Journal of Laser Applications最新文献

{"title":"Antibacterial effect of periodic structure formed on SUS430 by using nanosecond pulsed laser","authors":"Mikuru Okazaki, Masaki Hashida, Satoru Iwamori","doi":"10.2351/7.0001196","DOIUrl":"https://doi.org/10.2351/7.0001196","url":null,"abstract":"We investigated the laser-induced periodic surface structures (LIPSSs) formed on an SUS430 surface by irradiation with a nanosecond pulsed laser (Nd:YAG, wavelength of 532 nm, pulse width of 10 ns, number of pulses of 50, repetition rate of 10 Hz, and laser fluence of 1.2 J/cm2) and the antibacterial effect of the surface. LIPSSs with an interspacing of about 500 nm, which was close to the laser wavelength, were produced on the surface when the pulsed laser was near the ablation threshold. The film attachment method (JIS Z 2801) was used to measure the bacterial growth suppression on SUS430 surfaces with and without LIPSSs. On the surface without an LIPSS, the number of colonies was 1244, and on that with an LIPSS, the number was 198, indicating that the LIPSS formed by nanosecond pulsed laser irradiation inhibited the growth of bacteria. The chrome oxide layer on the SUS430 surface with the LIPSS may emit chrome ions from the edge of the LIPSS, enhancing the antibacterial effect.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139295544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Automated quality evaluation for laser cutting in lithium metal battery production using an instance segmentation convolutional neural network","authors":"J. Kriegler, Tianran Liu, R. Hartl, Lucas Hille, M. F. Zaeh","doi":"10.2351/7.0001213","DOIUrl":"https://doi.org/10.2351/7.0001213","url":null,"abstract":"Separating lithium metal foil into individual anodes is a critical process step in all-solid-state battery production. With the use of nanosecond-pulsed laser cutting, a characteristic quality-decisive cut edge geometry is formed depending on the chosen parameter set. This cut edge can be characterized by micrometer-scale imaging techniques such as confocal laser scanning microscopy. Currently, experimental determination of suitable process parameters is time-consuming and biased by the human measurement approach, while no methods for automated quality assurance are known. This study presents a deep-learning computer vision approach for geometry characterization of lithium foil laser cut edges. The convolutional neural network architecture Mask R-CNN was implemented and applied for categorizing confocal laser scanning microscopy images showing defective and successful cuts, achieving a classification precision of more than 95%. The algorithm was trained for automatic pixel-wise segmentation of the quality-relevant melt superelevation along the cut edge, reaching segmentation accuracies of up to 88%. Influence of the training data set size on the classification and segmentation accuracies was assessed confirming the algorithm’s industrial application potential due to the low number of 246 or fewer original images required. The segmentation masks were combined with topography data of cut edges to obtain quantitative metrics for the quality evaluation of lithium metal electrodes. The presented computer vision pipeline enables the integration of an automated image evaluation for quality inspection of lithium foil laser cutting, promoting industrial production of all-solid-state batteries with lithium metal anode.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139297799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Melt pool dynamics on different substrate materials in high-speed laser directed energy deposition process","authors":"Zefeng Wu, P. O’Toole, C. Hagenlocher, M. Qian, Milan Brandt, Jarrod Watts","doi":"10.2351/7.0001145","DOIUrl":"https://doi.org/10.2351/7.0001145","url":null,"abstract":"High-speed laser directed energy deposition (HSL-DED) is a variant of the laser directed energy deposition process where a defocused metal powder stream is used, and it typically involves processing speeds exceeding 5 m/min. However, the interactions between the laser beam, powder stream, and substrate surface in HSL-DED have not been extensively studied. This study used a specialized XIRIS XVC-1000 welding camera with a narrow bandpass filter to record the interaction phenomenon. These observations were first carried out without powder delivery, using laser surface melting techniques, and involved processing speeds of up to 20 m/min and laser powers of up to 3 kW. HSL-DED with powder delivery was then conducted with the same parameter combinations for comparative analysis. The in situ observations in laser surface melting and HSL-DED identified a physical separation between the laser spot and the melt pool boundary, referred to as melt pool lag. Different substrates’ chemical compositions and the resulting thermophysical properties significantly impact melt pool dynamics during the high-speed laser-material interactions for a given process condition. The findings from this work have enabled a better understanding and control of melt pool dynamics in HSL-DED.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139305973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Process development and process adaption guidelines for the deposition of thin-walled structures with IN718 using extreme high-speed directed energy deposition (EHLA3D)","authors":"Min-Uh Ko, Zongwei Zhang, Thomas Schopphoven","doi":"10.2351/7.0001140","DOIUrl":"https://doi.org/10.2351/7.0001140","url":null,"abstract":"Extreme high-speed directed energy deposition (EHLA) is a modified variant of the laser based directed energy deposition (DED-LB) and is being applied as an efficient coating process for rotational symmetric components. Characteristics of EHLA processes are feed rates of up to 200 m/min, which result in smaller weld bead deposition and thinner layer thicknesses compared to conventional DED-LB. When transferred to additive manufacturing, this characteristic utilizes the potential of depositing thin-walled filigree structures at deposition rates, which are comparable to typical DED-LB processes (EHLA3D). The results of this work were achieved with an EHLA3D machine, which is a modified CNC-type machine capable of operating feed rates with vf = 30 m/min. In this work, process parameters were developed for the deposition of thin-walled filigree structures with the Ni-based superalloy IN718. Single tracks with constant feed rates and a variation in the beam diameter and powder mass flow were deposited and analyzed regarding the resulting weld bead dimension and dilution zone. Then, process parameters were selected and transferred to the deposition of thin walls, and guidelines of the parameter adaption toward thin-walled deposition were defined. Two parameter sets were developed to assess the feasible wall-thicknesses deposited by EHLA3D. Depending on the developed parameter sets, wall thicknesses between 300 and 500 μm are achieved. To characterize the resulting thin-walls, surface roughness measurements and metallographic cross sections were conducted.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135371116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling and multiobjective optimization of thermal effects of fiber laser cutting of Inconel 600 sheet by employing the ANN and multi-objective PSO algorithm","authors":"Mohammad Hossein Razavi Dehkordi, Dheyaa J. Jasim, Ameer H. Al-Rubaye, Mohammad Akbari, Seyed Amin Bagherzadeh, Mohammadreza Ghazi, Hamed Mohammadkarimi","doi":"10.2351/7.0001231","DOIUrl":"https://doi.org/10.2351/7.0001231","url":null,"abstract":"In this study, the experimental results of fiber laser cutting of Inconel 600 was modeled and optimized by combining artificial neural networks (ANNs) and particle swarm optimization (PSO). The impact of cutting criteria on the temperature adjacent to the cut kerf and roughness of the cutting edge was experimentally evaluated. The independent variables are the cutting speed, focal length, and laser power. The fiber laser cutting characteristics are modeled at different cutting conditions by the ANN method according to the experimental data. The findings indicated that the ANN is performing reasonably well in dealing with the training and test datasets. Also, the multiobjective PSO has been developed to effectively optimize the laser cutting procedure parameters in order to achieve the maximum temperature (the temperature upper than 370 °C) and minimum roughness (lower than 3 μm) simultaneously in order to improve the laser cutting efficiency. Based on the PSO results, the optimal laser power gained at a laser power of 830 and 1080 W at cutting speed ranges from 2 to 4 m/min and maximum focal length ranges between 0.75 and 0.8 mm where the lowest amount of roughness was created. The optimum temperature ranges were between 370 and 419°C. At a laser power of 1000 W and speed of 4 m/min, the smooth cutting edge at minimum roughness was gained without any defects. Transmission of the focal point up to 1.5 mm below the top surface of the sheet improved the roughness of the cutting edge and the cut quality by producing the smooth surface without slags.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135372163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of influence of oscillation amplitude on keyhole and molten pool morphologies during oscillating laser stake welding of dissimilar materials T-joints","authors":"Yuewei Ai, Jiabao Liu, Shibo Han","doi":"10.2351/7.0001132","DOIUrl":"https://doi.org/10.2351/7.0001132","url":null,"abstract":"The morphologies of the keyhole and molten pool during the laser welding process are highly related to weld formation process, which affects the weld quality further. To investigate the influence of the oscillation amplitude on the morphology evolution processes of the keyhole and molten pool during the oscillating laser stake welding of dissimilar materials T-joints, a three-dimensional multiphase flow numerical model is developed. The circular shaped oscillating laser stake welding processes of dissimilar materials T-joints under different oscillation amplitudes are calculated and analyzed in detail. The results show that the depth of the keyhole decreases and the widths of the molten pool and weld at the interface increase with the increase in the oscillation amplitude during the circular shaped oscillating laser stake welding of dissimilar materials T-joints. The periodical expansion and contraction of the keyhole are formed during the welding process. The collapse of the keyhole may cause bubbles in the molten pool due to the instability of the keyhole, and these bubbles also can be captured by the keyhole later.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139291963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring the degree of dilution during directed energy deposition of aluminum bronze and H13 tool steel using optical emission spectroscopy","authors":"Malte Schmidt, Knut Partes, Rohan Rajput, Giorgi Phochkhua, Henry Köhler","doi":"10.2351/7.0001081","DOIUrl":"https://doi.org/10.2351/7.0001081","url":null,"abstract":"Controlling heat transfer in casting tools is a key quality aspect. It can be improved by selectively applying volumetric aluminum bronze (CuAl9.5Fe1.2) sections in the core of the tools and subsequently depositing these cores with hard-facing H13 tool steel. Directed energy deposition (DED) can be used for both additive manufacturing of aluminum bronze and hard-facing by depositing the filler material onto a substrate surface or previously manufactured bodies. A sufficient metallurgical bonding of the deposited filler material and the underlying layer must be ensured. Hence, the dilution is a key factor for quality assurance. However, high dilution of the underlying layer and the filler material negatively affects the desired properties and must be monitored. Optical emission spectroscopy of the DED process emissions is investigated by comparing the emission lines of the individual elements comprising the base and the filler materials. Multiple single tracks using aluminum bronze as the filler material are laser-cladded with varying power, onto the two different types of substrates, i.e., mild steel S355 (1.0570) and hot working tool steel H11 (1.2343). Additionally, single tracks of H13 (1.2344) are deposited with varying laser powers onto an additively manufactured core of aluminum bronze. Both resulting in deposition tracks with varying dilution values. Multiple emission lines of Cr, Fe, Cu, Al, and Mn are detected and measured (line intensity). Line intensity ratios using the element emission lines are calculated and correlated with the respective metallographic results of the deposition tracks (dilution and chemical composition). Deposition tracks with a higher dilution (CuAl9.5Fe1.2 onto S355/H11 as well as H13 onto CuAl9.5Fe1.2) showed an increased line intensity ratio of the underlying material to the filler material. Moreover, this technology was transferred in a multilayer industrial application.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135372169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface wettability patterning of metal additive manufactured parts via laser-assisted functionalization","authors":"Wuji Huang, Ben Nelson, Hongtao Ding","doi":"10.2351/7.0001143","DOIUrl":"https://doi.org/10.2351/7.0001143","url":null,"abstract":"Additive manufacturing (AM) has revolutionized the production of complex geometries with superior properties compared with traditional manufacturing methods. However, the high roughness and poor wettability of as-produced surfaces of AM parts limit their suitability for certain applications. To address this, we present a maskless laser-assisted surface functionalization method to improve the wettability of metal 3D printed parts. This study explores the potential of combining metal AM with surface wettability patterning, a promising technique in fluid-related fields. Large-area AlSi10Mg parts were fabricated using laser powder bed fusion (L-PBF), followed by an innovative laser-assisted functionalization (LAF) method to achieve patterned wetting surfaces. The LAF method consists of laser texturing and chemical modification steps, and two strategies were demonstrated to fabricate different types of wettability patterns. Strategy I helps produce two types of superhydrophobicity, while strategy II helps create a superhydrophobic-superhydrophilic patterned surface. The study demonstrates the simplicity, robustness, and feasibility of the process and analyzes the processing mechanism, surface topography, and surface chemistry. The integration of surface wettability patterning and 3D-printing can optimize components to enhance performance and efficiency by creating intricate fluid flow pathways. Overall, this work highlights the potential of combining metal AM with surface wettability patterning, providing a pathway to produce high-performance parts with tailored wettability properties. This research has significant implications for fluid-related industries such as aerospace, automotive, and energy, as it offers unparalleled design freedom and the ability to create complex geometries.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135565145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and assessment of a methodology for abstraction of topology optimization results to enable the substitution of optimized beams","authors":"Tim Röver, Maximilian Bader, Karim Asami, Claus Emmelmann, Ingomar Kelbassa","doi":"10.2351/7.0001185","DOIUrl":"https://doi.org/10.2351/7.0001185","url":null,"abstract":"Improving mechanical topology optimization (TO) results by substituting biomimetic beams is one possibility to achieve designs of mechanical components that are highly sustainable and show good mechanical performance. Because of their geometric complexity, such designs were found to be well-suited for production by laser additive manufacturing. One obstacle of incorporating biomimetics beams in TO designs is the lack of detailed design methodologies. Röver et al. [“Methodology for integrating biomimetic beams in abstracted topology optimization results,” in Proceedings of the ASME 2022 International Mechanical Engineering Congress and Exposition. Volume 4: Biomedical and Biotechnology; Design, Systems, and Complexity Columbus, OH, 30 October–3 November (ASME, New York, 2022)] proposed a corresponding design concept. Building on their concept, we present in this work a detailed methodology for abstraction of TO results to a design consisting of ball nodes and cylindrical beams. Using such an auxiliary design, the internal forces and moments of the beams can be evaluated to allow for the substitution of suitable biomimetic beams to generate biomimetic component designs in a next step. We present a skeletonization algorithm based on the potential field approach. Using the skeletonization and an additional analysis of the dimensions of the beams in the TO result, the algorithm develops an auxiliary design of the original TO result. The final algorithm was applied to three common TO results to obtain one auxiliary component design each. The developed algorithm was found to generate abstractions that were well-suited for use in the methodology proposed in Röver et al. [“Methodology for integrating biomimetic beams in abstracted topology optimization results,” in Proceedings of the ASME 2022 International Mechanical Engineering Congress and Exposition. Volume 4: Biomedical and Biotechnology; Design, Systems, and Complexity Columbus, OH, 30 October–3 November (ASME, New York, 2022)], because internal forces and moments in the abstracted beams could be evaluated with less effort. Therefore, our work contributes to a detailed design methodology for biomimetic mechanical components in the field of design for additive manufacturing.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135410159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High speed laser cutting of ultrathin metal foils for battery cell production","authors":"Alessandro Ascari, Caterina Angeloni, Erica Liverani, Alessandro Fortunato","doi":"10.2351/7.0001091","DOIUrl":"https://doi.org/10.2351/7.0001091","url":null,"abstract":"Laser-based manufacturing has become a key enabling technology in the production of batteries and battery cells for the e-mobility field. Several applications, in fact, have already been industrialized, such as laser-based welding, cutting, stripping, and cleaning. Among all those technologies, laser cutting, in particular, has to deal with several very stringent constraints: the presence of highly reflective materials (aluminum and copper), very low thicknesses (6–12 μm), on-the-fly processing, and high quality of the cutting surface. According to those considerations, the present paper deals with the application of remote cutting of 12 μm thick aluminum and 6 μm thick copper foils by means of a galvo scanner and two different fiber laser sources: single mode constant wave and nanosecond pulsed wave ones. The experimental activity is devoted to understanding the feasibility of the process and to point out the pros and cons of the two different lasers involved. The cutting edges are analyzed by means of optical and SEM microscopy, in order to characterize cutting quality. The process is also characterized in terms of maximum achievable speed in order to understand the limits of both lasers and galvo scanning systems.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135410356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}