Journal of Micro and Nano-Manufacturing最新文献_第4页

Precision Evaluation of Large Payload SCARA Robot for PCB Assembly 大载荷SCARA机器人PCB装配精度评价

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Journal of Micro and Nano-Manufacturing Pub Date : 2022-06-27 DOI: 10.1115/msec2022-85534

Andrew S. Nimon, A. Sherehiy, Moath H. A. Alqatamin, Danming Wei, D. Popa

引用次数: 0

Assessment of Shape Descriptors for Distortion Prediction in Powder Bed Fusion Process 粉末床熔合过程变形预测的形状描述符评估

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Journal of Micro and Nano-Manufacturing Pub Date : 2022-06-27 DOI: 10.1115/msec2022-86089

Hemnath Anandan Kumar, S. Kumaraguru

{"title":"Assessment of Shape Descriptors for Distortion Prediction in Powder Bed Fusion Process","authors":"Hemnath Anandan Kumar, S. Kumaraguru","doi":"10.1115/msec2022-86089","DOIUrl":"https://doi.org/10.1115/msec2022-86089","url":null,"abstract":"\u0000 Metal additive manufacturing paves the way for industries to create new applications through unique design capabilities. The powder bed fusion process is one among many metal additive manufacturing technologies that are commercially successful. Despite its numerous advantages and application in various fields, defects may occur during processing, which causes premature failure of components. Distortion is one of the major defects, and it depends on process settings, geometry, and orientation related. These distortions and dimensional deviations should be predicted faster for part qualification for many industrial applications. This work attempts to predict distortions based on shape descriptors to address this issue. Shape descriptors are definitions used to identify the details of the shape of a model to be printed. It can be either two dimensional or three dimensional. In this work, 2D shape descriptors are selected for analysis. These 2D shape descriptors can help identify how the design features significantly affect the part distortion in the PBF process. In this work, a few 2D shape descriptors are defined and modelled as a design feature to achieve the objective. Then the respective models are subjected to distortion analysis. The relationship between shape descriptors and distortion are studied through inherent strain method based simulation of distortion. It is observed from the results that most shape descriptors defined in this work can be used to predict the distortion. This work serves as a base and can help create knowledge for proposing design guidelines for the metal powder bed fusion process and helps in redesigning to prevent distortions.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":"281 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85594678","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}

引用次数: 0

A Functionally Gradient NiTi Shape-Memory Alloy Fabricated by Selective Laser Melting 选择性激光熔化制备功能梯度NiTi形状记忆合金

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Journal of Micro and Nano-Manufacturing Pub Date : 2022-06-27 DOI: 10.1115/msec2022-83645

Kun Li, J. Zhan, Ruijin Ma, Yingzhi Ren, Jinxin Lin

{"title":"A Functionally Gradient NiTi Shape-Memory Alloy Fabricated by Selective Laser Melting","authors":"Kun Li, J. Zhan, Ruijin Ma, Yingzhi Ren, Jinxin Lin","doi":"10.1115/msec2022-83645","DOIUrl":"https://doi.org/10.1115/msec2022-83645","url":null,"abstract":"\u0000 The near-equiatomic NiTi alloy has a shape memory function, but the simple forming structure limits its application. Selective laser melting is a promising way to manufacture functionally complex structures due to its layer-wise production advantage, which could broaden the applications of NiTi alloy in the engineering fields. This work explored a novel method of controlling the repetition of laser remelting to manufacture NiTi alloys with multiple phase-transformation temperatures via selective laser melting (SLM). The results demonstrates that the remelting strategy not only increases the ultimate tensile strength and elongation of the SLMed NiTi alloy, but also increases the Ms above room temperature. The increase in laser power increases the temperature at which martensite starts (Ms) to transformation in the range higher room temperature (25°C), thus increasing the critical stress of martensitic detwinning in the final sample. Through the optimized repetitive laser remelting strategy with different laser powers on specific areas of the sample, a functionally gradient NiTi build is successfully obtained. This study suggests SLM embedded with laser remelting is a potential method to realize 4D printing for NiTi alloys.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":"15 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84885035","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}

引用次数: 0

Support Vector Machines for Classification of Direct Energy Deposition Standoff Distance for Improved Process Control 基于直接能量沉积距离分类的支持向量机改进过程控制

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Journal of Micro and Nano-Manufacturing Pub Date : 2022-06-27 DOI: 10.1115/msec2022-85382

Zoe Alexander, Nathaniel DeVol, Molly Emig, K. Saleeby, T. Feldhausen, Thomas Kurfess, Katherine Fu, Christopher Saldaña

{"title":"Support Vector Machines for Classification of Direct Energy Deposition Standoff Distance for Improved Process Control","authors":"Zoe Alexander, Nathaniel DeVol, Molly Emig, K. Saleeby, T. Feldhausen, Thomas Kurfess, Katherine Fu, Christopher Saldaña","doi":"10.1115/msec2022-85382","DOIUrl":"https://doi.org/10.1115/msec2022-85382","url":null,"abstract":"\u0000 A critical factor in the implementation of direct energy deposition is the ability to maintain the standoff distance between the nozzle and the build surface, as this influences powder capture efficiency and overall part quality. Due to process-related variations, layer height may vary, causing unintended variation in standoff distance and poor build quality. While prior work has utilized contact probing to qualify standoff distance during processing, in situ methods for qualification of standoff distance are of major interest. The present work seeks to understand efficacy of image-based methods for classifying standoff distance variation in real-time using support vector machines (SVMs). It was hypothesized that the size of the melt pool and the amount of spatter will have significant correlations with deviations in the standoff distance; thus, SVMs were used on a dataset that is comprised of morphological features of melt pool size and image entropy. The SVM model was used to classify melt pool images into categories according to standoff distance variation from nominal. K-folds cross validation was used to find the optimal hyperparameters for the SVM model. To understand the impact of the selected features on the classification performance and inference speed, multiple models were trained with differing numbers of included features. Results for classification score, inference time, and image preprocessing/feature extraction from these data are reported. The present results show that the SVM model was able to predict the standoff distance classification with an accuracy of 97 percent and a speed of 0.122 s per image, making it a viable solution for real-time control of standoff distance.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":"45 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84894661","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}

引用次数: 0

Analytical Study of Shear-Thinning Fluid Flow in Direct Ink Writing Process 直墨书写过程中剪切-稀释流体流动的分析研究

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Journal of Micro and Nano-Manufacturing Pub Date : 2022-06-27 DOI: 10.1115/msec2022-85747

Zipeng Guo, F. Fei, Xuan Song, Chi Zhou

{"title":"Analytical Study of Shear-Thinning Fluid Flow in Direct Ink Writing Process","authors":"Zipeng Guo, F. Fei, Xuan Song, Chi Zhou","doi":"10.1115/msec2022-85747","DOIUrl":"https://doi.org/10.1115/msec2022-85747","url":null,"abstract":"\u0000 As a facile and versatile additive manufacturing technology, direct ink writing (DIW) has attracted considerable interest in academia and industry to fabricate three-dimensional structures with unique properties and functionalities. However, so far, the physical phenomena during the DIW process are not revealed in detail, leaving a research gap between the physical experiments and the underlying theories. Here, we presented a comprehensive simulation study of non-Newtonian ink flow during the DIW process. We used the computational fluid dynamics (CFD) method and revealed the shear-thinning behavior during the extrusion process. Different nozzle geometry models were adopted in the simulation. The advantages and drawbacks of each syringe-nozzle geometry were analyzed. In addition, the ink shear stress and velocity fields were investigated and compared in the case studies. Based on these investigations and analysis, we proposed an improved syringe-nozzle geometry towards high-resolution DIW. Consequently, the high-resolution and high shape fidelity DIW could enhance the DIW product performance. The results developed in this work offer valuable guidelines and could accelerate further advancement of DIW.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87494558","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}

引用次数: 1

A Comparative Study on the Effects of an Advanced Scan Pattern and Intelligent Scan Sequence on Thermal Distribution, Part Deformation, and Printing Time in PBF Additive Manufacturing 先进扫描模式和智能扫描顺序对PBF增材制造中热分布、零件变形和打印时间影响的比较研究

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Journal of Micro and Nano-Manufacturing Pub Date : 2022-06-27 DOI: 10.1115/msec2022-85301

Chuan He, Yueh-Lin Tsai, C. Okwudire

{"title":"A Comparative Study on the Effects of an Advanced Scan Pattern and Intelligent Scan Sequence on Thermal Distribution, Part Deformation, and Printing Time in PBF Additive Manufacturing","authors":"Chuan He, Yueh-Lin Tsai, C. Okwudire","doi":"10.1115/msec2022-85301","DOIUrl":"https://doi.org/10.1115/msec2022-85301","url":null,"abstract":"\u0000 Parts made using powder bed fusion (PBF) additive manufacturing often suffer from deformation, residual stresses, cracks, and other defects stemming from non-uniform thermal distribution during the printing process. Scan pattern (i.e., the geometric pattern of an infill) and scan sequence (i.e., the order in which features of a geometric pattern are scanned) are among the approaches that have been explored to achieve more uniform thermal distribution and reduce thermally-induced defects. The authors have recently proposed an intelligent approach (called SmartScan) for generating scan sequences. SmartScan is model-based and optimization-driven. However, it has only been applied to the most rudimentary scan patterns. This paper compares the separate and combined effects of an advanced scan pattern (the varying-helix pattern) and SmartScan on thermal distribution, part deformation, and printing time in PBF additive manufacturing. Simulations and experiments involving laser marking of AISI 316L stainless steel plates are employed for the comparison. Using SmartScan applied to a rudimentary pattern as a benchmark, the experimental results demonstrate that the application of the advanced pattern without SmartScan improved both temperature uniformity and reduced deformations by 20%, at the cost of 7% increase in printing time. The combination of the advanced pattern and SmartScan yielded 28% and 33% improvement in thermal uniformity and reduction in deformation, respectively, at the cost of 18% increase in scanning time.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":"23 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75825813","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}

引用次数: 0

Controlled Wetting of Spread Powder and its Impact on Line Formation in Binder Jetting 涂敷粉的可控润湿及其对粘结剂喷射成形的影响

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Journal of Micro and Nano-Manufacturing Pub Date : 2022-06-27 DOI: 10.1115/msec2022-85603

Colton Inkley, David G. Martin, Brennen Clark, N. Crane

{"title":"Controlled Wetting of Spread Powder and its Impact on Line Formation in Binder Jetting","authors":"Colton Inkley, David G. Martin, Brennen Clark, N. Crane","doi":"10.1115/msec2022-85603","DOIUrl":"https://doi.org/10.1115/msec2022-85603","url":null,"abstract":"\u0000 Binder Jetting (BJ) has increased in popularity and capability since its development at MIT as it offers advantages such as fast build rates, integrated overhang support, low-power requirements, and versatility in materials. However, defects arise during layer spreading and printing that are difficult to remove during post-processing. Many of these defects are caused by particle rearrangement/ejection during binder deposition. This study explores methods of reducing particle rearrangement and ejection by applying small amounts of moisture to increase the cohesive forces between powder particles. A moisture application system was built using a piezo-electric disk to atomize water to apply a desired liquid to the BJ powder bed without disruption. The moisture is applied after spreading a new layer. Lines of binder were printed using varying droplet spacings and moisture levels. Results show that the moisture delivery system applied moisture levels across the entire application area with a standard deviation under 23%. The moisture levels delivered also had a single position test-to-test uniformity standard deviation under 21%. All tested levels of moisture addition showed mitigation of the balling defects observed in lines printed using dry powder under the same parameters. Moisture addition decreased effective saturation and increased line dimensions (height and width), but lines printed using the smallest amount of moisture tested, showed similar saturation levels and line widths to lines printed in dry powder while still partially mitigating balling.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":"54 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80153534","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}

引用次数: 2

Mechanical Profile and 3D Printability of Cellular Structures 细胞结构的机械轮廓和3D打印能力

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Journal of Micro and Nano-Manufacturing Pub Date : 2022-06-27 DOI: 10.1115/msec2022-85541

Sina Rastegarzadeh, Samuel Muthusamy, Jida Huang

{"title":"Mechanical Profile and 3D Printability of Cellular Structures","authors":"Sina Rastegarzadeh, Samuel Muthusamy, Jida Huang","doi":"10.1115/msec2022-85541","DOIUrl":"https://doi.org/10.1115/msec2022-85541","url":null,"abstract":"\u0000 Microstructures are critical elements for mechanical metamaterials design and fabrication. Tailoring the internal microscale structural pattern can achieve a much broader range of bulk properties than the constituent materials, thus enabling the metamaterial design with extraordinary properties. Studying the mechanical properties and fabricability of microstructures is critical for understanding metamaterials’ structural design and macroscale performances. This paper categorizes the commonly designed microstructures into two main classes: deterministic implicit function-based and stochastic nature-based designing strategies. The mechanical properties and 3D printability of typical instances within the two classes are studied and experimentally analyzed. Specifically, we investigate the macroscale mechanical properties (e.g., Young’s modulus, shear modulus, bulk modulus, percentage of anisotropy) of microstructures defined with triply periodic minimal surfaces (TPMS), Fourier series-based functions (FSFs), Gaussian random filed-based (GRF), and Voronoi-based microstructures. Asymptotic homogenization is exploited herein to study the macroscale properties of different microstructures, and the manufacturability of the structures is experimentally analyzed and validated on an FDM printer. We summarize the mechanical profiles and manufacturability of these microstructures defined by various principles. The resulting mechanical profiles and manufacturability of microstructures provide a reasonable basis for establishing a microstructure database and shed light on the on-demand structural units generation for metamaterial design and fabrication.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":"16 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78739276","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}

引用次数: 0

Unexpectedly High Yields in Chemical Vapor Deposition of Carbon Nanotubes Based on Reactor Wall Thermochemical History 基于反应器壁热化学史的碳纳米管化学气相沉积的意外高产率

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Journal of Micro and Nano-Manufacturing Pub Date : 2022-06-27 DOI: 10.1115/msec2022-85633

G. Tomaraei, Moataz Abdulhafez, M. Bedewy

{"title":"Unexpectedly High Yields in Chemical Vapor Deposition of Carbon Nanotubes Based on Reactor Wall Thermochemical History","authors":"G. Tomaraei, Moataz Abdulhafez, M. Bedewy","doi":"10.1115/msec2022-85633","DOIUrl":"https://doi.org/10.1115/msec2022-85633","url":null,"abstract":"\u0000 While reactor wall preconditioning was previously shown to influence the growth of carbon nanotubes (CNTs) by chemical vapor deposition (CVD), it was previously only limited to studying the accumulating carbon deposits over the history of a large number of growth runs. However, the effect of leaving the reactor walls for an extended period of time between growth runs was not previously systematically studied. Here, we combine experimental measurements with a mathematical model to investigate the effect of thermochemical history of reactor walls on growth yield of vertically aligned CNT forests. Importantly, we demonstrate unexpectedly high CNT yield, exceeding one-order-of-magnitude taller forests, by increasing the interim period between runs (IPBR). We explain the results based on previously unexplored process sensitivity to trace amounts of oxygen-containing species in the reactor. In particular, uncontrolled amounts of water vapor desorbing from reactor walls during growth are modelled in this work. Our modeling results show the effect of IPBR on the outgassing dynamics revealing the underlying mechanism of generating growth promoting molecules during growth. By installing a new humidity sensor in our multizone rapid thermal CVD reactor, we are able to uniquely correlate the amount of moisture within the reactor to real-time measurements of growth kinetics, as well as ex situ characterization of CNT alignment and atomic defects. Our findings enable a scientifically grounded approach toward both boosting growth yield and improving its consistency by reducing run-to-run variations. Accordingly, engineered growth recipes can be envisioned to leverage this effect for improving manufacturing process scalability and robustness.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":"32 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91020899","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}

引用次数: 0

Effect of Withdrawal Velocity on Particle Entrainment From Density Mismatched Mixture 提取速度对密度不匹配混合物中颗粒夹带的影响

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Journal of Micro and Nano-Manufacturing Pub Date : 2022-06-27 DOI: 10.1115/msec2022-85745

S. Shovon, I. Khalil, Adeeb I. Alam, Bashir Khoda

{"title":"Effect of Withdrawal Velocity on Particle Entrainment From Density Mismatched Mixture","authors":"S. Shovon, I. Khalil, Adeeb I. Alam, Bashir Khoda","doi":"10.1115/msec2022-85745","DOIUrl":"https://doi.org/10.1115/msec2022-85745","url":null,"abstract":"\u0000 In this work, the physical phenomenon of the polydisperse micro-particle entrainment process from density mismatch mixture is investigated with the variation of substrate withdrawal speed. A liquid carrier system (LCS) is prepared by a polymer-based binder and an evaporating solvent. Nickel-based inorganic and spherical particles with a. moderate vol%. of 35% are added to the LCS solution. The cylindrical AISI 1006 mild steel wire substrate is dipped at different withdrawal speed ranging from 0.01 mms-1 to 20 mms-1. The binder vol%. is varied between 6.5% and 10.5%. Once the cylindrical substrate is extracted from the mixture, the surface coverage and the particle size are measured following the image analysis technique. The average particle size, coating thickness and the surface packing coverage by the particles are increasing with the higher withdrawal speed of the substrate. We observed relatively low size of particles (< 10 micrometers) as well as low surface coverage (∼33%) when the withdrawal speed remains at 0.01 mm/s. However, with high withdrawal speed (20 mm/s), we found all sizes of particles present on the substrate with a surface coverage of over 90%. The finding of this research will help to understand the high-volume solid transfer technique and develop a novel manufacturing process.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":"49 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91227179","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}

引用次数: 0