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Impact of laser beam oscillation strategies on surface treatment of microalloyed steel J. Laser Appl. (IF 1.41) Pub Date : 2020-09-22 Handika Sandra Dewi; Joerg Volpp
The depth homogeneity of laser-treated zones is one possible factor to define the quality and efficacy of altered mechanical properties in materials. For instance, half-rounded cross-sectional shapes of laser hardened zones using Gaussian beams provide dissimilar hardened depth in the edges and center of the treated area. This means that the in-depth distribution of compressive residual stress varies
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Influence of hatch spacing and laser spot overlapping on heat transfer during laser powder bed fusion of aluminum alloy J. Laser Appl. (IF 1.41) Pub Date : 2020-09-22 Ghulam Rasul Nazami; Seshadev Sahoo
Direct metal laser sintering is a kind of laser powder bed fusion process that emerged as an advanced manufacturing process in the recent era of industry 4.0. This is a rapid manufacturing process where repeated melting and solidification takes place during scanning of the powder bed. The characteristics of the as-built component depend on the melting and solidification behavior which is directly influenced
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Thermophysical modeling of selective laser ablation processing of lithium-ion battery cathodes J. Laser Appl. (IF 1.41) Pub Date : 2020-09-28 Sebastian Enderle; Marius Bolsinger; Simon Ruck; Volker Knoblauch; Harald Riegel
The microstructural optimization of lithium-ion battery (LiB) electrodes has recently gained a lot of interest. Versatile approaches to enhance fast charging abilities of LiB electrodes are the subject of current research. One of these approaches is the laser based photothermic removal of superficial inactive electrode components in order to improve the accessibility of the active material particles
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Laser-processing of grinded and mechanically abraded Nb-surfaces J. Laser Appl. (IF 1.41) Pub Date : 2020-09-30 V. Porshyn; P. Rothweiler; D. Lützenkirchen-Hecht
The effect of pulsed laser polishing on rough niobium surfaces was investigated. We created different well-defined roughness profiles with standard emery papers and subsequently remelted random surface areas with a size of about 2 × 2 mm2 with nanosecond laser pulses (wavelength of 1064 nm, pulse length of 10 ns). Pristine as well as laser-treated surfaces were investigated using optical profilometry
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Computation of effective source size for extended sources J. Laser Appl. (IF 1.41) Pub Date : 2020-10-05 Wesley J. Marshall
A laser hazard evaluation compares the potential laser exposure to the maximum permissible exposure (MPE). Direct intrabeam viewing of a collimated laser beam produces a minimally sized retinal image. Viewing other laser sources often produces a larger retinal image known as an extended source. An optical limiter is designed to protect the eye from direct laser exposure through a combination of absorption
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Factors influencing the tensile strength of carbon fiber reinforced plastic laminates for laser machining method and the underlined mechanisms J. Laser Appl. (IF 1.41) Pub Date : 2020-10-07 Yunxia Ye; Tingting Du; Haonan Li; Xudong Ren; Haijuan Kong; Naifei Ren
This paper presents an investigation into the influence of laser drilling on the tensile strength of carbon fiber reinforced plastic (CFRP) laminates of 1 and 2.5 mm thickness. The CFRP laminates were drilled using the microsecond laser, nanosecond laser, and picosecond laser, and the heat-affected zone (HAZ) was characterized and measured by optical microscopy. Through setting laser parameters, specimens
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Comparative investigation on single laser beam and dual laser beam for lap welding of aluminum alloy J. Laser Appl. (IF 1.41) Pub Date : 2020-10-19 Lin Chen; Gaoyang Mi; Xiong Zhang; Chunming Wang
Aluminum alloy is considered to be one of the ideal materials for light-weighting on aerospace and new energy automotive. Laser welding without a filler wire is an efficient way for weight reduction. The common defects in laser welding of aluminum alloys are porosities and cracks, resulting in poor mechanical performances and short service life of joints. In order to investigate the methods to suppress
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Prediction of surface roughness of laser selective metallization of ceramics by multiple linear regression and artificial neural networks approaches J. Laser Appl. (IF 1.41) Pub Date : 2020-10-26 Li Wang; Lisbeth Silva; Robert Süß-Wolf; Jörg Franke
Laser selective metallization of ceramics (LMC) has been widely applied to prepare high-quality electrical patterns on ceramic circuit carriers. As the dominating factor, surface roughness after laser treatment is controlled mostly by the laser technical parameters, such as laser power, scanning velocity, and laser frequency. Therefore, establishing an accurate relation between the surface roughness
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Temperature behavior of metal surface with moving annular hollow laser heat source J. Laser Appl. (IF 1.41) Pub Date : 2020-10-26 Yuting Xu; Xiaohui Zhang; Junyong Shen; Tuo Shi
The temperature distribution characteristics of a moving annular hollow laser beam irradiated on the substrate are studied in this paper. First, through the linear superposition property of potential function, we derive the analytical solution of temperature distribution and the cooling rate of the moving ideal annular hollow heat source. The entransy dissipation rate per unit volume of the annular
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Wear behavior of laser cladded WC-FeAl coating on 321 stainless steel substrate J. Laser Appl. (IF 1.41) Pub Date : 2020-11-09 Alireza Mostajeran; Reza Shoja-Razavi; Morteza Hadi; Mohammad Erfanmanesh; Hadi Karimi
Commonly, the low wear resistance of stainless steels damages them during usage; in order to enhance wear properties, various types of tungsten-carbide-based coatings, such as WC-Co and WC-Ni, could be applied on the steel surface. To improve the mechanical properties of the coatings, instead of nickel- or cobalt-bearing coatings, WC-FeAl composite coating is used. Following the previous studies on
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Real-time continuous estimation of dross attachment in the laser cutting process based on process emission images J. Laser Appl. (IF 1.41) Pub Date : 2020-11-10 Matteo Pacher; Luca Franceschetti; Silvia C. Strada; Mara Tanelli; Sergio M. Savaresi; Barbara Previtali
Laser cutting of metals has become the reference manufacturing technology in sheet metal working thanks to the flexibility and the increased productivity it offers when compared with other competitive technologies. Considering, in particular, the fusion-cutting mode, i.e., when nitrogen is used as an assisting gas, different aspects contribute to the process quality among which dross attachment plays
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Ultralow duty cycle chopper instigated low power continuous wave laser assisted synthesis of silver nanoparticles: A novel approach J. Laser Appl. (IF 1.41) Pub Date : 2020-11-12 M. S. Swapna; A. S. Ashik; R. A. Krishnanunni; V. P. N. Nampoori; S. Sankararaman
This paper is the first report of advancement in the drastic reduction of the laser power density from 105 to 7.5 W/cm2 for the synthesis of silver nanoparticles (SNPs) using a low power (60 mW) continuous-wave (cw) laser and a specially designed ultralow duty cycle (3%) optical chopper wheel for modulating the laser beam at low frequencies (2 Hz). The target is irradiated by keeping it in a liquid
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Improving fluid retention properties of 316L stainless steel using nanosecond pulsed laser surface texturing J. Laser Appl. (IF 1.41) Pub Date : 2020-11-18 Mahmood Al Bashir; Rajeev Nair; Martina M. Sanchez; Anil Mahapatro
Stainless steel has been used as a successful biomaterial for decades. In this study, a pulsed nanosecond laser was used to create patterned surfaces of stainless steel coupons to study the effect of patterning on fluid retention and biocompatibility studies of laser patterned and control surfaces. An AVIA 355 nanosecond pulsed laser was used with different laser parameters to create unique “peak and
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Practical implementation of laser polishing on additively manufactured metallic components J. Laser Appl. (IF 1.41) Pub Date : 2020-11-19 Mark W. McDonald; Wojciech S. Gora; Stuart G. Stevenson; Nick J. Weston; Duncan P. Hand
Due to the continually increasing popularity of metal powder-based additive manufacturing as a production process in recent years, there has been growing research into improving the surface quality of the parts manufactured in this way. Laser polishing offers great potential as a finishing technique due to its flexibility and suitability for automation. However, the complexity of components that can
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Local laser softening of cold forming steels J. Laser Appl. (IF 1.41) Pub Date : 2020-11-24 S. Vogt; A. Weisheit; J. H. Schleifenbaum
The use of as-rolled cold forming steels opens new potential for lightweight construction in the automotive industry. Cold-rolled grades with a tensile strength up to 1100 MPa are on the market. However, the high strength limits the cold forming performance. A local softening in areas of high degree of deformation can be a solution to this conflict. In this work, basic studies on softening of a sheet
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Laser-induced photocatalytic reduction of CO2into methanol over perovskite LaMnO3 J. Laser Appl. (IF 1.41) Pub Date : 2020-09-18 M. Soleimani Varaki; A. Jafari; M. Ebrahimizadeh Abrishami
Perovskite oxides offer efficient photocatalytic properties for CO2 reduction to methanol. In this study, LaMnO3+δ nanocrystals were fabricated by the solgel combustion method. The structural properties including lattice constants, occupancies, Mn–O lengths, and Mn–O–Mn angle were studied by Rietveld refinement. Jahn–Teller distortion and O-2p and Mn-3d hybridization have been investigated using the
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Detection of heavy metals using laser-induced breakdown spectroscopy technique for both horse hair and goat hair J. Laser Appl. (IF 1.41) Pub Date : 2020-09-15 Elshaimaa M. Emara; Hisham Imam; Haiying Song; Shibing Liu
The main purpose of this paper is to use the laser-induced breakdown spectroscopy (LIBS) technique as a fast, noninvasive, and low cost spectro-biochemical analysis laser spectroscopy technique. This study will indicate the qualified performance of LIBS with the proposed optimum conditions as a promising and easy tool for identification, detection, and characterization of trace elements in different
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Beam engineering strategies for high throughput, precise, micro-cutting by 100 W, femtosecond lasers J. Laser Appl. (IF 1.41) Pub Date : 2020-09-03 Girolamo Mincuzzi; Alice Rebière; Marc Faucon; Aurélien Sikora; Rainer Kling
The recent availability on the market of industrial, reliable, ultrashort pulse lasers (UPLs) delivering hundreds of watts has opened the possibility for this technology to significantly increase the machining throughput and address an ever-larger number of industrial applications. Nevertheless, heat accumulation phenomena are observed as soon as the average power P exceeds tens of watts, compromising
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Parameter optimization of selective laser melting fabricated titanium alloy using skin-core and triple contour scanning strategy J. Laser Appl. (IF 1.41) Pub Date : 2020-09-01 Le Wan; Zhixin Xia; Ying Song; Xiaowei Zhang; Fan Liu; Geyan Fu; Shihong Shi
In this paper, the skin-core combined with the triple contour method is proposed to solve the density and roughness problems of selective laser melting. Based on the skin-core strategy, the surface roughness is optimized by laser parameter adjustment, and the high-quality side-surface formation is achieved by the triple contour method. The results showed that the relative density increases first and
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Investigating build geometry characteristics during laser directed energy deposition based additive manufacturing J. Laser Appl. (IF 1.41) Pub Date : 2020-09-01 A. C. Paul; A. N. Jinoop; C. P. Paul; P. Deogiri; K. S. Bindra
Laser directed energy deposition (LDED) is one of the metal additive manufacturing processes for fabricating complex shaped metallic components directly from a digital model using high power lasers and metallic powder. To fabricate components with minimum inaccuracies in build geometry and maximum build economy, optimization of process parameters is significant. In the present work, an experimental
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Laser surface texturing using a single diffractive optical element as an alternative for direct laser interference patterning J. Laser Appl. (IF 1.41) Pub Date : 2020-06-23 Alexander Brodsky; Natan Kaplan
In this work, we introduce a simple and universal optical setup design for laser surface texturing (LST) that provides functionality superior than direct laser interference patterning (DLIP). The method requires only a single periodic diffractive optical element and a focusing lens while enabling unlimited freedom for spatial shaping and amplitude variations. The concept is based on the special behavior
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Potential and challenges of additive manufacturing for topology optimized spacecraft structures J. Laser Appl. (IF 1.41) Pub Date : 2020-06-25 Robin Willner; Stefan Lender; Andreas Ihl; Christoph Wilsnack; Samira Gruber; Ana Brandão; Laurent Pambaguian; Mirko Riede; Elena López; Frank Brueckner; Christoph Leyens
This study focused on the potential of topology optimization (TO) for metallic tertiary structures of spacecrafts produced by the additive manufacturing (AM) technique laser powder bed fusion. First, a screening of existing conventionally manufactured products was carried out to evaluate the benefits of a redesign concerning product performance and the associated economic impact. As a result of the
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Laser marking and coloration of Ti-6Al-4V with ultrashort pulses J. Laser Appl. (IF 1.41) Pub Date : 2020-06-26 Norbert Ackerl; Pascal Gugger; Konrad Wegener
A routine for color marking using oxide layers and laser-induced periodic surface structures is presented. Titanium and alloys thereof are marked with pixelated graphics at a high resolution with tempering colors. A computational approach for the laser path calculation enables a fast-forward marking of complex designs. The color map attained from a laser parameter studies enables vivid coloration.
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Investigation on the formation of grain boundary serrations in additively manufactured superalloy Haynes 230 J. Laser Appl. (IF 1.41) Pub Date : 2020-06-29 M. Haack; M. Kuczyk; A. Seidel; E. López; F. Brückner; C. Leyens
Solid-solution and carbide-strengthened superalloys such as Haynes 230 are the materials of choice for the hot-section components of gas turbines, e.g., combustion cans and transition ducts. Under severe thermal conditions, to which those parts are exposed, creep strength is a crucial property of the related materials during their lifetime. Recently, the introduction of serrated grain boundaries in
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Geometry and absorptance of the cutting fronts during laser beam cutting J. Laser Appl. (IF 1.41) Pub Date : 2020-06-29 Jannik Lind; Florian Fetzer; David Blazquez-Sanchez; Jens Weidensdörfer; Rudolf Weber; Thomas Graf
The geometry of the cutting front and the cutting kerf was measured with an online high-speed x-ray diagnostic system. X-ray videos from fusion cutting of 10 mm thick stainless steel samples were recorded with a frame rate of 1000 Hz. A three-dimensional reconstruction of the time-averaged geometry of the cutting front and cutting kerf out of these images made it possible to apply ray-tracing for calculating
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Comparison of dimensional accuracy and tolerances of powder bed based and nozzle based additive manufacturing processes J. Laser Appl. (IF 1.41) Pub Date : 2020-06-30 Samira Gruber; Christian Grunert; Mirko Riede; Elena López; Axel Marquardt; Frank Brueckner; Christoph Leyens
Additive manufacturing processes have the potential to produce near-net shaped complex final parts in various industries such as aerospace, medicine, or automotive. Powder bed based and nozzle based processes like laser metal deposition (LMD), laser powder bed fusion (LPBF), and electron beam melting (EBM) are commercially available, but selecting the most suitable process for a specific application
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Influence of laser wavelength on the modification of friction between 100Cr6 steel and polytetrafluoroethylene by femtosecond laser-induced periodic surface structures J. Laser Appl. (IF 1.41) Pub Date : 2020-07-02 Stefan Rung; Kevin Bokan; Simon Schwarz; Cemal Esen; Ralf Hellmann
The authors report on surface modification by laser-induced periodic surface structures of different periodicities and modulation depths to modify dry and lubricated tribological properties. Using 220 fs laser pulses in the infrared ( λ 1 = 1030 nm), visible ( λ 2 = 515 nm), and ultraviolet ( λ 3 = 343 nm) spectral regions, the authors periodically structure two-dimensional areas with periodicities
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Physical and mechanical characterization of dissimilar laser welded joints of AISI 316/Cu/SMA using fiber laser technology J. Laser Appl. (IF 1.41) Pub Date : 2020-07-08 Suman Chatterjee; Siba Sankar Mahapatra; Kanwer Singh Arora; Ajit Behera
The present study explores an experimental investigation of dissimilar welding of austenitic stainless steel (AISI 316) with nitinol (NiTi) plates by inserting copper (Cu) as an interlayer using a fiber laser system. The presence of copper influences controlling the formation of brittle intermetallic compounds forming compounds of copper with iron, titanium, and nickel. The weldments are examined to
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Modification of TA15 alloy surface by high-pulse-frequency laser cleaning J. Laser Appl. (IF 1.41) Pub Date : 2020-07-21 Bowen Liu; Gaoyang Mi; Chunming Wang
The original morphology of the oxide layer and the surface of the titanium alloy has a significant impact on manufacturing and processing. The laser cleaning pulse frequency amplitude affects the single pulse energy. It will affect the original morphology of the surface and the compositional changes of the laser-generated oxide layer. This work aims to study the effect of pulse frequency on the surface
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Onlinein situdetection and rapid distinguishing of saffron J. Laser Appl. (IF 1.41) Pub Date : 2020-07-23 Yuanzhe Zhangcheng; Yuzhu Liu; Seher Saleem; Qihang Zhang; Yu Chen; Yingfei Qu; Xu Lu
Laser-induced breakdown spectroscopy (LIBS) is a sensitive optical technique capable of rapid multielemental analysis. The development of this technique for elemental analysis in traditional Chinese medicine can eventually revolutionize the pharmaceutical industry. The detection and identification of real and fake elements in traditional Chinese medicine is very important, and saffron is a typical
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Machining of micrometer-scale high aspect ratio features with single femtosecond laser pulses J. Laser Appl. (IF 1.41) Pub Date : 2020-07-31 Brian K. Canfield; Lino Costa; Deepak Rajput; Alexander Terekhov; Kathleen Lansford; William H. Hofmeister; Lloyd M. Davis
The authors characterize femtosecond laser single-pulse machining of deep, micrometer-diameter holes and long, micrometer-width channels in fused silica by the use of spherical, cylindrical, and aspheric singlet lenses. Repositionable spherical lenses form an adjustable beam expander that also provides a means of minimizing—or deliberately introducing—spherical aberration (SA) in the focal region by
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Characterization of different light intensity areas for plasma induced during fiber laser-arc hybrid welding J. Laser Appl. (IF 1.41) Pub Date : 2020-08-11 Jianglin Zou; Shihui Guo; Lida Wang; Baoqi Zhu; Rongshi Xiao
In this paper, fiber laser-arc hybrid welding plasma was studied by using the multiple-imaging method. Four images of plasma with different light intensity areas can be simultaneously observed in a picture. The arc plasma and metal plasma can be distinguished in the high light intensity area, and the arc plasma has an approximate average light intensity distribution. The metal plasma is mainly concentrated
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Ultraviolet laser cleaning and surface characterization of AH36 steel for rust removal J. Laser Appl. (IF 1.41) Pub Date : 2020-08-12 Yao Lu; Ye Ding; Genwang Wang; LiJun Yang; Maolu Wang; Yang Wang; Bin Guo
Laser cleaning of rusted surfaces has broad applications in marine ship industrial manufacturing. An ultraviolet nanosecond laser cleaning method was proposed to strip the rust layer from the surface of the AH36 steel to reduce surface roughness and increase corrosion resistance. Multi-pulse laser ablation was established to determine the single-pulse threshold fluence and pulse incubation coefficient
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Application of semiconductor continuous and Nd:YAG pulsed laser processing for nondestructive cleaning of the historical paper J. Laser Appl. (IF 1.41) Pub Date : 2020-08-14 Sanja Petronic; Zoran Stevic; Silvana Dimitrijevic; Boris Rajcic; Dubravka Milovanovic
Preservation of cultural legacy is essential for ensuring its availability for future generations. Long-term indoor storage can sometimes cause the papers to adhere, which can result in the transfer of ink stamps or prints from paper to paper, and subsequently, there emerges the need to remove these types of stains. Laser cleaning emerged as a promising technique for paper surface cleaning. This work
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Rapid powder analysis with laser-induced breakdown spectroscopy at low pressure ambient helium gas employing bamboo charcoal as a sample holder J. Laser Appl. (IF 1.41) Pub Date : 2020-08-17 Ivan Tanra; Indra Karnadi; Marincan Pardede; Rinda Hedwig; Mangasi Alion Marpaung; Koo Hendrik Kurniawan; Kiichiro Kagawa
Several experiments are performed to explore the possible benefits of using bamboo charcoal as a sample holder for rapid powder analysis using laser-induced breakdown spectroscopy at low-pressure helium ambient gas. Standard powdered samples such as ZnS and CuSO4 are used to demonstrate the feasibility of using cheap and widely available bamboo charcoal as a sample holder. A commercial baby milk powder
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Analysis of overlapping rate of spot derived from ablated monocrystalline silicon by femtosecond laser J. Laser Appl. (IF 1.41) Pub Date : 2020-08-19 Fubin Wang; Mengzhu Liu; Paul Tu
In order to investigate the overlap rate of an ablated spot on monocrystalline silicon by a femtosecond laser, a skewness spot derived from plasma is analyzed. First, the serial spot image is collected, and the ablated core area of the spot is extracted by the way of bit image layering so that the peripheral halo can be eliminated effectively. The image of the spot is enhanced by Gaussian-guided filtering
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Validation of a generalized laser safety analysis method for irregular pulse trains J. Laser Appl. (IF 1.41) Pub Date : 2020-08-19 Mathieu Jean; Karl Schulmeister; Sebastian Kotzur; Annette Frederiksen
The current laser safety standards do not address specifically how to account for repetitively pulsed lasers with irregular pulse trains. Variations in peak power, pulse duration, and duty cycle within a pulse train pose a number of problems when it comes to product classification or to assess the hazard of a given exposure. This study proposes to analyze irregular pulse trains by generalizing the
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Multiwavelength diode array end-pumped, thermally stabilized, Nd:YAG pulsed laser J. Laser Appl. (IF 1.41) Pub Date : 2020-08-31 Yiheng Song; Xuesheng Liu; Song Yang; Jiyue Zou; Congcong Wang; Youqiang Liu; Anru Yan; Zhiyong Wang
An electro-optic Q-switched multiwavelength laser diode array end-pumped Nd:YAG laser without temperature control is proposed and demonstrated in this paper. Using a 3.2 kW multiwavelength laser diode array as the pump source, a lens duct as the coupling system, RTP crystals as the Q-switch, and an end-pumped Nd:YAG crystal rod (Ø 6 × 60 mm2) as the gain medium, the laser system obtained a maximum
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Influence of pressures in a hyperbaric environment on the penetration during pulsed laser welding of 304 stainless steels and its influence mechanism J. Laser Appl. (IF 1.41) Pub Date : 2020-08-31 Jian Long; Lin-Jie Zhang; Liang-Liang Zhang; Jie Ning; Xian-Qing Yin; Jian-Xun Zhang; Suck-Joo Na
Developing laser welding (LW) technology in a hyperbaric environment is significant for manufacturing and maintaining nuclear power facilities, offshore engineering structures, etc. However, the penetration is significantly reduced during LW in a hyperbaric environment, which has not been solved yet. Previous research has shown that compared with the penetration of LW in a hyperbaric argon (Ar) environment
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The influence of process parameters on corrosion behavior of Ti6Al4V alloy processed by selective laser melting J. Laser Appl. (IF 1.41) Pub Date : 2020-06-17 Chenghui Qian; Hongzhen Xu; Qun Zhong
Ti6Al4V alloy exhibits good biocompatibility and has a wide range of applications in the medical fields. Additive manufacturing, especially selective laser melting (SLM), provides a new and effective way for the fabrication of Ti6Al4V alloy biological components. The corrosion resistance of SLM processed Ti6Al4V alloy needs further investigation, which is important for the application of biological
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The effect of pre-heat temperature on the microstructure and abrasive wear properties of laser metal deposited near-eutectic Fe-28Cr-2.9C alloy J. Laser Appl. (IF 1.41) Pub Date : 2020-06-15 Shi D. Sun; Daniel Fabijanic; Murugesan Annasamy; Santiago Corujeira Gallo; Ian Fordyce; Martin Leary; Mark Easton; Milan Brandt
Fe-Cr-C near-eutectic alloys are commonly used in wear resistant parts in mining applications, due to their excellent erosion and abrasion wear resistance. Laser metal deposition is an additive technology that presents opportunities for manufacturing mining components, as well as repairing worn areas of wear resistant parts. However, Fe-Cr-C hypoeutectic alloys are very hard and brittle and are often
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Investigation on fiber laser irradiation of transparent polycarbonate J. Laser Appl. (IF 1.41) Pub Date : 2020-06-15 Guojie Chen; Z. K. Wang; Kok Keat Tan; Hong Xie; Xincai Wang
The study aims to understand the carbonization mechanism when an ns NIR transparent fiber laser beam irradiation of polycarbonate (PC) instead of irradiation using a UV laser beam or ultrashort pulsed laser beam. It reveals that PC can be decomposed with an ns transparent 1064 nm laser beam. The laser fluence threshold under which to cause ablation in PC was not a constant value. The threshold decreased
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Influence of wire feeding speed on the melting behavior and formation of narrow-gap joint by laser welding with filler wire J. Laser Appl. (IF 1.41) Pub Date : 2020-06-12 Jihong Pu; Yong Zhao; Yumo Jiang; Jiasheng Zou; Shuming Song
The influence of wire feeding speed during laser welding with a filling wire was investigated by high-speed imaging and mechanical analysis of the droplet. A force relationship was found to analyze the droplet transition behavior at the end of the welding wire in the narrow-gap groove. Welding defects, mainly including nonfusion and porosity, were studied to reveal the formation mechanism and propose
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Effects of geometrical size and structural feature on the shape-distortion behavior of hollow Ti-alloy blade fabricated by additive manufacturing process J. Laser Appl. (IF 1.41) Pub Date : 2020-06-08 Shuang Gao; Zhijun Tan; Liang Lan; Bo He
In the additive manufacturing (AM) process, metal powder can be directly used to produce metal components. Unfortunately, a large thermal gradient is developed during the AM process, which leads to the generation of residual stress and complex shape-distortions. In this study, the influence of the geometrical size and structural features of a hollow Ti-alloy blade prepared by the AM process on the
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Wettability modification of laser textured copper surfaces applied to phase change heat transfer J. Laser Appl. (IF 1.41) Pub Date : 2020-06-08 Caroline P. Martendal; Claudio A. Silveira; Milton Pereira; Marcio C. Fredel
Phase change heat transfer allows high heat transfer rates associated with small temperature variations. Given that this technique is employed in several energy and industry applications, such as automotive air-conditioning evaporators, pulsating heat pipes are used for aerospace thermal management and in semiconductor-manufacturing heat exchangers. Although phase change heat transfer has served mankind
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Keyhole mapping to enable closed-loop weld penetration depth control for remote laser welding of aluminum components using optical coherence tomography J. Laser Appl. (IF 1.41) Pub Date : 2020-06-03 Mikhail Sokolov; Pasquale Franciosa; Rehab Al Botros; Dariusz Ceglarek
Remote laser welding (RLW) combines the positive features of tactile laser welding with additional benefits such as increased processing speed, reduced operational cost and service, and higher process flexibility. A leading challenge preventing the full uptake of RLW technology in industry is the lack of efficient closed loop in-process (CLIP) monitoring and weld quality control solutions. This underpins
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Laser power influence on track’s geometry and microstructure aspects of Fe and Sn-based alloy processed by directed energy deposition J. Laser Appl. (IF 1.41) Pub Date : 2020-06-02 Gustavo Henrique Truppel; Marcelo Augusto Rosa; Milton Pereira; Paulo Antônio Pereira Wendhausen
Additive manufacturing of metal matrix composite (MMC) is a challenging field to explore. Besides components’ geometric constitution, requirements related to final microstructures must be met. Depending on the application, such as tribology, machining, or magnetism related, there is a need to preserve a specific phase, which is generally responsible for the engineering function of the fabricated component
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Precise laser structures as a tool to understand metal-polymer joints J. Laser Appl. (IF 1.41) Pub Date : 2020-06-02 Dominic Woitun; Michael Roderus; Thilo Bein; Elmar Kroner
Direct joining of metals and polymers is a promising approach for today’s challenges in joining technology due to fast cycling time, its robustness, and the absence of duroplastic adhesives. Laser pretreatment of the metallic surface has been proven to enhance joint strength and has become a popular method for joining hybrid components. However, the versatility of the laser process allows the generation
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Powder based laser material deposition on edges J. Laser Appl. (IF 1.41) Pub Date : 2020-06-01 Marie-Noemi Bold; Stefanie Linnenbrink; Norbert Pirch; Andrés Gasser; Jana Mund; Johannes Henrich Schleifenbaum
Powder based laser material deposition (LMD) is a suitable additive manufacturing technology for repair and overhaul of metal parts as well as for the build-up of new parts. This technology is used in industrial applications as automotive, turbomachinery, aviation, or tool making [T. Jambor, “Funktionalisierung von Bauteiloberflächen durch Mikro-Laserauftrag-schweißen,” Ph.D. thesis, RWTH Aachen University
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Real-time prediction of quality characteristics in laser beam welding using optical coherence tomography and machine learning J. Laser Appl. (IF 1.41) Pub Date : 2020-05-05 Christian Stadter, Maximilian Schmoeller, Lara von Rhein, Michael F. Zaeh
Laser beam welding significantly outperforms conventional joining techniques in terms of flexibility and productivity. The process benefits, in particular, from the highly focused energy and thus from a well-defined heat input. The high intensities of brilliant laser radiation, however, induce very dynamic effects and complex processes within the interaction zone. The high process dynamics require
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Ultrafast laser hybrid fabrication of hierarchical 3D structures of nanorods on microcones for superhydrophobic surfaces with excellent Cassie state stability and mechanical durability J. Laser Appl. (IF 1.41) Pub Date : 2020-05-05 Rui Pan, Mingyong Cai, Weijian Liu, Xiao Luo, Changhao Chen, Hongjun Zhang, Minlin Zhong
Superhydrophobic surfaces have been attracting considerable attention due to potential applications in self-cleaning, anti-icing, water/oil separation, drag reduction, water collection, etc. However, to date, except for a few textile surfaces and coating products, only a limited number of superhydrophobic applications have been commercialized. The main reasons for the limited number of applications
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Dissimilar laser cladding of Inconel 718 powder on A-286 substrate: Microstructural evolution J. Laser Appl. (IF 1.41) Pub Date : 2020-05-05 M. Alizadeh-Sh, S. P. H. Marashi, E. Ranjbarnodeh, R. Shoja-Razavi, J. P. Oliveira
In this work, laser cladding of a Ni-based superalloy powder (Inconel 718) on a Fe-based superalloy (A-286) substrate was performed. The microstructural evolution was studied by optical and electron microscopy techniques, aided by energy dispersive spectroscopy. Additionally, the microhardness along the as-deposited parts was analyzed and correlated with the observed microstructure. It was found that
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Observation of single ultrashort laser pulse generated periodic surface structures on linelike defects J. Laser Appl. (IF 1.41) Pub Date : 2020-05-05 Norbert Ackerl, Konrad Wegener
The formation of self-assembled laser induced periodic surface structures (LIPSSs) after ultrashort pulsed laser ablation is still a matter of controversy in the literature. There is agreement that at least two different physical driving forces lead to ripples with distinguishable spatial periodicity. High spatial frequency LIPSSs with periodicity well below the incident wavelength are discriminated
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Lamé curve approximation for the assessment of the 3D temperature distribution in keyhole mode welding processes J. Laser Appl. (IF 1.41) Pub Date : 2020-05-04 Antoni Artinov, Victor Karkhin, Nasim Bakir, Xiangmeng Meng, Marcel Bachmann, Andrey Gumenyuk, Michael Rethmeier
A novel approach for the reconstruction of an equivalent volumetric heat source from a known weld pool shape is proposed. It is based on previously obtained weld pool geometries from a steady-state thermo-fluid dynamics simulation. Hereby, the weld pool dimensions are obtained under consideration of the most crucial physical phenomena, such as phase transformations, thermo-capillary convection, natural
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Experimental research of picosecond laser based edge preparation of cutting tools J. Laser Appl. (IF 1.41) Pub Date : 2020-05-04 Yiyun Kang, Hicham Derouach, Niklas Berger, Thomas Herrmann, Johannes L’huillier
In this study, using ultrafast lasers of 10 ps pulse duration as a precise and efficient method for cutting edge preparation is researched. Cutting edge preparation is an important step within cutting tool manufacturing, while unprepared sharp cutting edges show low stability, which leads to tool failure by high mechanical and thermal loads during the turning processes [C. F. Wyen, W. Knapp, and K
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Absorption and temperature distribution during ultrafast laser microcutting of polymeric materials J. Laser Appl. (IF 1.41) Pub Date : 2020-05-04 Arifur Rahaman, Xinpeng Du, Boyang Zhou, He Cheng, Aravinda Kar, Xiaoming Yu
Material processing by ultrafast lasers is an attractive technology for high-precision fabrication, such as cutting, drilling, and surface modification, of a wide range of material, including dielectrics, semiconductor, metals, and polymer composites. However, it is still challenging to apply ultrafast laser processing in many applications because some key processes, such as absorption and heat accumulation
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Influence of laser metal deposition direction in the abrasive and adhesive wear resistance of Ni-Cr-B-Si coatings J. Laser Appl. (IF 1.41) Pub Date : 2020-05-04 Jurandir Marcos Sá de Sousa, Adriano de Souza Pinto Pereira, Milton Pereira, Rafael Gomes Nunes Silva
Problems related to component wear are one of the biggest challenges faced by industrial sectors such as agriculture, mining, and oil and gas. Coating application has been a good alternative to mitigate these problems. Ni-Cr-B-Si alloys are recognized for their abrasion and adhesion resistance properties. In this context, a comparison between the mechanical wear of Ni-Cr-B-Si 1545-00 deposited via
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Study on surface morphology and recast layer microstructure of medium thickness stainless steel sheets using high power laser cutting J. Laser Appl. (IF 1.41) Pub Date : 2020-04-30 Chongjing Hu, Gaoyang Mi, Chunming Wang
With the rapid development of high-power lasers, efficiency of laser cutting and thickness of cutting material have been greatly increased. In this study, a 10 kW fiber laser was used to cut 18 mm thick 316L stainless steel sheets. The surfaces and cross sections of samples were observed by an optical microscope and a scanning electron microscope. It was found that the quality of laser cutting was
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Tribological comparison of Inconel 625 coatings deposited via laser metal deposition and tungsten inert gas welding process J. Laser Appl. (IF 1.41) Pub Date : 2020-04-30 Rafael Gomes Nunes Silva, Adriano de Souza Pinto Pereira, Jurandir Marcos Sá de Sousa, Milton Pereira, Régis Henrique Gonçalves e Silva
Although different forms of renewable energy sources are in expansion, the oil and natural gas industry remains essential, maintaining its demand for more efficient methods for product transportation. The most productive and safe way is the flow through pipelines. However, pipeline usage directly involves several wear mechanisms, which contribute to pipeline degradation and, consequently, the need
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Electric evaluation of hybrid laser-TIG welding: Interaction between arc and laser plume J. Laser Appl. (IF 1.41) Pub Date : 2020-04-30 Rafael Gomes Nunes Silva, Milton Pereira, Max Baranenko Rodrigues, Adriano de Souza Pinto Pereira, Mateus Barancelli Schwedersky
Hybrid laser-arc welding (HLAW) is regarded as a promising joining process, since it can compensate disadvantages from laser autogenous welding and arc welding by uniting both techniques into a single melt pool. Such a process can achieve relative high quality metallurgical bonding, high speed, and low deformation. However, the process is considered complex and of difficult parametrization, as the
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