Effects of superposition of 532 nm and 1064 nm wavelengths in copper micro-welding by pulsed Nd:YAG laser

Maina, Martin Ruthandi; Okamoto, Yasuhiro; Hamada, Kazuki; Okada, Akira; Nakashiba, Shin Ichi; Nishi, Norio

doi:10.1016/j.jmatprotec.2021.117388

Cited by 29 publications

(4 citation statements)

References 26 publications

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“…The choice of wavelengths also relevant to Nd:YAG laser functioning, which frequently emits invisible light in at longer wavelength and serves in laser-based devices. 70 The electro-optical effect (Pockel's effect) is an essential nonlinear effect used in many applications. As shown in Table 4 , for all four clusters, the values of β (− ω ; ω ,0) and β (−2 ω , ω , ω ) at ω = 0.0240 are higher than the corresponding values at ω = 0.0856.…”

Section: Resultsmentioning

confidence: 99%

Superalkali nature of the Si₉M₅ (M = Li, Na, and K) Zintl clusters: a theoretical study on electronic structure and dynamic nonlinear optical properties

Ahsin,

Qamar,

Muthu

et al. 2024

RSC Adv.

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Section: Resultsmentioning

confidence: 99%

Superalkali nature of the Si₉M₅ (M = Li, Na, and K) Zintl clusters: a theoretical study on electronic structure and dynamic nonlinear optical properties

Ahsin,

Qamar,

Muthu

et al. 2024

RSC Adv.

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“…To investigate the frequency-dependent NLO responses of the current complexes, we chose 532 and 1064 nm as transparent regions since the complexes display significant absorbance in between 700 nm and 1016 nm. The choice of wavelength (1064 nm) is also relevant to Nd:YAG laser functioning, which frequently emits invisible light in 1064 nm and serves in laser-based devices [ 72 ]. The electro-optic effect is the modification of a medium’s refractive index produced by an electric field.…”

Section: Resultsmentioning

confidence: 99%

Theoretically designed M@diaza[2.2.2]cryptand complexes: the role of non-covalent interactions in promoting NLO properties of organic electrides

Ahsin,

Qamar,

et al. 2024

Science and Technology of Advanced Materials

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Organic excess electron compounds with significant nonlinear optical (NLO) properties are widely employed in optoelectronic applications. Herein, single-alkali metals with diaza[2.2.2] cryptand (M@crypt,M=Li, Na, and K) are investigated for optoelectronic and NLO properties by using the density functional theory. Thermodynamic and kinetic stabilities of present complexes are computed through interaction energy (E int ) and ab-initio molecular dynamic (AIMD) simulations. M@crypt complexes carry excess electrons and mimic molecular electrides. Quantum theory of atoms in molecules (QTAIM) analysis and reduced density gradient (RDG) spectra demonstrate the roles of the weak van der Waals (vdW) interactions between metal and complexant. The remarkable hyperpolarizability (β o ) value up to 1.41 × 10 6 au may be credited to the presence of loosely bound excess electrons. The hyper Rayleigh scattering hyperpolarizability (β HRS ) is recorded up to 1.31 × 10 6 au for the K@crypt. Furthermore, frequency-dependent first-order and second-order hyperpolarizability is more prominent at the applied frequency of ω = 0.042823 au. The electron localizing function (ELF) and localized orbital locator (LOL) analysis further disclose the nature of interaction between alkali metal and complexant. The TD-DFT method is adopted to get excited state parameters and absorbance properties. An electron density difference map (EDDM) is exploited to evaluate the orbital contributions in excited states. Hence, the studied electride may become a promising candidate for NLO materials. We anticipate that the present work will provide insight into further development of molecular electride for optoelectronic applications.

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“…However, the process and the deposition track should not be negatively influenced by this. Laser welding with irradiation in the visible field, including mixing with conventional NIR lasers, is mainly used for welding high reflective materials as for example copper [38][39][40][41][42]. Furthermore, systems with two separate spots for lapped joints are also used [43,44].…”

Section: Optical Emission Spectroscopy (Oes) In Laser Welding Processesmentioning

confidence: 99%

Laser Cladding With Combined NIR and Blue Diode Laser Including In-Line Atomic Emission Spectroscopy

Schmidt

Kohler²,

Gerhard

et al. 2023

Lasers Manuf. Mater. Process.

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For Directed Energy Deposition processes (DED) lasers in the near infrared (NIR) as well as in the infrared (IR) range are predominantly used. Recent developments have also made high-power lasers in the visible spectrum available. As the DED process is used for cladding of surfaces, repairing and additive manufacturing of components, process monitoring and control methods are necessary to ensure a consistent manufacturing quality. Optical emission spectroscopy (OES) of the process radiation can provide information on process conditions and the deposition layer during DED processes. However, DED processes are in the heat conduction regime and superimposed broad spectral emissions dominate the wavelength specific signals. The object of this work is to compare the process behavior using a NIR and blue diode laser separately as well as in combination. The influence of the laser wavelength on the cladding result as well as on the emitted process radiation is to be determined. Therefore, single tracks of Co-based powder (MetcoClad21) were clad on an S235 base material by using each laser source separately as well as in combination. Both laser beams were combined within a single hybrid optic. While the scan speed and powder feed rate remained constant, the laser power was varied. Single spectra have been recorded from the process using a spectrometer. Single spectra are sorted and element lines were identified. Only non-ionised elements could be detected, with chromium appearing frequently. It was shown that comparable results in terms of cladding quality can be produced independently from the laser wavelength. In fact, less laser power (app. 30% less, 1 kW at 980 nm (NIR) compared to 0.7 kW at 450 nm (blue)) was needed aiming for comparable results in geometrical factors (as dilution, height, depth, width) and homogeneity (chemical composition distribution) by using blue laser irradiation. Furthermore, more spectrometric signals (approx. 2–28 times more) were detected compared to experiments using only NIR irradiation with the same laser power. This effect is particularly high at low laser powers and decreases with increasing power. Hence, it is possible to enable in-line process analysis by adding blue laser irradiation to the mix of the beam.

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Effects of superposition of 532 nm and 1064 nm wavelengths in copper micro-welding by pulsed Nd:YAG laser

Cited by 29 publications

References 26 publications

Superalkali nature of the Si₉M₅ (M = Li, Na, and K) Zintl clusters: a theoretical study on electronic structure and dynamic nonlinear optical properties

Superalkali nature of the Si₉M₅ (M = Li, Na, and K) Zintl clusters: a theoretical study on electronic structure and dynamic nonlinear optical properties

Theoretically designed M@diaza[2.2.2]cryptand complexes: the role of non-covalent interactions in promoting NLO properties of organic electrides

Laser Cladding With Combined NIR and Blue Diode Laser Including In-Line Atomic Emission Spectroscopy

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Effects of superposition of 532 nm and 1064 nm wavelengths in copper micro-welding by pulsed Nd:YAG laser

Cited by 29 publications

References 26 publications

Superalkali nature of the Si9M5 (M = Li, Na, and K) Zintl clusters: a theoretical study on electronic structure and dynamic nonlinear optical properties

Superalkali nature of the Si9M5 (M = Li, Na, and K) Zintl clusters: a theoretical study on electronic structure and dynamic nonlinear optical properties

Theoretically designed M@diaza[2.2.2]cryptand complexes: the role of non-covalent interactions in promoting NLO properties of organic electrides

Laser Cladding With Combined NIR and Blue Diode Laser Including In-Line Atomic Emission Spectroscopy

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Product

Resources

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Superalkali nature of the Si₉M₅ (M = Li, Na, and K) Zintl clusters: a theoretical study on electronic structure and dynamic nonlinear optical properties

Superalkali nature of the Si₉M₅ (M = Li, Na, and K) Zintl clusters: a theoretical study on electronic structure and dynamic nonlinear optical properties