Obtaining fully dense products with high strength in one step at room temperature by powder metallurgy (PM) is generally not possible. However, doing so would reduce manufacturing and energy costs substantially. In this work, we have attempted to achieve this on commercially pure aluminum by utilizing the friction-assisted lateral extrusion process (FALEP) which has the capability of producing sheets from bulk or powder metal in a single step, by applying large shear strain. The texture, microstructure, and mechanical properties of the fully compacted powder sample were examined and compared to the bulk-sheet's properties obtained also by FALEP. The powder-FALEP sample showed a smaller grain size and significantly higher strength. Simulations carried out by the Taylor-type lattice-curvature-based polycrystal model shed light on the texture characteristics of the obtained materials and were in good agreement with the experiments.
{"title":"Room-temperature single-step production of ultrafine-grained bulk metallic sheets from Al powder","authors":"A. Pariyar, Viet Q Vu, S. Kailas, L. Toth","doi":"10.1115/1.4062582","DOIUrl":"https://doi.org/10.1115/1.4062582","url":null,"abstract":"\u0000 Obtaining fully dense products with high strength in one step at room temperature by powder metallurgy (PM) is generally not possible. However, doing so would reduce manufacturing and energy costs substantially. In this work, we have attempted to achieve this on commercially pure aluminum by utilizing the friction-assisted lateral extrusion process (FALEP) which has the capability of producing sheets from bulk or powder metal in a single step, by applying large shear strain. The texture, microstructure, and mechanical properties of the fully compacted powder sample were examined and compared to the bulk-sheet's properties obtained also by FALEP. The powder-FALEP sample showed a smaller grain size and significantly higher strength. Simulations carried out by the Taylor-type lattice-curvature-based polycrystal model shed light on the texture characteristics of the obtained materials and were in good agreement with the experiments.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46029933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Non-rigid compliant parts are widely used in industries today. One of the biggest challenges facing the industries is geometric variation management of these compliant parts, which directly impacts product quality and functionality. Existing rigid body based variation modeling is not suitable for compliant assembly while finite element analysis based methods have the disadvantage of requiring heavy computation efforts. In view of that, this paper develops a novel methodology to evaluate geometric variation propagation in multi-station compliant assembly based upon parametric space envelope (i.e. variation tool constructed from parametric curves). Three sources of variation: location-led positional variation, assembly deformation-induced variation and station transition caused variation are analyzed. Under proposal, geometric variations are modeled indirectly through a compact set of boundary control points. Compared with existing methods where geometric variation is modeled through targeting key feature points on the manufacturing part, the proposed approach brings modeling accuracy and computation efficiency. The effectiveness of the method is illustrated and verified through an industrial case study on a multi-station compliant panel assembly. The developed method provides industries a new way to manage geometric variation from compliant assembly.
{"title":"Modeling Variation in Multi-station Compliant Assembly using Parametric Space Envelope","authors":"C. Luo, Jiaqi Nie, P. Franciosa, D. Ceglarek","doi":"10.1115/1.4062579","DOIUrl":"https://doi.org/10.1115/1.4062579","url":null,"abstract":"\u0000 Non-rigid compliant parts are widely used in industries today. One of the biggest challenges facing the industries is geometric variation management of these compliant parts, which directly impacts product quality and functionality. Existing rigid body based variation modeling is not suitable for compliant assembly while finite element analysis based methods have the disadvantage of requiring heavy computation efforts. In view of that, this paper develops a novel methodology to evaluate geometric variation propagation in multi-station compliant assembly based upon parametric space envelope (i.e. variation tool constructed from parametric curves). Three sources of variation: location-led positional variation, assembly deformation-induced variation and station transition caused variation are analyzed. Under proposal, geometric variations are modeled indirectly through a compact set of boundary control points. Compared with existing methods where geometric variation is modeled through targeting key feature points on the manufacturing part, the proposed approach brings modeling accuracy and computation efficiency. The effectiveness of the method is illustrated and verified through an industrial case study on a multi-station compliant panel assembly. The developed method provides industries a new way to manage geometric variation from compliant assembly.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46391747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lattice structure metamaterials offer a variety of unique and tailorable properties, yet industrial adoption is slowed by manufacturability and inspection-related difficulties. Despite recent advances in laser powder bed fusion (LPBF) additive manufacturing (AM), the sub-millimeter features of lattices are at the edge of process capabilities and suffer from low geometric quality. To better understand their complex process-structure-property (PSP) relationships, octahedron structures were manufactured across a power spectrum, inspected, and mechanically tested. X-ray computed tomography (CT) was used to characterize lattice geometry, and demonstrated that lattice strut geometry measures, increased significantly as a function of laser power. Furthermore, lattices are shown to exhibit a direct correlation between laser power and mechanical performance metrics. Performance variations up to 60% are shown as a function of process parameters despite nominally identical geometry. Significant geometry variations are found to be the cause of performance variation, while material properties as measured by microindentation hardness are constant across the studied parameter range. PSP relationships are modeled, and the limitations of these models are explored. It was found that resulting models can predict mechanical performance based on geometric characteristics with R2 values of up to 0.86. Finally, mechanistic causes of observed performance changes are discussed.
{"title":"Process-Structure-Property Relationships of Laser Powder Bed Fusion Lattice Structures","authors":"E. Jost, J. Pegues, D. Moore, C. Saldana","doi":"10.1115/1.4062580","DOIUrl":"https://doi.org/10.1115/1.4062580","url":null,"abstract":"\u0000 Lattice structure metamaterials offer a variety of unique and tailorable properties, yet industrial adoption is slowed by manufacturability and inspection-related difficulties. Despite recent advances in laser powder bed fusion (LPBF) additive manufacturing (AM), the sub-millimeter features of lattices are at the edge of process capabilities and suffer from low geometric quality. To better understand their complex process-structure-property (PSP) relationships, octahedron structures were manufactured across a power spectrum, inspected, and mechanically tested. X-ray computed tomography (CT) was used to characterize lattice geometry, and demonstrated that lattice strut geometry measures, increased significantly as a function of laser power. Furthermore, lattices are shown to exhibit a direct correlation between laser power and mechanical performance metrics. Performance variations up to 60% are shown as a function of process parameters despite nominally identical geometry. Significant geometry variations are found to be the cause of performance variation, while material properties as measured by microindentation hardness are constant across the studied parameter range. PSP relationships are modeled, and the limitations of these models are explored. It was found that resulting models can predict mechanical performance based on geometric characteristics with R2 values of up to 0.86. Finally, mechanistic causes of observed performance changes are discussed.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46636559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Q. Bai, Pengcheng Li, W. Tian, Jianxin Shen, Bo Li, Junshan Hu
Compared with a single manipulator manufacturing cell, a dual manipulator cooperative system has more advantages in reconfigurability and flexibility. However, there are calibration errors and multi-source disturbances in the collaborative process, which lead to the processing trajectory accuracy defects of large-scale associated machining features. To solve the above problems, a practical path tracking synchronous control algorithm is proposed based on position based visual servoing (PBVS) in this paper for the dual manipulator cooperative system, the proposed dynamic cross-coupled sliding mode controller (DCSMC) scheme can realize dynamic paths correction while executing the pre-planned paths. Moreover, since the cross-coupled technology is integrated into the proposed control algorithm for dynamic path tracking based on the real-time feedback of the highly repeatable 3D visual measurement instrument (VMI), both the tracking and synchronous errors of the dual manipulators converge to zero. Finally, the stability of the proposed controller has been verified by the Lyapunov method. In the end, the real-time line and circle path tracking experimental results using two industrial manipulators demonstrate that the proposed scheme can achieve better synchronous tracking accuracy than the independent control scheme.
{"title":"Vision guided dynamic synchronous path tracking control of dual manipulator cooperative system","authors":"Q. Bai, Pengcheng Li, W. Tian, Jianxin Shen, Bo Li, Junshan Hu","doi":"10.1115/1.4062546","DOIUrl":"https://doi.org/10.1115/1.4062546","url":null,"abstract":"\u0000 Compared with a single manipulator manufacturing cell, a dual manipulator cooperative system has more advantages in reconfigurability and flexibility. However, there are calibration errors and multi-source disturbances in the collaborative process, which lead to the processing trajectory accuracy defects of large-scale associated machining features. To solve the above problems, a practical path tracking synchronous control algorithm is proposed based on position based visual servoing (PBVS) in this paper for the dual manipulator cooperative system, the proposed dynamic cross-coupled sliding mode controller (DCSMC) scheme can realize dynamic paths correction while executing the pre-planned paths. Moreover, since the cross-coupled technology is integrated into the proposed control algorithm for dynamic path tracking based on the real-time feedback of the highly repeatable 3D visual measurement instrument (VMI), both the tracking and synchronous errors of the dual manipulators converge to zero. Finally, the stability of the proposed controller has been verified by the Lyapunov method. In the end, the real-time line and circle path tracking experimental results using two industrial manipulators demonstrate that the proposed scheme can achieve better synchronous tracking accuracy than the independent control scheme.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48811358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Towards achieving control over the kerfing through abrasive waterjet submerged milling, there is a need to (i) understand the influence of the water column height on the kerf quality and (ii) develop a model for the prediction of the kerf characteristics. This study performs detailed experimentation to assess the kerf quality enhancement in submerged milling relative to the in-air on Al6061. From the modelling perspective, there are very limited efforts in developing a comprehensive model that includes both the jet flow dynamics and material removal models - this is the missing link. Towards this, a comprehensive model is proposed and validated for the prediction of kerf in in-air and submerged conditions by considering (i) jet dynamics and (ii) jet-material interaction. From the experimental results, it is observed that by adopting the submerged milling, the damaged region, top kerf width and edge radius got reduced by 20.3%, 13.53%, and 22.7%, respectively. However, this enhancement in the kerf quality is associated with a reduction in the centreline erosion depth (hmax) by 12.33% and a material removal rate by 24.52%. The material removal mechanism is more uniform and directed in the submerged milling, whereas in-air is random. The proposed model predicted the kerf cross-sectional profile in submerged milling and in-air with a mean absolute error of 60 μm and 57 μm, squared Pearson correlation coefficient of 0.97 and 0.99, and the hmax with a maximum error of 1.3% and 1.4%.
{"title":"Experimental investigation and modelling of the kerf profile in submerged milling by macro abrasive waterjet","authors":"R. Ravi, Deepu Kumar T. N., D. Srinivasu","doi":"10.1115/1.4062547","DOIUrl":"https://doi.org/10.1115/1.4062547","url":null,"abstract":"\u0000 Towards achieving control over the kerfing through abrasive waterjet submerged milling, there is a need to (i) understand the influence of the water column height on the kerf quality and (ii) develop a model for the prediction of the kerf characteristics. This study performs detailed experimentation to assess the kerf quality enhancement in submerged milling relative to the in-air on Al6061. From the modelling perspective, there are very limited efforts in developing a comprehensive model that includes both the jet flow dynamics and material removal models - this is the missing link. Towards this, a comprehensive model is proposed and validated for the prediction of kerf in in-air and submerged conditions by considering (i) jet dynamics and (ii) jet-material interaction. From the experimental results, it is observed that by adopting the submerged milling, the damaged region, top kerf width and edge radius got reduced by 20.3%, 13.53%, and 22.7%, respectively. However, this enhancement in the kerf quality is associated with a reduction in the centreline erosion depth (hmax) by 12.33% and a material removal rate by 24.52%. The material removal mechanism is more uniform and directed in the submerged milling, whereas in-air is random. The proposed model predicted the kerf cross-sectional profile in submerged milling and in-air with a mean absolute error of 60 μm and 57 μm, squared Pearson correlation coefficient of 0.97 and 0.99, and the hmax with a maximum error of 1.3% and 1.4%.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42810393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, a novel design scheme for a power skiving cutter and its grinding wheel profile is proposed based on the geometry of a target circular spline (CS) workpiece. First, a generalized mathematical model of a target CS tooth profile is expressed using a B-spline curve. Subsequently, the nominal cutting edge of the skiving cutter for generating an error-free CS is derived based on power-skiving kinematics. In addition, the axial profile of the grinding wheel for generating the derived nominal cutting edge is resolved based on lengthwise-reciprocating grinding kinematics. Numerical examples are presented to demonstrate the proposed design process for the skiving cutter and its grinding wheel. The profile accuracy of the CS yielded by the designed nominal cutting edge is computed to validate the proposed design processes. Moreover, errors of the skived CS profile resulting from various resharpening depths by grinding back the stepped rake face of the skiving cutter are investigated. Finally, to effectively extend the tool life of the skiving cutter, a compensation rolling angle is introduced into the CS skiving process.
{"title":"Design and Manufacture of Power Skiving Cutter from Target Circular Spline Geometry","authors":"Yun-Hao Cheng, Yi-Cheng Chen","doi":"10.1115/1.4062496","DOIUrl":"https://doi.org/10.1115/1.4062496","url":null,"abstract":"\u0000 In this study, a novel design scheme for a power skiving cutter and its grinding wheel profile is proposed based on the geometry of a target circular spline (CS) workpiece. First, a generalized mathematical model of a target CS tooth profile is expressed using a B-spline curve. Subsequently, the nominal cutting edge of the skiving cutter for generating an error-free CS is derived based on power-skiving kinematics. In addition, the axial profile of the grinding wheel for generating the derived nominal cutting edge is resolved based on lengthwise-reciprocating grinding kinematics. Numerical examples are presented to demonstrate the proposed design process for the skiving cutter and its grinding wheel. The profile accuracy of the CS yielded by the designed nominal cutting edge is computed to validate the proposed design processes. Moreover, errors of the skived CS profile resulting from various resharpening depths by grinding back the stepped rake face of the skiving cutter are investigated. Finally, to effectively extend the tool life of the skiving cutter, a compensation rolling angle is introduced into the CS skiving process.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46028409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Ambrosio, V. Wagner, G. Dessein, J. Vivas, O. Cahuc
Flow-related defects in friction stir welding are critical for the joints affecting their mechanical properties and functionality. One way to identify them, avoiding long and sometimes expensive destructive and non-destructive testing, is using machine learning tools with monitored physical quantities as input data. In this work, artificial neural network and decision tree models are trained, validated, and tested on a large dataset consisting of forces, torque, and temperature in the stirred zone measured when friction stir welding three aluminum alloys such as 5083-H111, 6082-T6, and 7075-T6. The built models successfully classified welds between sound and defective with accuracies over 95%, proving their usefulness in identifying defects on new datasets. Independently from the models, the temperature in the stirred zone is found to be the most influential parameter for the assessment of friction stir weld quality.
{"title":"Machine learning tools for flow-related defects detection in friction stir welding","authors":"D. Ambrosio, V. Wagner, G. Dessein, J. Vivas, O. Cahuc","doi":"10.1115/1.4062457","DOIUrl":"https://doi.org/10.1115/1.4062457","url":null,"abstract":"\u0000 Flow-related defects in friction stir welding are critical for the joints affecting their mechanical properties and functionality. One way to identify them, avoiding long and sometimes expensive destructive and non-destructive testing, is using machine learning tools with monitored physical quantities as input data. In this work, artificial neural network and decision tree models are trained, validated, and tested on a large dataset consisting of forces, torque, and temperature in the stirred zone measured when friction stir welding three aluminum alloys such as 5083-H111, 6082-T6, and 7075-T6. The built models successfully classified welds between sound and defective with accuracies over 95%, proving their usefulness in identifying defects on new datasets. Independently from the models, the temperature in the stirred zone is found to be the most influential parameter for the assessment of friction stir weld quality.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42089346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Human-robot collaboration (HRC) has been regarded as one of the most promising paradigms for human-centric smart manufacturing in the context of Industry 5.0. To improve human well-being and robotic flexibility in HRC, a plethora of works around human body perception have emerged over the years, but most of them only considered a specific facade of human recognition while lacking a holistic perspective of the human operator. To this end, this study proposes an exemplary vision-based Human Digital Twin (HDT) model for highly dynamic HRC applications. The model mainly consists of a convolutional neural network that can simultaneously model the hierarchical human status including 3D human posture, action intention, and ergonomic risk. Then, on the basis of the constructed HDT, a robotic motion planning strategy is further introduced with the aim of adaptively optimizing the robotic motion trajectory. Further experiments and case studies are conducted in an HRC scenario to demonstrate the effectiveness of our approach.
{"title":"A Vision-based Human Digital Twin Modelling Approach for Adaptive Human-Robot Collaboration","authors":"Junming Fan, Pai Zheng, Carman K. M. Lee","doi":"10.1115/1.4062430","DOIUrl":"https://doi.org/10.1115/1.4062430","url":null,"abstract":"\u0000 Human-robot collaboration (HRC) has been regarded as one of the most promising paradigms for human-centric smart manufacturing in the context of Industry 5.0. To improve human well-being and robotic flexibility in HRC, a plethora of works around human body perception have emerged over the years, but most of them only considered a specific facade of human recognition while lacking a holistic perspective of the human operator. To this end, this study proposes an exemplary vision-based Human Digital Twin (HDT) model for highly dynamic HRC applications. The model mainly consists of a convolutional neural network that can simultaneously model the hierarchical human status including 3D human posture, action intention, and ergonomic risk. Then, on the basis of the constructed HDT, a robotic motion planning strategy is further introduced with the aim of adaptively optimizing the robotic motion trajectory. Further experiments and case studies are conducted in an HRC scenario to demonstrate the effectiveness of our approach.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45745663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pee-Yew Lee, C. Weng, H. Huang, Li-Yan Wu, Guo-Hao Lu, Chao-Feng Liu, Cheng-You Chen, Ting-Yu Li, Yung-Sheng Lin
Micro/nano-textured Si wafers manufactured using metal-assisted chemical etching (MACE) have been the focus of several studies, but the mechanism of bubble generation during the MACE process affecting textured surfaces has rarely been reported. This study investigated the bubble effect due to the different placement patterns of the Si wafer (face-up, stirred face-down, and face-down). The results indicated that the placement pattern of the Si wafer notably influences the uniformity of outward appearance. However, no significant differences were noted in the scanning electron microscopy images of Si nanowires (SiNWs) at 0.5 h of etching. At 2 h of etching, the outward appearance uniformity of face-up etching was more homogeneous than that of stirred face-down and face-down patterns, and the SiNWs processed through face-up etching were longer (41 μm) than those subjected to stirred face-down etching (36 μm) and face-down etching (32 μm). Therefore, the placement pattern of Si wafer can affect the uniformity and properties of SiNWs because of bubbles trapped inside cavities or between SiNWs.
{"title":"Bubble Effects on Manufacturing of Silicon Nanowires by Metal-Assisted Chemical Etching","authors":"Pee-Yew Lee, C. Weng, H. Huang, Li-Yan Wu, Guo-Hao Lu, Chao-Feng Liu, Cheng-You Chen, Ting-Yu Li, Yung-Sheng Lin","doi":"10.1115/1.4062392","DOIUrl":"https://doi.org/10.1115/1.4062392","url":null,"abstract":"\u0000 Micro/nano-textured Si wafers manufactured using metal-assisted chemical etching (MACE) have been the focus of several studies, but the mechanism of bubble generation during the MACE process affecting textured surfaces has rarely been reported. This study investigated the bubble effect due to the different placement patterns of the Si wafer (face-up, stirred face-down, and face-down). The results indicated that the placement pattern of the Si wafer notably influences the uniformity of outward appearance. However, no significant differences were noted in the scanning electron microscopy images of Si nanowires (SiNWs) at 0.5 h of etching. At 2 h of etching, the outward appearance uniformity of face-up etching was more homogeneous than that of stirred face-down and face-down patterns, and the SiNWs processed through face-up etching were longer (41 μm) than those subjected to stirred face-down etching (36 μm) and face-down etching (32 μm). Therefore, the placement pattern of Si wafer can affect the uniformity and properties of SiNWs because of bubbles trapped inside cavities or between SiNWs.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41477361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Semih Akin, Puyuan Wu, Chandra Nath, Jun Chen, M. Jun
Supersonic cold spraying of liquid droplets containing functional nanomaterials is of particular interest in advanced thin-film coating, that enabling high-adhesion strength particle deposition. In cold spraying, the optimum design of the supersonic nozzle is essential for accelerating particles to desired velocities. However, research on the supersonic nozzle design for liquid droplets is limited. Thus, we thoroughly investigate the influence of nozzle geometrical parameters (i.e., throat diameter, exit diameter, divergent length) on droplets acceleration by numerical modeling followed by experimental validation, and a case study on surface coating application. Two-phase flow modeling was used to predict droplets' behavior in continuous gas flow for different nozzle configurations. The results show that the nozzle expansion ratio - a function of throat and exit diameters - has a significant influence on droplet velocity, followed by divergent length. In particular, to correctly accelerate “low-inertia liquid droplets”, optimum nozzle expansion ratio for an axisymmetric convergent-divergent nozzle is found to be in a range of 1.5-2.5 for different sets of parameters, which is different than the recommended expansion ratio (i.e., 5-9) for cold spraying of conventional “metal” particles. Based on the simulation results, an optimal design of supersonic nozzle is selected and prototyped for the experimental studies. Numerical modeling results are validated by particle image velocimetry (PIV) measurements. Moreover, coating experiments confirm the adaptability of the optimized nozzle for supersonic cold spraying of droplets containing nanoparticles, which thereby has the potential for rapid production of advanced thin films.
{"title":"A study on converging-diverging nozzle design for supersonic spraying of liquid droplets toward nanocoating applications","authors":"Semih Akin, Puyuan Wu, Chandra Nath, Jun Chen, M. Jun","doi":"10.1115/1.4062351","DOIUrl":"https://doi.org/10.1115/1.4062351","url":null,"abstract":"\u0000 Supersonic cold spraying of liquid droplets containing functional nanomaterials is of particular interest in advanced thin-film coating, that enabling high-adhesion strength particle deposition. In cold spraying, the optimum design of the supersonic nozzle is essential for accelerating particles to desired velocities. However, research on the supersonic nozzle design for liquid droplets is limited. Thus, we thoroughly investigate the influence of nozzle geometrical parameters (i.e., throat diameter, exit diameter, divergent length) on droplets acceleration by numerical modeling followed by experimental validation, and a case study on surface coating application. Two-phase flow modeling was used to predict droplets' behavior in continuous gas flow for different nozzle configurations. The results show that the nozzle expansion ratio - a function of throat and exit diameters - has a significant influence on droplet velocity, followed by divergent length. In particular, to correctly accelerate “low-inertia liquid droplets”, optimum nozzle expansion ratio for an axisymmetric convergent-divergent nozzle is found to be in a range of 1.5-2.5 for different sets of parameters, which is different than the recommended expansion ratio (i.e., 5-9) for cold spraying of conventional “metal” particles. Based on the simulation results, an optimal design of supersonic nozzle is selected and prototyped for the experimental studies. Numerical modeling results are validated by particle image velocimetry (PIV) measurements. Moreover, coating experiments confirm the adaptability of the optimized nozzle for supersonic cold spraying of droplets containing nanoparticles, which thereby has the potential for rapid production of advanced thin films.","PeriodicalId":16299,"journal":{"name":"Journal of Manufacturing Science and Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45353497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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