationship between weld quality and optical emissions in underwater Nd: YAG laser welding

Zhang, Xudong; Chen, Wuzhu; Ashida, Eiji; Matsuda, Fukuhisa

doi:10.1016/s0143-8166(03)00031-9

Cited by 49 publications

(25 citation statements)

References 6 publications

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“…A system was also developed to perform real-time evaluations of the weld quality with the use of fuzzy pattern recognition with the measured signals. The UV and IR signals received from photodiodes were also used for weld quality assessment in [58,59]. The novelty in [58] is the implementation of such a sensing technology and quality inspection in underwater laser welding.…”

Section: Optical Signal Techniquesmentioning

confidence: 99%

“…The UV and IR signals received from photodiodes were also used for weld quality assessment in [58,59]. The novelty in [58] is the implementation of such a sensing technology and quality inspection in underwater laser welding. The authors claimed that the shielding condition of the local dry cavity was a significant factor for adequate penetration.…”

Section: Optical Signal Techniquesmentioning

confidence: 99%

See 1 more Smart Citation

Quality assessment in laser welding: a critical review

Stavridis

Papacharalampopoulos

Stavropoulos

2017

Int J Adv Manuf Technol

172

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Quality assessment methods and techniques for laser welding have been developed both in-and post-process. This paper summarizes and presents relevant studies being classified according to the technology implemented (vision, camera, acoustic emissions, ultrasonic testing (UT), eddy current technique (ECT)) for the quality inspection. Furthermore, the current review aims to map the existing modeling approaches used to correlating measured weld characteristics and defects with the process parameters. Research gaps and implications of the quality assessment in laser welding are also described, and a future outlook of the research in the particular field is provided.

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Section: Optical Signal Techniquesmentioning

confidence: 99%

Section: Optical Signal Techniquesmentioning

confidence: 99%

Quality assessment in laser welding: a critical review

Stavridis

Papacharalampopoulos

Stavropoulos

2017

Int J Adv Manuf Technol

172

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show abstract

“…Similar experiments were implemented in , Park 2002) to develop a relationship between the plasma and spatter and bead shape according to the welding variables, based on a multiple regression analysis and neural network to estimate the penetration depth and width of the weld bead. In (Sforza 2002, Zhang 2004, IR and UV signals were captured and analyzed to detect the IR and UV waveband of the optical emissions induced in the underwater laser welding and searched for a relationship between the optical signals and the weld quality with various shielding conditions.…”

Section: Optical Signal Sensing Systemmentioning

confidence: 99%

Laser Welding: Techniques of Real Time Sensing and Control Development

Na¹,

Stone²

2010

Laser Welding

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“…The amplitude of dispersion can be correlated both to the reflectance of the laser impact area and thickness of gold deposed on the Kovar mainly composing subassembly 1. The absorbance of laser energy is related to the thickness of the gold, water concentration, and roughness of the material surface [18]- [20]. The thin film of gold allows the adsorption of infrared the 1-m wavelength laser Nd:YAG beam.…”

Section: Optical Misalignment Distribution Using Process Dispersionmentioning

confidence: 99%

Simulations of Thermomechanical Stresses and Optical Misalignment in 1550-nm Transmitter Optoelectronic Modules Using FEM and Process Dispersions

Deshayes

Béchou

Verdier

et al. 2008

IEEE Trans. Comp. Packag. Technol.

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Expertise of packaging for optoelectronic components requires the solution of optical, mechanical, and electrical problems in the same way. The purpose of this paper is to present three-dimensional simulations using finite-element method (FEM) of thermomechanical stresses and strains in 1550-nm laser modules induced by Nd:YAG crystal laser welds and thermal cycles on main subassembly laser submount. Nonlinear FEM computations, taking into account of experimental ( ) measured curves, show that thew laser welding process can induce high level of strains in columns of the laser platform, bearing the laser diode, responsible of an optical axis shift and a gradual drop of the optical power in relation with relaxation of accumulated stresses in the subassembly (W. M. Sherry et al., "High performance optoelectronic packaging for 2.5 and 10 Gb/s laser modules," in Proc. Electron. Compon. Technol. Conf., 1996, pp. 620-627). Typical stresses are close to 160 MPa with drift about 5 MPa with the dispersion of energy level of the laser Nd: YAG beam. The introduction of both material and process dispersion in order to evaluate their impact on product lifetime distribution has been taking into account. In the case of thermal cycles, stresses can occur on elements sensitive to coefficient of thermal expansion mismatches such as solder joints between the laser platform and thermoelectric cooler and as fiber glued into the pigtail leading to crack propagation with sudden drop of optical power. A previous paper demonstrated that laser submount is the most sensitive part of optical system (Deshayes, et al., "Three-dimensional FEM simulations of thermal mechanical stresses in 1.55 m laser modules," Microelectron. Rel., vol. 43, no. 7, pp. 1125-1136, Jul. 2003). Experimental analyses were also conducted to correlate simulation results and monitor the output optical power of laser modules after 500 thermal cycles ( 40 C + 85 C VRT). Index Terms-Distributed feedback (DFB), finite-element model (FEM), laser YAG, neodymium-doped yttrium aluminium garnet (NdYAG), optical module, reliability, welding.

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Relationship between weld quality and optical emissions in underwater Nd: YAG laser welding

Cited by 49 publications

References 6 publications

Quality assessment in laser welding: a critical review

Quality assessment in laser welding: a critical review

Laser Welding: Techniques of Real Time Sensing and Control Development

Simulations of Thermomechanical Stresses and Optical Misalignment in 1550-nm Transmitter Optoelectronic Modules Using FEM and Process Dispersions

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