Plume are common physical phenomena in fiber laser keyhole welding and have serious negative effects on the welding process. Based on this, this paper explores the regulation law of conventional shielding gas flow on plume. The results show that the shielding gas has a very significant effect on the suppression of the slender part of the plume, and the greater the gas flow rate, the better the plume removal effect. The addition of the shielding gas makes the welding process more stable, the molten pool flows stably, and the frequency of spatter eruption is reduced. Under the experimental conditions, the optimal shielding gas flow rate is around 15 l/min, and the penetration depth and width are increased by about 10% and decreased by about 22%, respectively, compared with that without adding the shielding gas. Based on the gas flow simulation, the gas flow pressure (about 132 Pa) generated by an appropriate amount of shielding gas (about 15 l/min) can press the liquid column and spatter near the keyhole mouth into the molten pool to avoid the spatter eruption. Excessive shielding gas flow will interfere with the flow of the molten pool excessively, and the weld surface will show a serious undercut phenomenon.
{"title":"Active control effect of shielding gas flow on high-power fiber laser welding plume","authors":"Jianglin Zou, Shun Xie, Hua Kong, Tao Liu, Chao Fang, Qiang Wu","doi":"10.2351/7.0001407","DOIUrl":"https://doi.org/10.2351/7.0001407","url":null,"abstract":"Plume are common physical phenomena in fiber laser keyhole welding and have serious negative effects on the welding process. Based on this, this paper explores the regulation law of conventional shielding gas flow on plume. The results show that the shielding gas has a very significant effect on the suppression of the slender part of the plume, and the greater the gas flow rate, the better the plume removal effect. The addition of the shielding gas makes the welding process more stable, the molten pool flows stably, and the frequency of spatter eruption is reduced. Under the experimental conditions, the optimal shielding gas flow rate is around 15 l/min, and the penetration depth and width are increased by about 10% and decreased by about 22%, respectively, compared with that without adding the shielding gas. Based on the gas flow simulation, the gas flow pressure (about 132 Pa) generated by an appropriate amount of shielding gas (about 15 l/min) can press the liquid column and spatter near the keyhole mouth into the molten pool to avoid the spatter eruption. Excessive shielding gas flow will interfere with the flow of the molten pool excessively, and the weld surface will show a serious undercut phenomenon.","PeriodicalId":508142,"journal":{"name":"Journal of Laser Applications","volume":"118 43","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141667642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Bunaziv, E. W. Hovig, O. E. Godinez Brizuela, Kai Zhang, Xiang Ma, X. Ren, M. Eriksson, P. Skjetne
Aluminum and its alloys are widely used in various applications including e-mobility applications due to their lightweight nature, high corrosion resistance, good electrical conductivity, and excellent processability such as extrusion and forming. However, aluminum and its alloys are difficult to process with a laser beam due to their high thermal conductivity and reflectivity. In this article, the two most used laser processes, i.e., laser welding and laser powder bed fusion (LPBF) additive manufacturing, for processing of aluminum have been studied. There are many common laser-material interaction mechanisms and challenges between the two processes. Deep keyhole mode is a preferred method for welding due to improved productivity, while a heat conduction mode is preferred in LPBF aiming for zero-defect parts. In LPBF, the processing maps are highly desirable to be constructed, which shows the transition zone. Presented numerical modeling provides a more in-depth understanding of porosity formation, and different laser beam movement paths have been tested including circular oscillation paths. High accuracy processing maps can be constructed for LPBF that allows us to minimize tedious and time-consuming experiments. As a result, a modeling framework is a highly viable option for the cost-efficient optimization of process parameters.
{"title":"CFD modeling for predicting imperfections in laser welding and additive manufacturing of aluminum alloys","authors":"I. Bunaziv, E. W. Hovig, O. E. Godinez Brizuela, Kai Zhang, Xiang Ma, X. Ren, M. Eriksson, P. Skjetne","doi":"10.2351/7.0001401","DOIUrl":"https://doi.org/10.2351/7.0001401","url":null,"abstract":"Aluminum and its alloys are widely used in various applications including e-mobility applications due to their lightweight nature, high corrosion resistance, good electrical conductivity, and excellent processability such as extrusion and forming. However, aluminum and its alloys are difficult to process with a laser beam due to their high thermal conductivity and reflectivity. In this article, the two most used laser processes, i.e., laser welding and laser powder bed fusion (LPBF) additive manufacturing, for processing of aluminum have been studied. There are many common laser-material interaction mechanisms and challenges between the two processes. Deep keyhole mode is a preferred method for welding due to improved productivity, while a heat conduction mode is preferred in LPBF aiming for zero-defect parts. In LPBF, the processing maps are highly desirable to be constructed, which shows the transition zone. Presented numerical modeling provides a more in-depth understanding of porosity formation, and different laser beam movement paths have been tested including circular oscillation paths. High accuracy processing maps can be constructed for LPBF that allows us to minimize tedious and time-consuming experiments. As a result, a modeling framework is a highly viable option for the cost-efficient optimization of process parameters.","PeriodicalId":508142,"journal":{"name":"Journal of Laser Applications","volume":"111 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141713339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Guanghui Zhang, Ze Lin, Xueqian Qin, Changlong Wei, Zhen Zhao, Yao Wang, Liao Zhou, Jia Zhou, Yuhong Long
In order to address the issue of thermal damage induced by laser processing of carbon fiber reinforced polymer (CFRP), researchers have conducted an optimization study of process parameters in the laser processing of CFRP. Their aim is to elucidate the relationship between process parameters and processing quality to minimize thermal damage. However, during laser processing, there exists a complex nonlinear relationship between process parameters and processing quality, making it challenging to establish high-precision predictive models, while the intrinsic connection between these two aspects remains incompletely revealed. In light of this, this study proposes utilization of machine learning techniques to explore the inherent relationship between process parameters and processing quality and establishes a 5-13-5 type back-propagation (BP) neural network predictive model. Subsequently, genetic algorithms are employed to optimize the weights and thresholds of the BP neural network, and the model is then subjected to validation. The results indicate that the BP neural network predictive model yields average errors of 5% for surface heat-affected zone (HAZ), 2.9% for groove width, 5.9% for cross-sectional HAZ, 1.8% for groove depth, and 4.5% for aspect ratio, demonstrating a relatively high level of accuracy but with notable fluctuations. The GA-BP model, when predicting the surface HAZ and the groove width, achieves errors of 4.5% and 2.7%, respectively, which are lower when compared to the BP model, indicating a higher predictive accuracy. The GA-BP model established in this study unveils the intrinsic connection between process parameters and processing quality, providing a novel means for an effective quality prediction in the processing of CFRP.
{"title":"High-accuracy predictive model for carbon fiber reinforced polymer laser machining quality using neural networks","authors":"Guanghui Zhang, Ze Lin, Xueqian Qin, Changlong Wei, Zhen Zhao, Yao Wang, Liao Zhou, Jia Zhou, Yuhong Long","doi":"10.2351/7.0001313","DOIUrl":"https://doi.org/10.2351/7.0001313","url":null,"abstract":"In order to address the issue of thermal damage induced by laser processing of carbon fiber reinforced polymer (CFRP), researchers have conducted an optimization study of process parameters in the laser processing of CFRP. Their aim is to elucidate the relationship between process parameters and processing quality to minimize thermal damage. However, during laser processing, there exists a complex nonlinear relationship between process parameters and processing quality, making it challenging to establish high-precision predictive models, while the intrinsic connection between these two aspects remains incompletely revealed. In light of this, this study proposes utilization of machine learning techniques to explore the inherent relationship between process parameters and processing quality and establishes a 5-13-5 type back-propagation (BP) neural network predictive model. Subsequently, genetic algorithms are employed to optimize the weights and thresholds of the BP neural network, and the model is then subjected to validation. The results indicate that the BP neural network predictive model yields average errors of 5% for surface heat-affected zone (HAZ), 2.9% for groove width, 5.9% for cross-sectional HAZ, 1.8% for groove depth, and 4.5% for aspect ratio, demonstrating a relatively high level of accuracy but with notable fluctuations. The GA-BP model, when predicting the surface HAZ and the groove width, achieves errors of 4.5% and 2.7%, respectively, which are lower when compared to the BP model, indicating a higher predictive accuracy. The GA-BP model established in this study unveils the intrinsic connection between process parameters and processing quality, providing a novel means for an effective quality prediction in the processing of CFRP.","PeriodicalId":508142,"journal":{"name":"Journal of Laser Applications","volume":"37 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141345933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Weihang Liu, Kaiyong Jiang, Masashi Kotobuki, Binggong Yan
Surface textured materials can exhibit enhanced properties due to their unique morphology, large surface area, and modified surface properties. The laser etching process has garnered significant attention for its capability to create textures on sample surfaces, resulting in a substantial improvement of surface properties. In this study, we investigate the application of femtosecond laser etching on solid electrolytes. To achieve this, an axicon lens is employed to transform the conventional Gaussian beam into a Bessel beam, with an extended focal depth that facilitates the laser etching process. A telescope laser system with a Bessel beam having a focal length of 2 mm is constructed based on finite element analysis. Glassy LAGP [Li1.5Al0.5Ge1.5(PO4)3] with a thickness of 2 mm is successfully etched simultaneously on both surfaces using this approach. Utilization of femtosecond laser pulses effectively prevents sample melting during the process. As predicted by finite element analysis, wider ditches are observed on the surface compared to those on the backside due to higher laser intensity at the surface region. By modifying the parameters of the telescope laser system, size and depth control can be achieved for these ditches.
{"title":"Femtosecond laser etching of Li1.5Al0.5Ge1.5(PO4)3 glass using the Bessel beam","authors":"Weihang Liu, Kaiyong Jiang, Masashi Kotobuki, Binggong Yan","doi":"10.2351/7.0001274","DOIUrl":"https://doi.org/10.2351/7.0001274","url":null,"abstract":"Surface textured materials can exhibit enhanced properties due to their unique morphology, large surface area, and modified surface properties. The laser etching process has garnered significant attention for its capability to create textures on sample surfaces, resulting in a substantial improvement of surface properties. In this study, we investigate the application of femtosecond laser etching on solid electrolytes. To achieve this, an axicon lens is employed to transform the conventional Gaussian beam into a Bessel beam, with an extended focal depth that facilitates the laser etching process. A telescope laser system with a Bessel beam having a focal length of 2 mm is constructed based on finite element analysis. Glassy LAGP [Li1.5Al0.5Ge1.5(PO4)3] with a thickness of 2 mm is successfully etched simultaneously on both surfaces using this approach. Utilization of femtosecond laser pulses effectively prevents sample melting during the process. As predicted by finite element analysis, wider ditches are observed on the surface compared to those on the backside due to higher laser intensity at the surface region. By modifying the parameters of the telescope laser system, size and depth control can be achieved for these ditches.","PeriodicalId":508142,"journal":{"name":"Journal of Laser Applications","volume":"30 16","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141346165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muhammad Siddiq, Zia Ur Rehman, Muhammad Asim Rasheed, Syed Mujtaba ul Hassan, H. Qayyum, Sultan Mehmood, Abdul Qayyum
In this study, a simple two step method is employed to sequentially synthesize bimetallic core/shell nanoparticles (NPs). In the first step, pure mono Au and Ag NPs are prepared via 1064 nm pulsed laser ablations in liquid. In the second step, the Au/Ag substrate immersed in the Au/Ag colloidal solution is exposed to the nanosecond laser at 1064 nm wavelength using various laser energies and ablation periods. The crystalline phase and morphology of the bimetallic core/shell NPs (Au/Ag, Ag/Au) are examined by x-ray diffraction and scanning electron microscopy, respectively. The results showed that highly crystalline, well-dispersed spherical monometallic and bimetallic core/shell NPs can be synthesized via pulse laser ablation in liquid. The average diameter of Au, Ag, Au/Ag, and Ag/Au NPs is 34, 40, 58, and 43 nm, respectively. With increasing laser energy, the plasmonic absorption peak of Au NPs redshifts and that of Ag NPs blueshifts. For core/shell, two plasmonic peaks were observed, each of which shifted with increasing ablation time for shell material. Organic dyes with concentrations of 10−5M of methylene-blue with NaBH4 of 0.05M and methylene-orange with NaBH4 of 0.1M are used to examine the catalytic performance of the NPs. The core/shell NPs performed better than monometallic NPs. In particular, the catalytic degradation efficiency of Au/Ag and Ag/Au NPs is approximately 90% in significantly less time than monometallic Au and Ag NPs.
{"title":"Synthesis of bimetallic core/shell nanoparticles via pulse laser ablation and their catalytic effectiveness in dye degradation","authors":"Muhammad Siddiq, Zia Ur Rehman, Muhammad Asim Rasheed, Syed Mujtaba ul Hassan, H. Qayyum, Sultan Mehmood, Abdul Qayyum","doi":"10.2351/7.0001347","DOIUrl":"https://doi.org/10.2351/7.0001347","url":null,"abstract":"In this study, a simple two step method is employed to sequentially synthesize bimetallic core/shell nanoparticles (NPs). In the first step, pure mono Au and Ag NPs are prepared via 1064 nm pulsed laser ablations in liquid. In the second step, the Au/Ag substrate immersed in the Au/Ag colloidal solution is exposed to the nanosecond laser at 1064 nm wavelength using various laser energies and ablation periods. The crystalline phase and morphology of the bimetallic core/shell NPs (Au/Ag, Ag/Au) are examined by x-ray diffraction and scanning electron microscopy, respectively. The results showed that highly crystalline, well-dispersed spherical monometallic and bimetallic core/shell NPs can be synthesized via pulse laser ablation in liquid. The average diameter of Au, Ag, Au/Ag, and Ag/Au NPs is 34, 40, 58, and 43 nm, respectively. With increasing laser energy, the plasmonic absorption peak of Au NPs redshifts and that of Ag NPs blueshifts. For core/shell, two plasmonic peaks were observed, each of which shifted with increasing ablation time for shell material. Organic dyes with concentrations of 10−5M of methylene-blue with NaBH4 of 0.05M and methylene-orange with NaBH4 of 0.1M are used to examine the catalytic performance of the NPs. The core/shell NPs performed better than monometallic NPs. In particular, the catalytic degradation efficiency of Au/Ag and Ag/Au NPs is approximately 90% in significantly less time than monometallic Au and Ag NPs.","PeriodicalId":508142,"journal":{"name":"Journal of Laser Applications","volume":"26 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141348984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Laser-arc hybrid additive manufacturing (LAHAM) based on the synergistic interaction of laser and arc has vast potential applications due to the advantages of high precision and fast manufacturing speed. Titanium alloy is a kind of indispensable material in the aerospace and marine industries because of its superior performance. This study primarily investigates the effect of laser power on formability, microstructure evolution, and mechanical properties of Ti-6Al-4V, a titanium alloy fabricated by LAHAM. The results indicate that the material utilization of the Ti-6Al-4V wire first increases and then decreases with the increasing laser power, reaching a maximum value of 95.48% at a power of 1500 W. As laser power increases, the acicular martensite α′ content in the LAHAM samples decreases, while the α phase increases and exhibits a coarsening phenomenon. Tensile strength increases with the rise in laser power, reaching a maximum horizontal tensile strength of 1080 MPa and a maximum vertical tensile strength of 1100 MPa. However, elongation decreases with increasing laser power. Microhardness decreases with the rise in laser power. The increase in laser power enhances the bonding between deposition layers, significantly improving the tensile strength of the specimens.
{"title":"Effects of laser power on microstructure and mechanical properties of titanium alloy fabricated by laser-arc hybrid additive manufacturing","authors":"Yuhang Chen, Juan Fu, Yong Zhao, Feiyun Wang, Fugang Chen, Guoqiang Chen, Yonghui Qin","doi":"10.2351/7.0001344","DOIUrl":"https://doi.org/10.2351/7.0001344","url":null,"abstract":"Laser-arc hybrid additive manufacturing (LAHAM) based on the synergistic interaction of laser and arc has vast potential applications due to the advantages of high precision and fast manufacturing speed. Titanium alloy is a kind of indispensable material in the aerospace and marine industries because of its superior performance. This study primarily investigates the effect of laser power on formability, microstructure evolution, and mechanical properties of Ti-6Al-4V, a titanium alloy fabricated by LAHAM. The results indicate that the material utilization of the Ti-6Al-4V wire first increases and then decreases with the increasing laser power, reaching a maximum value of 95.48% at a power of 1500 W. As laser power increases, the acicular martensite α′ content in the LAHAM samples decreases, while the α phase increases and exhibits a coarsening phenomenon. Tensile strength increases with the rise in laser power, reaching a maximum horizontal tensile strength of 1080 MPa and a maximum vertical tensile strength of 1100 MPa. However, elongation decreases with increasing laser power. Microhardness decreases with the rise in laser power. The increase in laser power enhances the bonding between deposition layers, significantly improving the tensile strength of the specimens.","PeriodicalId":508142,"journal":{"name":"Journal of Laser Applications","volume":"82 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141352796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiazhan Lu, Chonggui Li, Huaitao Xiong, Long Xia, Maoliang Li, Chengwei Hu
Simulation of the geometry and internal grain size changes of laser cladding has been extensively studied, with the majority of such simulations focusing on pure metal powders. However, there are fewer simulations for aluminum-based composite coatings by laser cladding. In this paper, a new three-dimensional model of laser cladding composite coatings is proposed, which can accurately determine the geometrical size of the AlSiTiNiCo-WC cladding layer and the internal grain morphology and grain size changes of the cladding layer. The temperature-selective judgment mechanism and material thermal property calculation ensure the calculation accuracy of the composite coating, while the model accurately and intuitively determines the state changes of the composite coating in the process of laser cladding. Furthermore, the model verifies the feasibility of the exponential decay laser source in the simulation of composite cladding, and temperature field analysis accurately predicts the trends of grain morphology and grain size inside the cladding. The simulation results show that the variation of the laser scanning speed has a more pronounced effect on the depth of the cladding layer. The high-temperature gradient at the top of the molten pool is more likely to form fine grains, and the bottom of the cladding layer tends to form coarse columnar crystals with the increase in the internal temperature gradient at the depth. The simulation results were compared with experimental results to validate the accuracy of the simulation process.
{"title":"Numerical simulation of thermal evolution and grain morphology of laser melted AlSiTiNiCo-WC composite coatings","authors":"Jiazhan Lu, Chonggui Li, Huaitao Xiong, Long Xia, Maoliang Li, Chengwei Hu","doi":"10.2351/7.0001278","DOIUrl":"https://doi.org/10.2351/7.0001278","url":null,"abstract":"Simulation of the geometry and internal grain size changes of laser cladding has been extensively studied, with the majority of such simulations focusing on pure metal powders. However, there are fewer simulations for aluminum-based composite coatings by laser cladding. In this paper, a new three-dimensional model of laser cladding composite coatings is proposed, which can accurately determine the geometrical size of the AlSiTiNiCo-WC cladding layer and the internal grain morphology and grain size changes of the cladding layer. The temperature-selective judgment mechanism and material thermal property calculation ensure the calculation accuracy of the composite coating, while the model accurately and intuitively determines the state changes of the composite coating in the process of laser cladding. Furthermore, the model verifies the feasibility of the exponential decay laser source in the simulation of composite cladding, and temperature field analysis accurately predicts the trends of grain morphology and grain size inside the cladding. The simulation results show that the variation of the laser scanning speed has a more pronounced effect on the depth of the cladding layer. The high-temperature gradient at the top of the molten pool is more likely to form fine grains, and the bottom of the cladding layer tends to form coarse columnar crystals with the increase in the internal temperature gradient at the depth. The simulation results were compared with experimental results to validate the accuracy of the simulation process.","PeriodicalId":508142,"journal":{"name":"Journal of Laser Applications","volume":" 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141373022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigated the temperature dependence of IN718 corrosion behavior in 3.5 wt. % NaCl solution, comparing conventionally rolled (Roll) and SLM-manufactured (SLM) samples. While both exhibited degradation with increasing temperature, the Roll sample presented a significantly higher susceptibility to corrosion by increasing the temperature from 25 to 70 °C. Rapid corrosion current density (icorr) of the Roll sample, which increased from 0.25 to 1.3 μA cm2, suggested the preferential γ-matrix dissolution and microgalvanic attack triggered by Laves phases and carbides acting as preferential dissolution sites. Conversely, the SLM sample showcased less segregation and fewer carbide phases due to its high cooling rate, resulting in a milder icorr rise (0.45–0.6 μA cm2). The findings hold promise for a more comprehensive understanding of IN718 performance and can guide the selection of optimal fabrication methods for components exposed to corrosive and high-temperature environments.
{"title":"Microstructure and corrosion of SLM IN718 in 3.5% NaCl solution at high temperatures","authors":"Mahdi Yeganeh, Sepehr Ghanavati, Amin Abdollahzadeh, Xiaolin Zhao","doi":"10.2351/7.0001379","DOIUrl":"https://doi.org/10.2351/7.0001379","url":null,"abstract":"This study investigated the temperature dependence of IN718 corrosion behavior in 3.5 wt. % NaCl solution, comparing conventionally rolled (Roll) and SLM-manufactured (SLM) samples. While both exhibited degradation with increasing temperature, the Roll sample presented a significantly higher susceptibility to corrosion by increasing the temperature from 25 to 70 °C. Rapid corrosion current density (icorr) of the Roll sample, which increased from 0.25 to 1.3 μA cm2, suggested the preferential γ-matrix dissolution and microgalvanic attack triggered by Laves phases and carbides acting as preferential dissolution sites. Conversely, the SLM sample showcased less segregation and fewer carbide phases due to its high cooling rate, resulting in a milder icorr rise (0.45–0.6 μA cm2). The findings hold promise for a more comprehensive understanding of IN718 performance and can guide the selection of optimal fabrication methods for components exposed to corrosive and high-temperature environments.","PeriodicalId":508142,"journal":{"name":"Journal of Laser Applications","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141377267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Limin Ma, Yuzhang Chen, Qiang Jia, Jing Han, Yishu Wang, Dan Li, Hongqiang Zhang, Guisheng Zou, Fu Guo
Silver nanoparticle (Ag NP) pastes become a potential die-attachment material with the increased electronic power density. However, the weakness of bonding interface between sintered Ag NPs and bare Cu substrate limits the applications of the Ag NPs paste, thereby reducing the shear strength of the sintered joint. In this work, ultrafast laser processing is utilized to enhance the bonding strength of the sintered Ag joint by fabricating a microstructure interface. The microstructure dimensions are tunable by controlling laser parameters, and then high-strength joints could be obtained. Different substrate microstructures were constructed, and the enhanced bonding mechanism was analyzed by characterizing the cross section and fracture surface morphologies of joints. The ultrafast laser processing could increase the surface energy of Cu substrates to form a more reliable connection with Ag NPs and more energy required for crack extension with the increasing connection area, thereby resulting in a significant improvement in the shear strength of the Ag NP joints. The patterned microstructures on the Cu substrate using this technique showed improved surface energy and increased number of connection areas on the substrate, showing potential for the use in third-generation semiconductors for highly reliable packaging.
随着电子功率密度的提高，银纳米粒子（Ag NP）浆料成为一种潜在的芯片连接材料。然而，烧结银纳米粒子与裸铜基板之间的结合界面较弱，这限制了银纳米粒子浆料的应用，从而降低了烧结连接的剪切强度。在这项工作中，利用超快激光加工技术，通过制造微结构界面来增强烧结银接合点的结合强度。通过控制激光参数，可以调整微结构尺寸，从而获得高强度接头。研究人员构建了不同的基底微结构，并通过分析接头的横截面和断裂面形态，分析了增强粘接的机理。超快激光加工可提高铜基材的表面能，使其与 Ag NPs 形成更可靠的连接，并且随着连接面积的增加，裂纹扩展所需的能量也增加，从而显著提高了 Ag NP 接头的剪切强度。使用该技术在铜基底上形成的图案化微结构显示出基底表面能的提高和连接区域数量的增加，显示出用于第三代半导体高可靠性封装的潜力。
{"title":"Construction of microstructures on the Cu substrate using ultrafast laser processing to enhance the bonding strength of sintered Ag nanoparticles","authors":"Limin Ma, Yuzhang Chen, Qiang Jia, Jing Han, Yishu Wang, Dan Li, Hongqiang Zhang, Guisheng Zou, Fu Guo","doi":"10.2351/7.0001327","DOIUrl":"https://doi.org/10.2351/7.0001327","url":null,"abstract":"Silver nanoparticle (Ag NP) pastes become a potential die-attachment material with the increased electronic power density. However, the weakness of bonding interface between sintered Ag NPs and bare Cu substrate limits the applications of the Ag NPs paste, thereby reducing the shear strength of the sintered joint. In this work, ultrafast laser processing is utilized to enhance the bonding strength of the sintered Ag joint by fabricating a microstructure interface. The microstructure dimensions are tunable by controlling laser parameters, and then high-strength joints could be obtained. Different substrate microstructures were constructed, and the enhanced bonding mechanism was analyzed by characterizing the cross section and fracture surface morphologies of joints. The ultrafast laser processing could increase the surface energy of Cu substrates to form a more reliable connection with Ag NPs and more energy required for crack extension with the increasing connection area, thereby resulting in a significant improvement in the shear strength of the Ag NP joints. The patterned microstructures on the Cu substrate using this technique showed improved surface energy and increased number of connection areas on the substrate, showing potential for the use in third-generation semiconductors for highly reliable packaging.","PeriodicalId":508142,"journal":{"name":"Journal of Laser Applications","volume":"29 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141383304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Shavelkina, M. M. Malikov, P. P. Ivanov, T. Borodina, G. E. Valyano
Pulsed laser ablation in liquids has become a simple, fast, and environmentally friendly method for the synthesis of carbon nanostructures since it does not require the use of toxic chemicals. The great advantage of this method is its ability to control the size, shape, and structure of the products by combining parameters of the laser, target material, and liquid. By ablation of two types of synthetic graphite with a high-power copper vapor laser in ethanol and distilled water, spherical graphene was obtained. The composition of the gas phase and the condensation temperature of carbon in the temperature range of 1000–5000 K were determined by means of thermodynamic modeling. The precursors for the formation of spherical graphene during laser ablation in alcohol and water are discussed.
在液体中进行脉冲激光烧蚀已成为一种简单、快速和环保的碳纳米结构合成方法，因为它不需要使用有毒化学物质。这种方法的最大优点是能够通过组合激光、目标材料和液体的参数来控制产物的大小、形状和结构。在乙醇和蒸馏水中用大功率铜蒸汽激光器烧蚀两种合成石墨，得到了球形石墨烯。通过热力学模型确定了 1000-5000 K 温度范围内的气相成分和碳的凝结温度。讨论了在酒精和水中进行激光烧蚀时形成球形石墨烯的前体。
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