Zefeng Wu, P. O’Toole, C. Hagenlocher, M. Qian, Milan Brandt, Jarrod Watts
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.
{"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":"113 1","pages":""},"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}
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.
激光焊接过程中的锁孔和熔池形态与焊缝成形过程密切相关，并进一步影响焊缝质量。为了研究振荡振幅对异种材料 T 型接头振荡激光桩焊接过程中键孔和熔池形态演变过程的影响，建立了一个三维多相流数值模型。详细计算并分析了不同振幅下异种材料 T 型接头的圆形振荡激光桩焊接过程。结果表明，在异种材料 T 型接头的圆弧形振荡激光桩焊接过程中，随着振荡振幅的增大，键孔深度减小，熔池宽度和界面焊缝宽度增大。焊接过程中会形成键孔的周期性膨胀和收缩。由于键孔的不稳定性，键孔的塌陷可能会在熔池中产生气泡，这些气泡随后也会被键孔捕获。
{"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":"22 1","pages":""},"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}
A fundamental understanding of ablation in different incidence angles is indispensable to expand the result to volume ablation where nonperpendicular irradiation exists. So far, no study with this orientation has been conducted in the category of volume laser machining. In this study, a nanosecond laser with different fluencies was utilized for single-point ablation experiments. The effect of incidence angles of 0°, 30°, and 60° on the ablation depth and the crater geometry was evaluated. Different laser pulse numbers are also considered. The results show that the ablation depth for 0° and 30° angles is almost in the same range for the initial pulses, but afterward, the ablation depth for the incidence 30° drops considerably. As the number of incident pulses increases, the ablation depth first develops approximately linearly and then grows exponentially. By changing the incident from 0° to 60°, the affecting area changes as well. The affecting area could be categorized into two distinct areas: (1) ablation area (A.A) where the crater ablation depth rapidly increases for the first 20 pulses and then, as more incident pulses arrive, it does not grow anymore and reaches a plateau due to the increase in the ablation depth. The second area (2) is the heat-affected area (H.A.A) of the crater where no further ablation occurs, but due to heat accumulation, it becomes constantly bigger when more incident pulses strike the crater. This heat-affected area tends to stay almost constant for the first incident pulses (up to 10) and, after a sharp increase, tends to enlarge steadily as the number of incident pulses rises to 70.
{"title":"Investigation of NS-single-point laser ablation of bronze under different incidence angles and pulses","authors":"Esmaeil Ghadiri Zahrani, Bahman Azarhoushang","doi":"10.2351/7.0001146","DOIUrl":"https://doi.org/10.2351/7.0001146","url":null,"abstract":"A fundamental understanding of ablation in different incidence angles is indispensable to expand the result to volume ablation where nonperpendicular irradiation exists. So far, no study with this orientation has been conducted in the category of volume laser machining. In this study, a nanosecond laser with different fluencies was utilized for single-point ablation experiments. The effect of incidence angles of 0°, 30°, and 60° on the ablation depth and the crater geometry was evaluated. Different laser pulse numbers are also considered. The results show that the ablation depth for 0° and 30° angles is almost in the same range for the initial pulses, but afterward, the ablation depth for the incidence 30° drops considerably. As the number of incident pulses increases, the ablation depth first develops approximately linearly and then grows exponentially. By changing the incident from 0° to 60°, the affecting area changes as well. The affecting area could be categorized into two distinct areas: (1) ablation area (A.A) where the crater ablation depth rapidly increases for the first 20 pulses and then, as more incident pulses arrive, it does not grow anymore and reaches a plateau due to the increase in the ablation depth. The second area (2) is the heat-affected area (H.A.A) of the crater where no further ablation occurs, but due to heat accumulation, it becomes constantly bigger when more incident pulses strike the crater. This heat-affected area tends to stay almost constant for the first incident pulses (up to 10) and, after a sharp increase, tends to enlarge steadily as the number of incident pulses rises to 70.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":"56 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139303161","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}
M. Kardan, N. Levichev, Sylvie Castagne, Joost R. Duflou
Cutting thick plates is affected not only by the laser power but also by the cut kerf width and the melt flow dynamics that determine the ejection of the molten material. Employing the same laser beam intensity distribution for various thicknesses is the limiting factor when cutting thicker plates. This paper investigates fiber laser fusion cutting of 25 mm thick aluminum with dynamic beam shaping (DBS). While both static and longitudinal dynamic intensity distributions fail to cut this thickness with a 4 kW laser power, a cut through is achieved using annular and elliptical intensity distributions. However, an improvement of 45% in cutting speed can be achieved using an elliptical intensity distribution compared to an annular one. In order to understand the effect of the beam shape, an infrared thermal camera is used to study lateral heat propagation when using different process parameters. Moreover, to analyze the melt flow when changing the DBS frequency, high-speed imaging is utilized to observe the molten material inside the cut kerf. Finally, the cut edge quality is investigated for different cutting conditions.
{"title":"Cutting thick aluminum plates using laser fusion cutting enhanced by dynamic beam shaping","authors":"M. Kardan, N. Levichev, Sylvie Castagne, Joost R. Duflou","doi":"10.2351/7.0001095","DOIUrl":"https://doi.org/10.2351/7.0001095","url":null,"abstract":"Cutting thick plates is affected not only by the laser power but also by the cut kerf width and the melt flow dynamics that determine the ejection of the molten material. Employing the same laser beam intensity distribution for various thicknesses is the limiting factor when cutting thicker plates. This paper investigates fiber laser fusion cutting of 25 mm thick aluminum with dynamic beam shaping (DBS). While both static and longitudinal dynamic intensity distributions fail to cut this thickness with a 4 kW laser power, a cut through is achieved using annular and elliptical intensity distributions. However, an improvement of 45% in cutting speed can be achieved using an elliptical intensity distribution compared to an annular one. In order to understand the effect of the beam shape, an infrared thermal camera is used to study lateral heat propagation when using different process parameters. Moreover, to analyze the melt flow when changing the DBS frequency, high-speed imaging is utilized to observe the molten material inside the cut kerf. Finally, the cut edge quality is investigated for different cutting conditions.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":"64 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139304939","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}
Malte Schmidt, Knut Partes, Rohan Rajput, Giorgi Phochkhua, Henry Köhler
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.
{"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":"36 2","pages":"0"},"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}
Tim Röver, Maximilian Bader, Karim Asami, Claus Emmelmann, Ingomar Kelbassa
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.
{"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":"55 9","pages":"0"},"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}
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.
{"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":"14 4","pages":"0"},"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}
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.
{"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":"36 10","pages":"0"},"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}
Cemented carbide (WC-Co), the widely used tool-die material, is difficult to be machined by conventional and nonconventional techniques. This inspired exploring additive manufacturing (AM) of this material. However, porosity, brittleness due to cobalt depletion, etc. have been reported in the literature with rare success. For the AM of WC-Co, the current work focuses on directed energy deposition, which can be implemented with existing laser cutting-welding workstations, with modifications. To ensure the retention of cobalt even after inevitable vaporization of some of its initial content during deposition, 20 wt. % of Co was mixed with WC powder by low-energy ball milling. Laser power, scan speed, and powder flow rate were varied following a full-factorial design of experiments. The analysis of variance revealed that the experimental model and most of the parameters were significant. Only the laser power came out to be insignificant for the contact angle. The track height and width increased with the laser power and reduced with the scan speed. The contact angle increased with the scan speed and reduced with the powder flow rate. Cross sections of the deposited track showed no pores or cracks. Multiobjective optimization with gray relational analysis was conducted to get the parameter combination giving high values of the contact angle, track height, and width simultaneously. The optimum parameter combination, thus, obtained is 700 W laser power, 5 mm/s scan speed, and 5 g/min powder flow rate. This yielded 305 ± 40 μm track height, 2132 ± 33 μm width, and 152° ± 2° contact angle.
{"title":"Parametric investigation and optimization in laser based directed energy deposition of tungsten carbide-cobalt","authors":"Ankit Shrivastava, Anirban Changdar, Abhijit Datta, Samik Dutta, Shitanshu Shekhar Chakraborty","doi":"10.2351/7.0001179","DOIUrl":"https://doi.org/10.2351/7.0001179","url":null,"abstract":"Cemented carbide (WC-Co), the widely used tool-die material, is difficult to be machined by conventional and nonconventional techniques. This inspired exploring additive manufacturing (AM) of this material. However, porosity, brittleness due to cobalt depletion, etc. have been reported in the literature with rare success. For the AM of WC-Co, the current work focuses on directed energy deposition, which can be implemented with existing laser cutting-welding workstations, with modifications. To ensure the retention of cobalt even after inevitable vaporization of some of its initial content during deposition, 20 wt. % of Co was mixed with WC powder by low-energy ball milling. Laser power, scan speed, and powder flow rate were varied following a full-factorial design of experiments. The analysis of variance revealed that the experimental model and most of the parameters were significant. Only the laser power came out to be insignificant for the contact angle. The track height and width increased with the laser power and reduced with the scan speed. The contact angle increased with the scan speed and reduced with the powder flow rate. Cross sections of the deposited track showed no pores or cracks. Multiobjective optimization with gray relational analysis was conducted to get the parameter combination giving high values of the contact angle, track height, and width simultaneously. The optimum parameter combination, thus, obtained is 700 W laser power, 5 mm/s scan speed, and 5 g/min powder flow rate. This yielded 305 ± 40 μm track height, 2132 ± 33 μm width, and 152° ± 2° contact angle.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":"19 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135410350","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}
J. M. Sánchez-Amaya, A. Gómez-Parra, C. Churiaque, S. R. Fernández-Vidal, A. J. Gámez
In the present research, the hybrid laser arc welding (HLAW) process has been applied to join 8 mm thick structural S355J2N steel under 1G configuration. Welding tests were performed at the Laser Welding Advanced Center available at the University of Cadiz, Spain. Different experimental welding parameters were fitted to obtain sound butt welds. The welds were subjected to different quality control tests, including visual inspection, metallographic characterization, microhardness measurements, and tensile and fatigue tests. The HLAW tests were performed at higher welding rates in 1G configuration than previously reported for 8 mm thick steels. Complete penetration was achieved in all welds, presenting suitable geometries without defects such as cracks, root humps, or porosities. Microhardness values measured at different welding zones were always below 350 HV. All welds broke at the base metal in the tensile tests. The present contribution reports novel fatigue results for these butt hybrid welds. The samples welded at the highest welding rate (2.5 m/min) were the ones providing the best fatigue response, due to the lower heat input applied under this condition.
{"title":"Fatigue behavior of <scp>8 </scp>mm thick steel butt joints performed with hybrid laser arc welding","authors":"J. M. Sánchez-Amaya, A. Gómez-Parra, C. Churiaque, S. R. Fernández-Vidal, A. J. Gámez","doi":"10.2351/7.0001084","DOIUrl":"https://doi.org/10.2351/7.0001084","url":null,"abstract":"In the present research, the hybrid laser arc welding (HLAW) process has been applied to join 8 mm thick structural S355J2N steel under 1G configuration. Welding tests were performed at the Laser Welding Advanced Center available at the University of Cadiz, Spain. Different experimental welding parameters were fitted to obtain sound butt welds. The welds were subjected to different quality control tests, including visual inspection, metallographic characterization, microhardness measurements, and tensile and fatigue tests. The HLAW tests were performed at higher welding rates in 1G configuration than previously reported for 8 mm thick steels. Complete penetration was achieved in all welds, presenting suitable geometries without defects such as cracks, root humps, or porosities. Microhardness values measured at different welding zones were always below 350 HV. All welds broke at the base metal in the tensile tests. The present contribution reports novel fatigue results for these butt hybrid welds. The samples welded at the highest welding rate (2.5 m/min) were the ones providing the best fatigue response, due to the lower heat input applied under this condition.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":"81 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135515073","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}
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