scholarly journals Simulation of laser drilling of Inconel X-750 and Ti-5Al-2.5Sn sheets using COMSOL

2021 ◽  
Vol 61 (4) ◽  
pp. 526-536
Author(s):  
Muammel M. Hanon ◽  
Ziad A. Taha ◽  
László Zsidai
Keyword(s):  
Cross Section ◽  
Peak Power ◽  
Laser Pulses ◽  
Laser Drilling ◽  
Comsol Multiphysics ◽  
Optimum Conditions ◽  
Hole Quality ◽  
Optimum Parameters ◽  
Entire Thickness ◽  
Entire Depth

The ability of COMSOL Multiphysics 5.2 software to carry out the simulation of laser drilling processes in Inconel X-750 and Ti-5Al-2.5Sn sheets was investigated in this study. A JK 701 pulsed Nd:YAG laser was used for drilling through the entire depth of Inconel X-750 and Ti-5Al-2.5Sn plates of 2 mm and 3 mm thicknesses using laser pulses of a millisecond in time. The laser parameters are varied in different combinations for well-controlled drilling through the entire thickness of the plates. Effects of laser peak power and pulse duration have been determined via the studying of the temperature distribution on the cross-section of the images taken in the simulation tests. Characterizing the optimum conditions obtained from the combination of parameters that improve hole quality is an essential aim in this paper. This work's outcomes might be helpful for researchers in terms of the optimum parameters proposed when studying the laser drilling of the mentioned alloys experimentally.

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.

The diffraction-ray model of single filamentation of femtosecond laser pulses for estimating characteristics of the multiple filamentation domain in air

2021 ◽  
Vol 64 (1) ◽  
pp. 154-164
Author(s):  
A.A. Zemlyanov ◽  
◽  
Y.E. Geints ◽  
O.V. Minina ◽  
◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Beam ◽  
Peak Power ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Small Scale ◽  
Beam Forming ◽  
Physical Processes ◽  
Multiple Filamentation ◽  
Number Increase

The characteristics of the domain of multiple filamentation of femtosecond laser pulses in air were estimated based on the single filamentation model. As the single filamentation model, the diffraction-ray model is considered. It is based on the representation of a laser beam as a set of diffraction-ray tubes nested in each other that do not intersect in space and do not exchange energy with each other. In this situation changes in tubes shape and cross section during propagation demonstrate the effect of physical processes that occur with radiation in the medium. It is shown that the use of this model for interpreting experimental results and predicting effects is effective. In particular, it was demonstrated that the radius of small-scale intensity inhomogeneities in the profile of a centimeter laser beam, forming the domain of multiple filamentation of subterawatt femtosecond laser pulses, is several millimeters. The power in these inhomogeneities varies from several units to several tens of gigawatts. Telescoping the initial laser beam, leading to an increase in its radius, also expands the sizes of the initial small-scale intensity inhomogeneities and reduces the power contained in them. As a result of this, the coordinate of the filamentation beginning shifts along the path from the source of laser pulses. As the peak power in the beam increases, the length of the filaments and their number increase.

Bundled hollow optical fibers for transmission of high-peak-power Q-switched Nd:YAG laser pulses

2006 ◽  
Vol 45 (27) ◽  
pp. 7174 ◽  
Author(s):  
Ozgur Yilmaz ◽  
Mitsunobu Miyagi ◽  
Yuji Matsuura
Keyword(s):  
Optical Fibers ◽  
Nd:Yag Laser ◽  
Peak Power ◽  
Laser Pulses ◽  
High Peak ◽  
High Peak Power

Parametric Analysis of Laser Beam Percussion Drilling for Thin Titanium Alloy Sheet Using Yb: Yag Fiber Laser

2021 ◽  
pp. 1-24
Author(s):  
Mohit Singh ◽  
Sanjay Mishra ◽  
Vinod Yadava ◽  
J. Ramkumar
Keyword(s):  
Laser Beam ◽  
Fiber Laser ◽  
Pulse Width ◽  
Peak Power ◽  
Laser Pulses ◽  
Pulse Frequency ◽  
Alloy Sheet ◽  
Power Pulse ◽  
The Individual ◽  
Percussion Drilling

Laser beam percussion drilling (LBPD) can create high density holes in aerospace materials with the repeated application of laser pulses at a single spot. In this study, one-parameter-at-a-time approach has been used to investigate the individual effect of peak power, pulse width and pulse frequency on geometrical accuracy and metallurgical distortion during LBPD of 0.85[Formula: see text]mm thick Ti–6Al–4V sheet using 200[Formula: see text]W Yb:YAG fiber laser. It has been found that the output parameters behave differently at the higher and lower values of a particular input process. The increase of pulse width from 1 to 1.50[Formula: see text]ms increases hole taper by 20% whereas the same corresponding change from 1.50 to 2.00[Formula: see text]ms reduces the taper by 20%. The increase of pulse frequency from 10 to 50[Formula: see text]Hz reduces hole circularity by 40% but the same proportionate change from 50 to 90[Formula: see text]Hz reduces circularity by 79%. Increase of peak power from 1.70 to 2.0[Formula: see text]kW increases hole taper by 8% but the corresponding increase from 2 to 2.30[Formula: see text]kW is 143%.

scholarly journals Steady state analysis of regular hollow pyramidal radiating fin with triangular cross-section

2015 ◽  
Vol 19 (1) ◽  
pp. 59-68
Author(s):  
Vijaikrishnan Venkataramanan ◽  
Ramakrishnan Madhavaneswaran ◽  
Siva Shanmugam
Keyword(s):  
Heat Transfer ◽  
Heat Loss ◽  
Cross Section ◽  
Working Conditions ◽  
Unit Mass ◽  
Design Parameters ◽  
Steady State Analysis ◽  
Fin Efficiency ◽  
Triangular Cross Section ◽  
Optimum Parameters

A new configuration for space radiator is proposed introducing a fin of regular hollow pyramidal shape with triangular cross section, giving a higher improvement in heat loss per unit mass than that of other corresponding configurations previously proposed under same working conditions. The significance of the present configuration and its advantage over other regular hollow configurations are discussed and effect of various design parameters on heat transfer is analyzed in presence of radiation interaction with an isothermal base attached to it. Optimum parameters are identified for which improvement in heat loss per unit mass is the maximum. It is found that the fin efficiency decreases with increase in the emissivity & height of the fin and increases with increase in thickness & top radius of the fin. Correlations are presented for optimum design parameters, optimum improvement in heat loss per unit mass and fin efficiency.

Structural and Morphological of Pulsed Laser Deposited Magnesium Phthalocyanine (MgPc) Thin Film

2020 ◽  
Vol 29 ◽  
pp. 15-21
Author(s):  
Noor M. Ibrahim ◽  
Eman K. Hassan
Keyword(s):  
Thin Film ◽  
Surface Morphology ◽  
Structural Characteristics ◽  
Pulsed Laser ◽  
Laser Pulses ◽  
X Ray Diffraction ◽  
Characteristic Peak ◽  
Monoclinic Form ◽  
Optimum Parameters ◽  
Diffraction Peaks

Magnesium Phthalocyanine (MgPc) was deposited on a glass substrate by pulsed laser deposition (PLD) using Q-Switching Nd: YAG laser with wavelength 1064(nm), (6Hz) Repetition rate, in addition to different laser energies (200,300,400 and 500 mJ) at room temperature under vacuum condition with (10-3torr). All films were annealed at (298K) for 1hour to attain crystallinity. X-ray diffraction of MgPc powder indicated the fact that MgPc crystallizes in polycrystalline with a monoclinic structure While comparing the MgPc of films, it’s found the intensity of characteristic peak is high as the number and energy of laser pulses increase and the crystallize is monoclinic form is observed in β-form. Miller indices, hkl, values for every one of the diffraction peaks in the spectrum of the XRD have been computed. The characteristic peak of Phthalocyanine (MgPc) is found at 2θ value 6.9137o with the hkl value of {100} for both MgPc powder and deposited thin film. The surface morphology of the films showed more uniform sized grains. EDX and FESEM analysis has shown that there has been an enhancement in the crystallinity and surface morphology as a result of the increase of laser energies and for finding the optimum parameters for which film provides more efficient structural characteristics.

scholarly journals Experimental Investigation of Productivity, Specific Energy Consumption, and Hole Quality in Single-Pulse, Percussion, and Trepanning Drilling of IN 718 Superalloy

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4610 ◽  
Author(s):  
Shoaib Sarfraz ◽  
Essam Shehab ◽  
Konstantinos Salonitis ◽  
Wojciech Suder
Keyword(s):  
Experimental Investigation ◽  
Energy Consumption ◽  
Specific Energy ◽  
Material Removal ◽  
Specific Energy Consumption ◽  
Single Pulse ◽  
Laser Drilling ◽  
Fibre Laser ◽  
Hole Quality ◽  
Multi Objective

Laser drilling is a high-speed process that is used to produce high aspect ratio holes of various sizes for critical applications, such as cooling holes in aero-engine and gas turbine components. Hole quality is always a major concern during the laser drilling process. Apart from hole quality, cost and productivity are also the key considerations for high-value manufacturing industries. Taking into account the significance of improving material removal quantity, energy efficiency, and product quality, this study is performed in the form of an experimental investigation and multi-objective optimisation for three different laser drilling processes (single-pulse, percussion, and trepanning). A Quasi-CW fibre laser was used to produce holes in a 1 mm thick IN 718 superalloy. The impacts of significant process parameters on the material removal rate (MRR), specific energy consumption (SEC), and hole taper have been discussed based on the results collected through an experimental matrix that was designed using the Taguchi method. The novelty of this work focuses on evaluating and comparing the performance of laser drilling methods in relation to MRR, SEC, and hole quality altogether. Comparative analysis revealed single-pulse drilling as the best option for MRR and SEC as the MRR value reduces with percussion and trepanning by 99.70% and 99.87% respectively; similarly, percussion resulted in 14.20% higher SEC value while trepanning yielded a six-folds increase in SEC as compared to single-pulse drilling. Trepanning, on the other hand, outperformed the rest of the drilling processes with 71.96% better hole quality. Moreover, optimum values of parameters simultaneously minimising SEC and hole taper and maximising MRR are determined using multi-objective optimisation.

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