To develop high-performance medical alloy coatings that can reduce the risk of postoperative infection, TiZrNbCux refractory medium-entropy alloy (RMEA) coatings are designed and prepared on the Ti6Al4V alloy. The effects of varying Cu additions on the microstructure, micro/nano-hardness, elastic modulus, wear resistance, corrosion resistance, and antibacterial properties are investigated. The microstructure reveals that the RMEA coatings comprise body-centered-cubic dendrites and an Mo2Si-type interdendritic (Ti, Zr)2Cu phase. Also, the contents and dimensions of (Ti, Zr)2Cu gradually increase with the increasing Cu contents. The increased amounts of Cu atoms are beneficial for the improvement of hardness and elastic modulus, but contribute little to wear resistance. Meanwhile, the electrochemical polarization curve reflects that Cu-containing RMEA coatings show superior corrosion resistance. The antibacterial test on the Cu0.1 RMEA coating demonstrates a 99.95% antibacterial rate against S. aureus after coculturing for 18 h, indicating its novel antibacterial property. Thus, TiZrNbCux RMEA coatings present huge potential in medical applications for implants.
{"title":"Laser direct forming submicron Cu-rich particle structural TiZrNbCux medium-entropy alloy coatings to achieve desirable anti-bacterial property","authors":"Junfeng Wang, Yaxiong Guo, Jiawang Wu, Fangping Wang, Xiaojuan Shang, Jing Zhang, Qibin Liu","doi":"10.2351/7.0001229","DOIUrl":"https://doi.org/10.2351/7.0001229","url":null,"abstract":"To develop high-performance medical alloy coatings that can reduce the risk of postoperative infection, TiZrNbCux refractory medium-entropy alloy (RMEA) coatings are designed and prepared on the Ti6Al4V alloy. The effects of varying Cu additions on the microstructure, micro/nano-hardness, elastic modulus, wear resistance, corrosion resistance, and antibacterial properties are investigated. The microstructure reveals that the RMEA coatings comprise body-centered-cubic dendrites and an Mo2Si-type interdendritic (Ti, Zr)2Cu phase. Also, the contents and dimensions of (Ti, Zr)2Cu gradually increase with the increasing Cu contents. The increased amounts of Cu atoms are beneficial for the improvement of hardness and elastic modulus, but contribute little to wear resistance. Meanwhile, the electrochemical polarization curve reflects that Cu-containing RMEA coatings show superior corrosion resistance. The antibacterial test on the Cu0.1 RMEA coating demonstrates a 99.95% antibacterial rate against S. aureus after coculturing for 18 h, indicating its novel antibacterial property. Thus, TiZrNbCux RMEA coatings present huge potential in medical applications for implants.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140248214","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}
By preparing the 18Ni300 laser clad layers at different energy densities, the pores of the laser clad layers were measured and analyzed by using the image method, and the effect of energy density on the porosity was explored by combining the experimental data. The experimental results show that the cross-sectional pores of the laser clad layers are regular in shape and do not intersect with each other, and most of the pores are gathered at the top edge of the fused cladding layer. The influence of process parameters on the morphology of the laser clad layer is obvious. The study shows that the influence of process parameters on porosity is in the order of laser power, scanning speed, and powder feeding voltage; combined with the analysis of variance table and response surface diagram, the interaction between the parameters is obvious, and combined with the change, it can achieve the purpose of reducing porosity. Porosity first increases and then decreases with the increase in the energy density, and the distribution of the energy density and porosity is divided into regions, and larger porosity can be avoided by selecting the regions. The hardness of the laser clad layer can be increased by the choice of energy density. The laser clad layer with good test results was observed to contain Co, α-Fe, and Fe7Ni3 intermetallic compounds. The microstructure is transformed from fine grains at the top to columnar dendrites at the bottom.
{"title":"Effect of energy density on quality and properties of 18Ni300 laser clad layers by laser cladding","authors":"Weimin Li, Zeyu Yang, Qi Gao, Shufen Liu","doi":"10.2351/7.0001240","DOIUrl":"https://doi.org/10.2351/7.0001240","url":null,"abstract":"By preparing the 18Ni300 laser clad layers at different energy densities, the pores of the laser clad layers were measured and analyzed by using the image method, and the effect of energy density on the porosity was explored by combining the experimental data. The experimental results show that the cross-sectional pores of the laser clad layers are regular in shape and do not intersect with each other, and most of the pores are gathered at the top edge of the fused cladding layer. The influence of process parameters on the morphology of the laser clad layer is obvious. The study shows that the influence of process parameters on porosity is in the order of laser power, scanning speed, and powder feeding voltage; combined with the analysis of variance table and response surface diagram, the interaction between the parameters is obvious, and combined with the change, it can achieve the purpose of reducing porosity. Porosity first increases and then decreases with the increase in the energy density, and the distribution of the energy density and porosity is divided into regions, and larger porosity can be avoided by selecting the regions. The hardness of the laser clad layer can be increased by the choice of energy density. The laser clad layer with good test results was observed to contain Co, α-Fe, and Fe7Ni3 intermetallic compounds. The microstructure is transformed from fine grains at the top to columnar dendrites at the bottom.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140254161","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}
Christian Geiger, Sophie Grabmann, T. Weiss, Alena Gruendl, M. F. Zaeh
Hydrogen-powered polymer electrolyte membrane fuel cells (PEMFCs) show promising potential to power a wide range of mobile and stationary applications and to reduce greenhouse gas emissions significantly. In PEMFCs, the oxygen transport and the water transport are essential for a long lifetime and high-performance characteristics. The diffusion media (DM), located between the bipolar plate and the catalyst-coated membrane, is a crucial component of the fuel cell that significantly affects the cell-internal processes. Usually, the DM is a two-layer material system consisting of a microporous layer based on carbon black particles coated onto a porous gas diffusion layer (e.g., carbon paper). The properties of the microporous layer regarding the water transport at high current densities and, consequently, the fuel cell’s performance and lifetime can be improved by laser structuring. Within this work, different microporous layers with varying binder content and porosities were structured by locally ablating the material using ultrashort-pulsed laser radiation in the infrared wavelength range. The effect of varying process parameters was additionally investigated. Furthermore, the ablation efficiencies were calculated for increasing pulse repetition rates to qualify a process window for an industrial structuring process. The size of the micro-drillings and the heat-affected zone surrounding the hole were evaluated through topographic and microstructure analyses using a laser scanning microscope and a scanning electron microscope with energy-dispersive x-ray spectroscopy. The results showed a rather small influence of the porosity and composition of the microporous layer on the ablation behavior. In contrast, the laser structuring parameters influenced the micro-drilling geometry significantly.
氢动力聚合物电解质膜燃料电池（PEMFCs）在为各种移动和固定应用提供动力以及大幅减少温室气体排放方面显示出巨大的潜力。在 PEMFC 中，氧传输和水传输对于长寿命和高性能特性至关重要。扩散介质（DM）位于双极板和催化剂涂层膜之间，是燃料电池的重要组成部分，对电池内部过程有重大影响。通常，DM 是一种双层材料系统，由涂覆在多孔气体扩散层（如碳纸）上的基于炭黑颗粒的微孔层组成。微孔层在高电流密度下的水传输特性，以及由此产生的燃料电池性能和寿命，可以通过激光构造得到改善。在这项工作中，通过使用红外波长范围内的超短脉冲激光辐射对材料进行局部烧蚀，形成了不同粘合剂含量和孔隙率的微孔层。此外，还研究了不同工艺参数的影响。此外，还计算了脉冲重复率增加时的烧蚀效率，以确定工业结构化工艺的工艺窗口。通过使用激光扫描显微镜和扫描电子显微镜以及能量色散 X 射线光谱仪进行形貌和微结构分析，对微钻孔的尺寸和孔周围的热影响区进行了评估。结果表明，微孔层的孔隙率和成分对烧蚀行为的影响很小。相比之下，激光结构参数对微钻孔几何形状的影响很大。
{"title":"Influence of the material properties and the process parameters on the ablation behavior for the laser structuring of the diffusion media for fuel cells","authors":"Christian Geiger, Sophie Grabmann, T. Weiss, Alena Gruendl, M. F. Zaeh","doi":"10.2351/7.0001284","DOIUrl":"https://doi.org/10.2351/7.0001284","url":null,"abstract":"Hydrogen-powered polymer electrolyte membrane fuel cells (PEMFCs) show promising potential to power a wide range of mobile and stationary applications and to reduce greenhouse gas emissions significantly. In PEMFCs, the oxygen transport and the water transport are essential for a long lifetime and high-performance characteristics. The diffusion media (DM), located between the bipolar plate and the catalyst-coated membrane, is a crucial component of the fuel cell that significantly affects the cell-internal processes. Usually, the DM is a two-layer material system consisting of a microporous layer based on carbon black particles coated onto a porous gas diffusion layer (e.g., carbon paper). The properties of the microporous layer regarding the water transport at high current densities and, consequently, the fuel cell’s performance and lifetime can be improved by laser structuring. Within this work, different microporous layers with varying binder content and porosities were structured by locally ablating the material using ultrashort-pulsed laser radiation in the infrared wavelength range. The effect of varying process parameters was additionally investigated. Furthermore, the ablation efficiencies were calculated for increasing pulse repetition rates to qualify a process window for an industrial structuring process. The size of the micro-drillings and the heat-affected zone surrounding the hole were evaluated through topographic and microstructure analyses using a laser scanning microscope and a scanning electron microscope with energy-dispersive x-ray spectroscopy. The results showed a rather small influence of the porosity and composition of the microporous layer on the ablation behavior. In contrast, the laser structuring parameters influenced the micro-drilling geometry significantly.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140264943","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}
Hang Yuan, Jianing Hao, Chengyu Zhu, Ziqiang Dan, Luoxian Zhou, Jincheng Niu, Shenghao Kang, Jiajie Miao, Songlin Zhang
In this paper, we theoretically simulate the dynamic evolution of plasma from the interaction between a nanosecond pulsed laser and aluminum targets. The self-luminous image of the plasma plume during the laser loading process was experimentally obtained using high-speed photography. Theoretical and experimental results demonstrated that the plasma shielding effect and plasma lateral expansion have a significant effect on the plasma plume. It will affect laser–target coupling and further affect the evolution of plasma plumes. The detonation wave contained in the early stage of the laser-induced plasma plume directly affects the subsequent shock wave.
{"title":"Development of laser-ablated aluminum plasma plume during the irradiation of laser pulse","authors":"Hang Yuan, Jianing Hao, Chengyu Zhu, Ziqiang Dan, Luoxian Zhou, Jincheng Niu, Shenghao Kang, Jiajie Miao, Songlin Zhang","doi":"10.2351/7.0001292","DOIUrl":"https://doi.org/10.2351/7.0001292","url":null,"abstract":"In this paper, we theoretically simulate the dynamic evolution of plasma from the interaction between a nanosecond pulsed laser and aluminum targets. The self-luminous image of the plasma plume during the laser loading process was experimentally obtained using high-speed photography. Theoretical and experimental results demonstrated that the plasma shielding effect and plasma lateral expansion have a significant effect on the plasma plume. It will affect laser–target coupling and further affect the evolution of plasma plumes. The detonation wave contained in the early stage of the laser-induced plasma plume directly affects the subsequent shock wave.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139966935","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}
Andor Körmöczi, G. Horváth, Tamás Szörényi, Z. Geretovszky
The growing prominence of the electric vehicle industry, fueled by environmental concerns, has demanded innovation in various aspects of battery technologies with special emphasis on increasing the efficiency of both electric storage and its retrieval. An unexplored area of this is to identify the possibilities and limits of laser soldering. Here, we reveal the effects of surface pretreatment conditions and the amount of filler, along with the laser power and irradiation time on the characteristics of laser-soldered joints, by simultaneously evaluating the electrical and mechanical behavior of laser-soldered nickel-plated steel sheets (Hilumin®). By describing the morphological characteristics of the resolidified solder and the electrical and mechanical properties of the joints, we identify three, characteristically different morphological appearances and highlight the optimal one, where uniform and mostly void-free solder can be produced. Furthermore, we report a correlation between the threshold of upper sheet melting (either expressed as laser power or irradiation time) and joint deterioration in terms of the electrical and mechanical properties of the joint. We conclude that laser soldering can create joints with outstanding electrical conductance and adequate mechanical stability that meets the critical specifications of battery joining technologies when the surface pretreatment condition and processing parameters are properly optimized.
{"title":"Laser soldering of nickel plated steel sheets","authors":"Andor Körmöczi, G. Horváth, Tamás Szörényi, Z. Geretovszky","doi":"10.2351/7.0001244","DOIUrl":"https://doi.org/10.2351/7.0001244","url":null,"abstract":"The growing prominence of the electric vehicle industry, fueled by environmental concerns, has demanded innovation in various aspects of battery technologies with special emphasis on increasing the efficiency of both electric storage and its retrieval. An unexplored area of this is to identify the possibilities and limits of laser soldering. Here, we reveal the effects of surface pretreatment conditions and the amount of filler, along with the laser power and irradiation time on the characteristics of laser-soldered joints, by simultaneously evaluating the electrical and mechanical behavior of laser-soldered nickel-plated steel sheets (Hilumin®). By describing the morphological characteristics of the resolidified solder and the electrical and mechanical properties of the joints, we identify three, characteristically different morphological appearances and highlight the optimal one, where uniform and mostly void-free solder can be produced. Furthermore, we report a correlation between the threshold of upper sheet melting (either expressed as laser power or irradiation time) and joint deterioration in terms of the electrical and mechanical properties of the joint. We conclude that laser soldering can create joints with outstanding electrical conductance and adequate mechanical stability that meets the critical specifications of battery joining technologies when the surface pretreatment condition and processing parameters are properly optimized.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139966565","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 study aims to explore the impact of structural parameters on the formability, mechanical properties, and heat conductivity of body centered cubic (BCC) lattice structures produced through laser powder bed fusion (LPBF). The BCC lattice structures with varied cell diameters and cell sizes were fabricated using LPBF. Surface morphologies, compression properties, and numerical simulation of heat transfer were carried out. Results indicated that the relative density of the BCC structure was influenced by the diameter and size of the cell. An increase in the diameter or a decrease in the size of the cell led to an increase in the relative density of the BCC lattice structure. However, the surface forming quality decreased. On the other hand, the compressive strength of the structure increased, and the heat transfer property was also enhanced. The BCC lattice structure achieved its highest relative density and obtained a peak compressive strength of 320.66 MPa when the cell rod diameter was 1.5 mm and the cell size was 3 mm.
{"title":"Effects of structure parameters on performances of laser powder bed fusion processed AlSi10Mg body-centered cubic lattices","authors":"Meng Guo, Yule Yang, Chao Yang, Donghua Dai","doi":"10.2351/7.0001291","DOIUrl":"https://doi.org/10.2351/7.0001291","url":null,"abstract":"The study aims to explore the impact of structural parameters on the formability, mechanical properties, and heat conductivity of body centered cubic (BCC) lattice structures produced through laser powder bed fusion (LPBF). The BCC lattice structures with varied cell diameters and cell sizes were fabricated using LPBF. Surface morphologies, compression properties, and numerical simulation of heat transfer were carried out. Results indicated that the relative density of the BCC structure was influenced by the diameter and size of the cell. An increase in the diameter or a decrease in the size of the cell led to an increase in the relative density of the BCC lattice structure. However, the surface forming quality decreased. On the other hand, the compressive strength of the structure increased, and the heat transfer property was also enhanced. The BCC lattice structure achieved its highest relative density and obtained a peak compressive strength of 320.66 MPa when the cell rod diameter was 1.5 mm and the cell size was 3 mm.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140465850","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}
Omnia A. Abd El-Ghaffar, Nada O. Mohamed, M. El-Nagdy, Medhat W. Shafaa
This work aimed to apply a simple method to evaluate the effect of anticancer drugs’ treatment on in vitro models of cancer cells by laser biospeckle pattern measurements. Thus, the study is concerned with the detection of reduced dosage required for targeting tumors by drug combination encapsulated in liposomal nanoparticles using biospeckle measurements. The curcumin drug encapsulated in liposomal nanoparticles was applied to target the MCF-7 breast cancer cells and HepG2 liver cancer cells on slides as biospecimens with different concentrations for both cancer cell models, separately. For each cancer cell model under treatment, a simple way is to access this information, as the surfaces of biosample were illuminated by a coherent laser beam of green wavelengths of 532.0 nm with output power < 50 mW. The random interference effects were produced, which are known as biospeckle patterns. These speckle patterns were imaged for biosamples of the cancer cells under test treatment for each liposomal drug concentration, digitally. Then, laser biospeckle contrast measurements were used along with an image processing program to detect the change in speckle patterns due to the change in cancer cell size, cancer cell density, and bioavailability, which correlated to the various liposomal curcumin concentrations. First, the obtained results emphasized that the polydispersity index has an acceptable value lower than 0.7 for the effective clinical applications of the used nanocarrier liposome formulations presented in this study. Second, the study pointed to the laser biospeckle technique as a useful method to evaluate intensity and contrast measurements, which correspond to a safe use of the liposomal curcumin drug at a suitable concentration and an acceptable cytotoxicity.
{"title":"Laser biospeckle contrast measurements stimulated from liposomal nanocarriers incubated in vitro model cancer cells: A proven promising tool in clinical therapy","authors":"Omnia A. Abd El-Ghaffar, Nada O. Mohamed, M. El-Nagdy, Medhat W. Shafaa","doi":"10.2351/7.0001253","DOIUrl":"https://doi.org/10.2351/7.0001253","url":null,"abstract":"This work aimed to apply a simple method to evaluate the effect of anticancer drugs’ treatment on in vitro models of cancer cells by laser biospeckle pattern measurements. Thus, the study is concerned with the detection of reduced dosage required for targeting tumors by drug combination encapsulated in liposomal nanoparticles using biospeckle measurements. The curcumin drug encapsulated in liposomal nanoparticles was applied to target the MCF-7 breast cancer cells and HepG2 liver cancer cells on slides as biospecimens with different concentrations for both cancer cell models, separately. For each cancer cell model under treatment, a simple way is to access this information, as the surfaces of biosample were illuminated by a coherent laser beam of green wavelengths of 532.0 nm with output power < 50 mW. The random interference effects were produced, which are known as biospeckle patterns. These speckle patterns were imaged for biosamples of the cancer cells under test treatment for each liposomal drug concentration, digitally. Then, laser biospeckle contrast measurements were used along with an image processing program to detect the change in speckle patterns due to the change in cancer cell size, cancer cell density, and bioavailability, which correlated to the various liposomal curcumin concentrations. First, the obtained results emphasized that the polydispersity index has an acceptable value lower than 0.7 for the effective clinical applications of the used nanocarrier liposome formulations presented in this study. Second, the study pointed to the laser biospeckle technique as a useful method to evaluate intensity and contrast measurements, which correspond to a safe use of the liposomal curcumin drug at a suitable concentration and an acceptable cytotoxicity.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140463008","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. Selbmann, S. Gruber, Martin Propst, Tim Dorau, Robert Drexler, Filofteia-Laura Toma, Michael Mueller, L. Stepien, Elena Lopez, Christian Bach, F. Brueckner, Christoph Leyens
This contribution addresses the complete process chain of an annular aerospike breadboard engine fabricated by laser powder bed fusion using the nickel-based superalloy Inconel® 718. In order to qualify the material and process for this high-temperature application, an extensive material characterization campaign including density and roughness measurements, as well as tensile tests at room temperature, 700, and 900 °C, was conducted. In addition, various geometric features such as triangles, ellipses, and circular shapes were generated to determine the maximum unsupported overhang angle and geometrical accuracy. The results were taken into account in the design maturation of the manifold and the cooling channels of the aerospike breadboard engine. Postprocessing included heat treatment to increase mechanical properties, milling, turning, and eroding of interfaces to fulfill the geometrical tolerances, thermal barrier coating of thermally stressed surfaces for better protection of thermal loads, and laser welding of spike and shroud for the final assembly as well as quality assurance. This contribution goes beyond small density cubes and tensile samples and offers details on the iterations necessary for the successful printing of large complex shaped functional parts. The scientific question is how to verify the additive manufacturing process through tensile testing, simulation, and design iterations for complex geometries and reduce the number of failed prints.
这篇论文介绍了使用镍基超合金 Inconel® 718 通过激光粉末床熔融技术制造环形气刺面包板发动机的完整工艺链。为了使材料和工艺符合这一高温应用的要求，进行了广泛的材料表征活动，包括密度和粗糙度测量，以及室温、700 和 900 °C 下的拉伸试验。此外，还生成了各种几何特征，如三角形、椭圆形和圆形，以确定最大无支撑悬角和几何精度。在对航空航天面包板发动机的歧管和冷却通道进行成熟设计时考虑了这些结果。后处理包括热处理以提高机械性能，铣削、车削和侵蚀界面以满足几何公差要求，在热应力表面进行热障涂层以更好地保护热负荷，以及激光焊接尖头和护罩以进行最终组装和质量保证。这一贡献超越了小密度立方体和拉伸样品，提供了成功打印大型复杂形状功能部件所需的迭代细节。科学问题是如何通过拉伸测试、模拟和复杂几何形状的设计迭代来验证增材制造工艺，并减少打印失败的次数。
{"title":"Process qualification, additive manufacturing, and postprocessing of a hydrogen peroxide/kerosene 6 kN aerospike breadboard engine","authors":"A. Selbmann, S. Gruber, Martin Propst, Tim Dorau, Robert Drexler, Filofteia-Laura Toma, Michael Mueller, L. Stepien, Elena Lopez, Christian Bach, F. Brueckner, Christoph Leyens","doi":"10.2351/7.0001121","DOIUrl":"https://doi.org/10.2351/7.0001121","url":null,"abstract":"This contribution addresses the complete process chain of an annular aerospike breadboard engine fabricated by laser powder bed fusion using the nickel-based superalloy Inconel® 718. In order to qualify the material and process for this high-temperature application, an extensive material characterization campaign including density and roughness measurements, as well as tensile tests at room temperature, 700, and 900 °C, was conducted. In addition, various geometric features such as triangles, ellipses, and circular shapes were generated to determine the maximum unsupported overhang angle and geometrical accuracy. The results were taken into account in the design maturation of the manifold and the cooling channels of the aerospike breadboard engine. Postprocessing included heat treatment to increase mechanical properties, milling, turning, and eroding of interfaces to fulfill the geometrical tolerances, thermal barrier coating of thermally stressed surfaces for better protection of thermal loads, and laser welding of spike and shroud for the final assembly as well as quality assurance. This contribution goes beyond small density cubes and tensile samples and offers details on the iterations necessary for the successful printing of large complex shaped functional parts. The scientific question is how to verify the additive manufacturing process through tensile testing, simulation, and design iterations for complex geometries and reduce the number of failed prints.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139594541","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 present study focused on the environmentally friendly preparation, characterization, and certain biological activities of gold nanoparticles (Au-NPs) made with the Gundelia tournefortii (kenger) leaf extract. The results from devices such as transmission electron microscope, energy-dispersive x-ray spectrophotometer, and Fourier scanning electron microscope reveal the structures of nanoparticles. After an hour, the greatest surface plasmon resonance was discovered at 532.15 nm. The mean cubic crystallite size was calculated using the powder x-ray diffraction model and was found to be 23.53 nm. It was noted that the produced Au-NPs had spherical forms and hexagonal dimensions and ranged in size from 5 to 40 nm. The minimum inhibitory concentration and a colorimetric method for determining cell metabolic activity test, respectively, were used to investigate the suppressive effects of Au-NPs on the growth of pathogenic bacteria and healthy and cancer cell lines.
{"title":"Green synthesis, characterization of gold nanoparticles using Gundelia tournefortii leaf extract, and its cytotoxic activities","authors":"Zaid K. Alkaabi","doi":"10.2351/7.0001246","DOIUrl":"https://doi.org/10.2351/7.0001246","url":null,"abstract":"The present study focused on the environmentally friendly preparation, characterization, and certain biological activities of gold nanoparticles (Au-NPs) made with the Gundelia tournefortii (kenger) leaf extract. The results from devices such as transmission electron microscope, energy-dispersive x-ray spectrophotometer, and Fourier scanning electron microscope reveal the structures of nanoparticles. After an hour, the greatest surface plasmon resonance was discovered at 532.15 nm. The mean cubic crystallite size was calculated using the powder x-ray diffraction model and was found to be 23.53 nm. It was noted that the produced Au-NPs had spherical forms and hexagonal dimensions and ranged in size from 5 to 40 nm. The minimum inhibitory concentration and a colorimetric method for determining cell metabolic activity test, respectively, were used to investigate the suppressive effects of Au-NPs on the growth of pathogenic bacteria and healthy and cancer cell lines.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139596729","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}
Anne Tham, Kai Xin Siah, Ikhwan Mohd Noor, Ifwat Ghazali, Sin Tee Tan, Nizam Tamchek
Liquid-phase pulsed laser ablation (LP-PLA) is a physical deposition technique to fabricate micro- and nanoscale particles of polymer, glass, and ceramic materials. In this work, graphene oxide (GO) that was immersed in tetraethyl orthosilicate (TEOS) and ethanol was used to fabricate the graphene-silicone polymer using the LP-PLA technique. The GO-TEOS solution was ablated with different fluences of the laser. The ablated GO-TEOS solution was characterized by Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive x-ray, and ultraviolet-visible (UV-Vis) spectroscopy to study the graphene-silicone polymer properties. The FTIR result shows that the laser ablation has provided sufficient laser energy to create or break the chemical species of GO and TEOS compounds as observed on Si–O and C–O bonds. The Raman result shows the changes in the intensity in the D band, which suggests that the carbon atom of the GO has been functionalized with other compounds. Several large flakes were observed in the SEM images, representing the silicon polymer with the GO aggregation. The particle size in the range of 3–8 and 66–110 μm was formed due to the presence of uniformly sized nanoparticles of the GO-TEOS mixture and aggregation of the GO-TEOS nanoparticles into clusters. The zeta potential results indicated that the stability of the GO-TEOS mixture decreases after laser ablation. The UV-Vis result shows a broad absorption band with center at 492 and 532 nm with increasing absorbance at low fluence then saturated and decreased at maximum laser fluence. From the results above, several chemical interactions between GO and TEOS were observed, and the data suggested the laser fluence as the major source to cause both photothermal and photochemical reactions on the samples. In short, laser ablations provide sufficient energy to induce chemical bonding, which further allows structural modification of materials.
液相脉冲激光烧蚀（LP-PLA）是一种物理沉积技术，用于制造聚合物、玻璃和陶瓷材料的微米级和纳米级颗粒。在这项工作中，将氧化石墨烯（GO）浸入正硅酸四乙酯（TEOS）和乙醇中，利用 LP-PLA 技术制造石墨烯硅聚合物。用不同流量的激光对 GO-TEOS 溶液进行烧蚀。通过傅立叶变换红外光谱（FTIR）、拉曼光谱、扫描电子显微镜（SEM）、能量色散 X 射线和紫外可见光谱（UV-Vis）对烧蚀后的 GO-TEOS 溶液进行表征，以研究石墨烯-硅聚合物的特性。傅立叶变换红外光谱（FTIR）结果表明，激光烧蚀提供了足够的激光能量来产生或破坏石墨烯和 TEOS 化合物的化学物种，这在 Si-O 和 C-O 键上可以观察到。拉曼结果显示，D 波段的强度发生了变化，这表明 GO 的碳原子已被其他化合物功能化。在扫描电子显微镜图像中观察到几个大的薄片，这代表了硅聚合物与 GO 的聚集。由于 GO-TEOS 混合物中存在大小均匀的纳米颗粒，以及 GO-TEOS 纳米颗粒聚集成团，形成了粒径范围为 3-8 和 66-110 μm 的颗粒。zeta 电位结果表明，激光烧蚀后 GO-TEOS 混合物的稳定性降低。紫外-可见光谱结果显示，以 492 纳米和 532 纳米为中心的吸收带很宽，在低通量时吸光度增加，然后达到饱和，在最大激光通量时吸光度降低。从上述结果可以看出，GO 和 TEOS 之间发生了多种化学作用，这些数据表明激光通量是导致样品发生光热和光化学反应的主要来源。简而言之，激光烧蚀可提供足够的能量来诱导化学键，从而进一步改变材料的结构。
{"title":"Fabrication and structural modification of graphene oxide-tetraethyl orthosilicate solution via liquid-phase pulsed laser ablation","authors":"Anne Tham, Kai Xin Siah, Ikhwan Mohd Noor, Ifwat Ghazali, Sin Tee Tan, Nizam Tamchek","doi":"10.2351/7.0001227","DOIUrl":"https://doi.org/10.2351/7.0001227","url":null,"abstract":"Liquid-phase pulsed laser ablation (LP-PLA) is a physical deposition technique to fabricate micro- and nanoscale particles of polymer, glass, and ceramic materials. In this work, graphene oxide (GO) that was immersed in tetraethyl orthosilicate (TEOS) and ethanol was used to fabricate the graphene-silicone polymer using the LP-PLA technique. The GO-TEOS solution was ablated with different fluences of the laser. The ablated GO-TEOS solution was characterized by Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive x-ray, and ultraviolet-visible (UV-Vis) spectroscopy to study the graphene-silicone polymer properties. The FTIR result shows that the laser ablation has provided sufficient laser energy to create or break the chemical species of GO and TEOS compounds as observed on Si–O and C–O bonds. The Raman result shows the changes in the intensity in the D band, which suggests that the carbon atom of the GO has been functionalized with other compounds. Several large flakes were observed in the SEM images, representing the silicon polymer with the GO aggregation. The particle size in the range of 3–8 and 66–110 μm was formed due to the presence of uniformly sized nanoparticles of the GO-TEOS mixture and aggregation of the GO-TEOS nanoparticles into clusters. The zeta potential results indicated that the stability of the GO-TEOS mixture decreases after laser ablation. The UV-Vis result shows a broad absorption band with center at 492 and 532 nm with increasing absorbance at low fluence then saturated and decreased at maximum laser fluence. From the results above, several chemical interactions between GO and TEOS were observed, and the data suggested the laser fluence as the major source to cause both photothermal and photochemical reactions on the samples. In short, laser ablations provide sufficient energy to induce chemical bonding, which further allows structural modification of materials.","PeriodicalId":50168,"journal":{"name":"Journal of Laser Applications","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139607491","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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