scholarly journals Investigation of Laser-material Interaction in Case of Aluminium Brazing Process

2018 ◽  
Author(s):  
Tamás Markovits ◽  
András Jászberényi
Keyword(s):  
Co2 Laser ◽  
Laser Heating ◽  
Laser Energy ◽  
Research Work ◽  
Base Material ◽  
Laser Source ◽  
Laser Material ◽  
Heating Source ◽  
Laser Absorption ◽  
Material Interaction

This research work is connected to the applicability of laser source in case of brazing of aluminium materials. Based on our earlier research results it become clear that the brazing flux material is able to improve the laser absorption in case CO2 laser source. A new brazing flux material (Fontargen F 400 MD EVO2) and the CO2 laser interactions were investigated to determine the applicability of laser as a heating source. The application of laser strongly depend on the value of absorption of laser energy into the aluminium base material. From our new result it can be seen that the applied flux can improve the laser absorption, thus the laser heating, but the implementation of brazing process with this flux material brings further challenges.

Characteristics of Nanopatterns and the Associated Thermal Mechanisms During Near Field Laser-Material Interaction of Nanosecond Laser on Different Targets

2009 ◽  
Author(s):  
Vijay M. Sundaram ◽  
Sy-Bor Wen
Keyword(s):  
Near Field ◽  
Target Material ◽  
Optical Microscope ◽  
Laser Source ◽  
Nanosecond Laser ◽  
Metallic Surfaces ◽  
Experimental Conditions ◽  
Laser Material ◽  
Material Conditions ◽  
Material Interaction

Nano-patterns are generated on semiconducting and metallic surfaces through coupling an apertured near field scanning optical microscope (NSOM) with a pulsed laser source in this study. To understand the dominant mechanisms for the generation of the nano-patterns, a series of experimental measurement of the size and shape of nano-patterns generated on targets under different experimental conditions with different targets is conducted. The characteristic dimensions of nano-patterns show dependence on optical properties of the target material. The qualitative trend of the variation of nano-patterns as a function of laser and material conditions indicates that the dominant mechanisms for the generation of nano-patterns through a combination of nanosecond laser and an apertured NSOM under different conditions studied is near field laser-material interaction.

Pulsed-CO2 laser-material interaction: thermomechanical effects

1993 ◽  
Author(s):  
Christophe Prat ◽  
Michel L. Autric ◽  
Georges Inglesakis
Keyword(s):  
Co2 Laser ◽  
Laser Material ◽  
Pulsed Co2 Laser ◽  
Material Interaction ◽  
Thermomechanical Effects

Pulsed CO2 laser-material interaction: mechanical coupling and reflected and scattered radiation

1991 ◽  
Author(s):  
Prat Christophe ◽  
Michel L. Autric ◽  
Georges Inglesakis ◽  
Dominique Astic
Keyword(s):  
Co2 Laser ◽  
Scattered Radiation ◽  
Laser Material ◽  
Mechanical Coupling ◽  
Pulsed Co2 Laser ◽  
Material Interaction

Modeling of Laser Coagulation of Tissue With MRI Temperature Monitoring

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Xin Chen ◽  
Gerald M. Saidel
Keyword(s):  
Temperature Distribution ◽  
Magnetic Resonance ◽  
Laser Heating ◽  
Laser Energy ◽  
Magnetic Resonance Images ◽  
Laser Source ◽  
Laser Coagulation ◽  
Thermal Coagulation ◽  
Minimal Invasiveness ◽  
Coagulation Process

Light energy from a laser source that is delivered into body tissue via a fiber-optic probe with minimal invasiveness has been used to ablate solid tumors. This thermal coagulation process can be guided and monitored accurately by continuous magnetic resonance imaging (MRI) since the laser energy delivery system does not interfere with MRI. This report deals with mathematical modeling and analysis of laser coagulation of tissue. This model is intended for “real-time” analysis of magnetic resonance images obtained during the coagulation process to guide clinical treatment. A mathematical model is developed to simulate the thermal response of tissue to a laser light heating source. For fast simulation, an approximate solution of the thermal model is used to predict the dynamics of temperature distribution and tissue damage induced by a laser energy line source. The validity of these simulations is tested by comparison with MRI-based temperature data acquired from in vivo experiments in rabbits. The model-simulated temperature distribution and predicted lesion dynamics correspond closely with MRI-based data. These results demonstrate the potential for using this combination of fast modeling and MRI technologies during laser heating of tissue for online prediction of tumor lesion size during laser heating.

Selective Laser Sintering of Resin-Coated Sands—Part I: The Laser-Material Interaction

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Fabrizio Quadrini ◽  
Loredana Santo
Keyword(s):  
Focal Spot ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Laser Source ◽  
Layer By Layer ◽  
Sintering Process ◽  
New Approach ◽  
Laser Material ◽  
Definition Of ◽  
Material Interaction

Selective laser sintering of precoated sands is a process utilized to produce molds and cores for rapid casting by adding sand layer by layer and heating it using a laser beam. During the process, the resin flows and binds the grains; subsequently, an oven is used for the postcuring treatment to complete the curing of the resin. The aim of this paper was to study the laser-material interaction using a diode laser to directly obtain the material consolidation. It was the first step in the definition of a new approach for process investigation and innovation. Two main aspects were investigated with the laser source in a standstill position: first, the influence of the laser power, the location of the focal spot, and the exposure time on sand consolidation; second, the shape and dimension of cured samples depending on the process parameters. The experimental data, in terms of weight and size of the hardened sands, were analyzed, and a master curve was found. In Part II of this paper the selective laser sintering process will be implemented to produce shells.

scholarly journals Simulation of the laser-material interaction of ultrashort pulse laser processing of silicon nitride workpieces and the key factors in the ablation process

2021 ◽  
Author(s):  
Babak Soltani ◽  
Faramarz Hojati ◽  
Amir Daneshi ◽  
Bahman Azarhoushang
Keyword(s):  
Mathematical Model ◽  
Laser Ablation ◽  
Pulse Laser ◽  
Ultrashort Pulse ◽  
Laser Processing ◽  
Laser Power ◽  
Removal Rate ◽  
Ultrashort Pulse Laser ◽  
Laser Material ◽  
Material Interaction

AbstractUnderstanding the laser ablation mechanism is highly essential to find the effect of different laser parameters on the quality of the laser ablation. A mathematical model was developed in the current investigation to calculate the material removal rate and ablation depth. Laser cuts were created on the workpiece with different laser scan speeds from 1 to 10 mm s−1 by an ultrashort pulse laser with a wavelength of about 1000 nm. The calculated depths of laser cuts were validated via practical experiments. The variation of the laser power intensity on the workpiece’s surface during laser radiation was also calculated. The mathematical model has determined the laser-material interaction mechanism for different laser intensities. The practical sublimation temperature and ablated material temperature during laser processing are other data that the model calculates. The results show that in laser power intensities (IL) higher than 1.5 × 109 W cm−2, the laser-material interaction is multiphoton ionisation with no effects of thermal reaction, while in lower values of IL, there are effects of thermal damages and HAZ adjacent to the laser cut. The angle of incidence is an essential factor in altering incident IL on the surface of the workpiece during laser processing, which changes with increasing depth of the laser cut.

Cu-Direct Laser Drilling of Blind Via-Hole in Multi-Layer PWBs: Influence of Surface Treatment on Drilled Hole Quality

2009 ◽  
Author(s):  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Keiji Ogawa ◽  
Tsukasa Ayuzawa
Keyword(s):  
Surface Treatment ◽  
Co2 Laser ◽  
Copper Foil ◽  
Laser Energy ◽  
Copper Surface ◽  
Laser Drilling ◽  
Hole Quality ◽  
Direct Laser ◽  
Overhang Length ◽  
Direct Drilling

This report describes the quality assessment of Blind Via Holes (BVHs) of Printed Wiring Boards (PWBs) drilled by a CO2 laser using Cu-direct drilling. In the Cu-direct drilling method, the copper foil and the build-up layer are melted at the same time, and the surface is treated to increase the laser energy absorbed by the copper foil since an untreated copper surface reflects most of the 10.6-μm-wavelength CO2 laser beam. However, there are few reports dealing with Cu-direct laser drilling of PWBs. In addition, when copper and resin with different processing thresholds are drilled at the same time, occurrences of a defect called overhang have been observed. So, in this report, first we propose a new method using thermography to measure the absorptance of a PWB surface for a CO2 laser. Moreover, we investigate how surface treatment of the outer copper foil influences the quality of a laser-drilled hole. Then, we observe the circumference of a point irradiated with the CO2 laser and explain how melting processes are different from surface treatment. Finally, based on the research we establish a method in order to cut down the overhang length as a parameter of drilled-hole quality. We also show that a high absorptance improves BVH quality.

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