Olalekan O. Olowo, Ruoshi Zhang, A. Sherehiy, B. Goulet, Alexander Curry, Danming Wei, Zhong Yang, Moath H. A. Alqatamin, D. Popa
Enhancing physical human-robot interaction requires the improvement in the tactile perception of physical touch. Robot skin sensors exhibiting piezoresistive behavior can be used in conjunction with collaborative robots. In past work, fabrication of these tactile arrays was done using cleanroom techniques such as spin coating, photolithography, sputtering, wet and dry etching onto flexible polymers. In this paper, we present an addictive, non-cleanroom improved process of depositing PEDOT: PSS, which is the organic polymer responsible for the piezoresistive phenomenon of the robot skin sensor arrays. This publication details the patterning of the robot skin sensor structures and the adaptation of the inkjet printing technology to the fabrication process. This increases the possibility of scaling the production output while reducing the cleanroom fabrication cost and time from an approximately five-hour PEDOT: PSS deposition process to five minutes. Furthermore, the testing of these skin sensor arrays is carried out on a testing station equipped with a force plunger and an integrated circuit designed to provide perception feedback on various force load profiles controlled in an automated process. The results show uniform deposition of the PEDOT: PSS, consistent resistance measurement, and appropriate tactile response across an array of 16 sensors.
{"title":"Inkjet Printing of PEDOT:PSS Inks for Robotic Skin Sensors","authors":"Olalekan O. Olowo, Ruoshi Zhang, A. Sherehiy, B. Goulet, Alexander Curry, Danming Wei, Zhong Yang, Moath H. A. Alqatamin, D. Popa","doi":"10.1115/msec2022-80989","DOIUrl":"https://doi.org/10.1115/msec2022-80989","url":null,"abstract":"\u0000 Enhancing physical human-robot interaction requires the improvement in the tactile perception of physical touch. Robot skin sensors exhibiting piezoresistive behavior can be used in conjunction with collaborative robots. In past work, fabrication of these tactile arrays was done using cleanroom techniques such as spin coating, photolithography, sputtering, wet and dry etching onto flexible polymers. In this paper, we present an addictive, non-cleanroom improved process of depositing PEDOT: PSS, which is the organic polymer responsible for the piezoresistive phenomenon of the robot skin sensor arrays. This publication details the patterning of the robot skin sensor structures and the adaptation of the inkjet printing technology to the fabrication process. This increases the possibility of scaling the production output while reducing the cleanroom fabrication cost and time from an approximately five-hour PEDOT: PSS deposition process to five minutes. Furthermore, the testing of these skin sensor arrays is carried out on a testing station equipped with a force plunger and an integrated circuit designed to provide perception feedback on various force load profiles controlled in an automated process. The results show uniform deposition of the PEDOT: PSS, consistent resistance measurement, and appropriate tactile response across an array of 16 sensors.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":"7 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90834437","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}
Andrew S. Nimon, A. Sherehiy, Moath H. A. Alqatamin, Danming Wei, D. Popa
The placement of SMD components is usually performed with Cartesian type robots, a task known as pick-and-place (P&P). Small Selective Compliance Articulated Robot Arm (SCARA) robots are also growing in popularity for this use because of their quick and accurate performance. This paper describes the use of the Lean Robotic Micromanufacturing (LRM) framework applied on a large, 10kg payload, industrial SCARA robot for PCB assembly. The LRM framework guided the precision evaluation of the PCB assembly process and provided a prediction of the placement precision and yield. We experimentally evaluated the repeatability of the system, as well as the resulting collective errors during the assembly. Results confirm that the P&P task can achieve the required assembly tolerance of 200 microns without employing closed-loop visual servoing, therefore considerably decreasing the system complexity and assembly time.
{"title":"Precision Evaluation of Large Payload SCARA Robot for PCB Assembly","authors":"Andrew S. Nimon, A. Sherehiy, Moath H. A. Alqatamin, Danming Wei, D. Popa","doi":"10.1115/msec2022-85534","DOIUrl":"https://doi.org/10.1115/msec2022-85534","url":null,"abstract":"\u0000 The placement of SMD components is usually performed with Cartesian type robots, a task known as pick-and-place (P&P). Small Selective Compliance Articulated Robot Arm (SCARA) robots are also growing in popularity for this use because of their quick and accurate performance. This paper describes the use of the Lean Robotic Micromanufacturing (LRM) framework applied on a large, 10kg payload, industrial SCARA robot for PCB assembly. The LRM framework guided the precision evaluation of the PCB assembly process and provided a prediction of the placement precision and yield. We experimentally evaluated the repeatability of the system, as well as the resulting collective errors during the assembly. Results confirm that the P&P task can achieve the required assembly tolerance of 200 microns without employing closed-loop visual servoing, therefore considerably decreasing the system complexity and assembly time.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":"35 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86907655","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}
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.
{"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}
Kun Li, J. Zhan, Ruijin Ma, Yingzhi Ren, Jinxin Lin
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.
{"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}
Zoe Alexander, Nathaniel DeVol, Molly Emig, K. Saleeby, T. Feldhausen, Thomas Kurfess, Katherine Fu, Christopher Saldaña
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.
{"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}
This paper introduces the fabrication of wafer-long nanowires using glancing angle deposition (GLAD). GLAD is an advanced physical vapor deposition technique, and it has the unique advantage of creating three-dimensional nanofeature arrays, compared to conventional top-down nanofabrication techniques. Various nanofeatures created by GLAD have been reported, including pillars, springs, chevrons, ribbons, and those structures as templates for creating nanoporous membranes; this paper fills the gap by presenting the creation of nanowires by GLAD. This paper describes the fabrication process by introducing the seeding scheme of corrals. The seed design for GLAD adopts the design rules of corrals of line seeds, and the GLAD parameters are determined by the design of the corrals of line seeds. In the experiment, conventional photolithography is used for creating micro-level widths and heights and wafer-length of line seed corrals. Two GLAD sessions with the target material for the nanowires and the mask material are deposited on the substrate in sequence with different azimuth angles; the nanowires are obtainable by anisotropic etching and removal of the sacrificial layer of corrals of line seeds. The design of the corrals of line seeds and the control of the size of the nanowires are discussed. The nanowires created are potentially applied in sensing applications, for example, the palladium or platinum nanowires can be used for hydrogen sensing.
{"title":"Fabrication of Nanowires Using Glancing Angle Deposition","authors":"C. Qu, S. Mcnamara, K. Walsh","doi":"10.1115/msec2022-83719","DOIUrl":"https://doi.org/10.1115/msec2022-83719","url":null,"abstract":"\u0000 This paper introduces the fabrication of wafer-long nanowires using glancing angle deposition (GLAD). GLAD is an advanced physical vapor deposition technique, and it has the unique advantage of creating three-dimensional nanofeature arrays, compared to conventional top-down nanofabrication techniques. Various nanofeatures created by GLAD have been reported, including pillars, springs, chevrons, ribbons, and those structures as templates for creating nanoporous membranes; this paper fills the gap by presenting the creation of nanowires by GLAD. This paper describes the fabrication process by introducing the seeding scheme of corrals. The seed design for GLAD adopts the design rules of corrals of line seeds, and the GLAD parameters are determined by the design of the corrals of line seeds. In the experiment, conventional photolithography is used for creating micro-level widths and heights and wafer-length of line seed corrals. Two GLAD sessions with the target material for the nanowires and the mask material are deposited on the substrate in sequence with different azimuth angles; the nanowires are obtainable by anisotropic etching and removal of the sacrificial layer of corrals of line seeds. The design of the corrals of line seeds and the control of the size of the nanowires are discussed. The nanowires created are potentially applied in sensing applications, for example, the palladium or platinum nanowires can be used for hydrogen sensing.","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":"73427599","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}
Colton Inkley, David G. Martin, Brennen Clark, N. Crane
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.
{"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}
In the past decade, nanoporous metals have been a point of interest in the scientific community because they exhibit chemical, optical, and mechanical properties that are unique from their bulk counterparts. One of the most prominent method for its synthesis is chemical dealloying. While, under electrolytic conditions, dealloying can use process-inputs such as current density and electrical potential to control the ligament size during its synthesis with excellent reproducibility, electroless methods are plagued by the lack of local control of dealloying rates which introduces batch-to-batch variations in ligament size. Given that powder is a format incompatible with electrolysis, this study shows an approach to safely scale fabrication of spherical porous copper powders containing oxides from gas atomized Cu-Al powders. Additionally, the agglomeration that is commonly associated with porous powder fabrication was addressed by its functionalization with an anionic surfactant and powder washing in both deionized water (polar) and anhydrous ethanol (nonpolar). Additionally, hazards associated with its production scaling such as excessive hydrogen evolution, heat generation due to its high-reactivity and exothermic reaction and pyrophoricity are discussed and addressed. As a result of this study, a robust and scalable approach was developed to produce 100 of grams of porous metal powders.
{"title":"Robust and Scalable Synthesis of High Surface Area Porous Copper Spheriodized Powders by Electroless Chemical Dealloying","authors":"S. Niauzorau, N. Kublik, A. Hasib, B. Azeredo","doi":"10.1115/msec2022-85894","DOIUrl":"https://doi.org/10.1115/msec2022-85894","url":null,"abstract":"\u0000 In the past decade, nanoporous metals have been a point of interest in the scientific community because they exhibit chemical, optical, and mechanical properties that are unique from their bulk counterparts. One of the most prominent method for its synthesis is chemical dealloying. While, under electrolytic conditions, dealloying can use process-inputs such as current density and electrical potential to control the ligament size during its synthesis with excellent reproducibility, electroless methods are plagued by the lack of local control of dealloying rates which introduces batch-to-batch variations in ligament size. Given that powder is a format incompatible with electrolysis, this study shows an approach to safely scale fabrication of spherical porous copper powders containing oxides from gas atomized Cu-Al powders. Additionally, the agglomeration that is commonly associated with porous powder fabrication was addressed by its functionalization with an anionic surfactant and powder washing in both deionized water (polar) and anhydrous ethanol (nonpolar). Additionally, hazards associated with its production scaling such as excessive hydrogen evolution, heat generation due to its high-reactivity and exothermic reaction and pyrophoricity are discussed and addressed. As a result of this study, a robust and scalable approach was developed to produce 100 of grams of porous metal powders.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":"40 5 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82821180","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}
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.
{"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}
A. Alafaghani, Majed Ali, Abdalmageed Almotari, Jian-Qiao Sun, A. Qattawi
Due to the layering nature of additive manufacturing, additively manufactured parts exhibit a unique microstructure and are more susceptible to defects. Post-processing heat treatments of additively manufactured parts have shown great promise in improving their quality and reliability. However, the previous studies presented here demonstrated that additively manufactured parts respond to heat treatments differently compared to their traditional counterparts. This demonstrates a need for models that can predict the influence of different heat treatments on the mechanical behavior of additively manufactured parts. A hybrid approach between data-driven and physically informed models was adopted to model the influence of post-processing heat treatments on the strengthening mechanisms of additively manufactured Inconel 718. This work focuses on Inconel 718 for its common use in additive manufacturing and because it is one of the most studied additively manufactured alloys which resulted in producing more data that can be used to model its behavior.
{"title":"Hybrid Modeling the Influence of Post Processing Heat Treatments on the Strengthening Mechanisms of Additively Manufactured Inconel 718","authors":"A. Alafaghani, Majed Ali, Abdalmageed Almotari, Jian-Qiao Sun, A. Qattawi","doi":"10.1115/msec2022-86354","DOIUrl":"https://doi.org/10.1115/msec2022-86354","url":null,"abstract":"\u0000 Due to the layering nature of additive manufacturing, additively manufactured parts exhibit a unique microstructure and are more susceptible to defects. Post-processing heat treatments of additively manufactured parts have shown great promise in improving their quality and reliability. However, the previous studies presented here demonstrated that additively manufactured parts respond to heat treatments differently compared to their traditional counterparts. This demonstrates a need for models that can predict the influence of different heat treatments on the mechanical behavior of additively manufactured parts. A hybrid approach between data-driven and physically informed models was adopted to model the influence of post-processing heat treatments on the strengthening mechanisms of additively manufactured Inconel 718. This work focuses on Inconel 718 for its common use in additive manufacturing and because it is one of the most studied additively manufactured alloys which resulted in producing more data that can be used to model its behavior.","PeriodicalId":45459,"journal":{"name":"Journal of Micro and Nano-Manufacturing","volume":"314 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78606718","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：