Anup Kulkarni, Vivek C Peddiraju, Subhradeep Chatterjee, Dheepa Srinivasan
Abstract The current work presents an understanding of microstructure and mechanical properties as a function of build geometry and build orientation in Cu-Cr-Zr via the laser powder bed fusion (LPBF) technique. Porosity, microstructure, and mechanical properties have been compared in the as-printed (AP) and heat treated (HT) LPBF Cu-Cr-Zr, between cylindrical and cube geometries, along the longitudinal (L) and transverse (T) build orientations. Varying porosity levels were observed that yielded parts with 96-97% relative density in the AP condition. The AP microstructure demonstrated a hierarchical microstructure, comprising of grains (2.5-100 μm) with a cellular substructure (400-850 nm) and intra-cellular nanoscale (20-60 nm) precipitates enriched in Cu and Zr. Unlike most materials in the AP condition, crystallographic texture was found to be absent; however, very distinct river like patterns highlighted a novel feature of the LPBF Cu-Cr-Zr. Upon solutionizing and aging, Cr precipitates were seen heterogeneously nucleating along cell boundaries (0.5-1.3 μm), causing up to 45% enhancement in the strength and a 4-5% lower ductility. The yield strength along the transverse orientation was 10-16% higher than that of longitudinal orientation, in both the AP and HT conditions. Fracture surface of the tensile samples exhibited micro-voids and cleavage facets and unmelted particles. In spite of the porosity, the overall mechanical properties matched well with those obtained in nearly dense (>99%) samples and the mechanical property debit was less than 10%.
{"title":"Effect of Build Geometry and Porosity in Additively Manufactured CuCrZr","authors":"Anup Kulkarni, Vivek C Peddiraju, Subhradeep Chatterjee, Dheepa Srinivasan","doi":"10.1115/1.4064003","DOIUrl":"https://doi.org/10.1115/1.4064003","url":null,"abstract":"Abstract The current work presents an understanding of microstructure and mechanical properties as a function of build geometry and build orientation in Cu-Cr-Zr via the laser powder bed fusion (LPBF) technique. Porosity, microstructure, and mechanical properties have been compared in the as-printed (AP) and heat treated (HT) LPBF Cu-Cr-Zr, between cylindrical and cube geometries, along the longitudinal (L) and transverse (T) build orientations. Varying porosity levels were observed that yielded parts with 96-97% relative density in the AP condition. The AP microstructure demonstrated a hierarchical microstructure, comprising of grains (2.5-100 μm) with a cellular substructure (400-850 nm) and intra-cellular nanoscale (20-60 nm) precipitates enriched in Cu and Zr. Unlike most materials in the AP condition, crystallographic texture was found to be absent; however, very distinct river like patterns highlighted a novel feature of the LPBF Cu-Cr-Zr. Upon solutionizing and aging, Cr precipitates were seen heterogeneously nucleating along cell boundaries (0.5-1.3 μm), causing up to 45% enhancement in the strength and a 4-5% lower ductility. The yield strength along the transverse orientation was 10-16% higher than that of longitudinal orientation, in both the AP and HT conditions. Fracture surface of the tensile samples exhibited micro-voids and cleavage facets and unmelted particles. In spite of the porosity, the overall mechanical properties matched well with those obtained in nearly dense (>99%) samples and the mechanical property debit was less than 10%.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"51 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135474841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The study included six bitumens, one unmodified and five modified, and their corresponding asphalt mixtures. The first bitumen was the base bitumen and further five variants were made by the authors using the same base bitumen and different combinations of modifiers which included styrene-butadiene-styrene (SBS), Fischer–Tropsch wax (FTW), ethylene vinyl acetate (EVA), reactive elastomeric terpolymer (RET), and natural asphalt (NA). The influence on the fatigue life of bitumen and asphalt due to modification, bitumen rheology, preload, water storage, and aging was studied. A new temperature range was developed—the fatigue-relevant temperature range (FRTR) for specifying fatigue test temperatures for bitumen and asphalt. A new methodology that includes preload and water storage was also done to study the active adhesion behavior between bitumen and aggregates and its influence on fatigue life. Overall, modifications showed positive influence on the fatigue behavior of bitumen and asphalt. Variants E (SBS and RET) and F (SBS and NA) showed the greatest positive influence with an increase in the fatigue life by 500% and 210% for bitumen and 200% and 375% for asphalt respectively. With water storage, the fatigue life reduced by 500% for unmodified asphalt and in the range of 333–1350% for modified ones. Due to aging, the fatigue life reduced from 700% for unmodified and between 700% and 2500% for modified asphalt mixtures.
{"title":"Influence of Multiple Modifications on the Fatigue Behavior of Bitumen and Asphalt Mixtures","authors":"Ronny Sorge, Mrinali Rochlani, Steffen Riedl","doi":"10.1115/1.4063801","DOIUrl":"https://doi.org/10.1115/1.4063801","url":null,"abstract":"Abstract The study included six bitumens, one unmodified and five modified, and their corresponding asphalt mixtures. The first bitumen was the base bitumen and further five variants were made by the authors using the same base bitumen and different combinations of modifiers which included styrene-butadiene-styrene (SBS), Fischer–Tropsch wax (FTW), ethylene vinyl acetate (EVA), reactive elastomeric terpolymer (RET), and natural asphalt (NA). The influence on the fatigue life of bitumen and asphalt due to modification, bitumen rheology, preload, water storage, and aging was studied. A new temperature range was developed—the fatigue-relevant temperature range (FRTR) for specifying fatigue test temperatures for bitumen and asphalt. A new methodology that includes preload and water storage was also done to study the active adhesion behavior between bitumen and aggregates and its influence on fatigue life. Overall, modifications showed positive influence on the fatigue behavior of bitumen and asphalt. Variants E (SBS and RET) and F (SBS and NA) showed the greatest positive influence with an increase in the fatigue life by 500% and 210% for bitumen and 200% and 375% for asphalt respectively. With water storage, the fatigue life reduced by 500% for unmodified asphalt and in the range of 333–1350% for modified ones. Due to aging, the fatigue life reduced from 700% for unmodified and between 700% and 2500% for modified asphalt mixtures.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"12 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135585017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sungmin Yoon, Yasuhiro Kimura, Motoki Uchida, Yang Ju, Yuhki Toku
Abstract Molecular dynamics studies were performed to assess tensile and compressive behaviors at high temperatures up to 1200 °C for nanostructured polycrystalline AlCoCrFeNi high entropy alloy (HEA). As the temperature increased, the tensile yield stress, tensile/compressive ultimate strengths, and elastic modulus decreased, whereas the compressive yield stress remained constant. The temperature dependence of the phase structures (face-centered cubic (FCC) and hexagonal close-packed (HCP)) showed notable features between tension and compression. The HEA underwent FCC → HCP phase transformation when strained under both tension and compression. The evolution of the intrinsic stacking faults (ISFs) and extrinsic stacking faults (ESFs), which underwent FCC → HCP phase transformation, was observed. During compression, the ISFs → ESFs transition produced parallel twins. The evolution of mean dislocation length for the perfect, Shockley, and stair-rod partial dislocations was observed. Changes in the Shockley and stair-rod partial dislocations were observed after experiencing strain. The temperature dependence of the Shockley partial dislocation was high, whereas the stair-rod partial dislocation exhibited low-temperature dependence. From the simulation results, the structural usage of nanostructured polycrystalline AlCoCrFeNi HEA at elevated temperatures is recommended.
{"title":"High Temperature Tensile and Compressive Behaviors of Nanostructured Polycrystalline AlCoCrFeNi High Entropy Alloy: A Molecular Dynamics Study","authors":"Sungmin Yoon, Yasuhiro Kimura, Motoki Uchida, Yang Ju, Yuhki Toku","doi":"10.1115/1.4063802","DOIUrl":"https://doi.org/10.1115/1.4063802","url":null,"abstract":"Abstract Molecular dynamics studies were performed to assess tensile and compressive behaviors at high temperatures up to 1200 °C for nanostructured polycrystalline AlCoCrFeNi high entropy alloy (HEA). As the temperature increased, the tensile yield stress, tensile/compressive ultimate strengths, and elastic modulus decreased, whereas the compressive yield stress remained constant. The temperature dependence of the phase structures (face-centered cubic (FCC) and hexagonal close-packed (HCP)) showed notable features between tension and compression. The HEA underwent FCC → HCP phase transformation when strained under both tension and compression. The evolution of the intrinsic stacking faults (ISFs) and extrinsic stacking faults (ESFs), which underwent FCC → HCP phase transformation, was observed. During compression, the ISFs → ESFs transition produced parallel twins. The evolution of mean dislocation length for the perfect, Shockley, and stair-rod partial dislocations was observed. Changes in the Shockley and stair-rod partial dislocations were observed after experiencing strain. The temperature dependence of the Shockley partial dislocation was high, whereas the stair-rod partial dislocation exhibited low-temperature dependence. From the simulation results, the structural usage of nanostructured polycrystalline AlCoCrFeNi HEA at elevated temperatures is recommended.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"24 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135769507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract A new cellular automaton (CA) program was written in Python language to simulate the random pitting evolution process, which can not only obtain a variety of different corrosion products but also obtain a variety of common corrosion morphologies on the surface of metal pipes, bridge steel members, etc. In addition, commercial finite element (FE) software ABAQUS was redeveloped using Python scripting language, and the FE mesh with the same size as the cellular mesh was established based on the consistent mesh algorithm, which ensured the efficiency and accuracy of the cyclic iterative algorithm. The stress and strain fields were calculated in real-time by applying the force load, the dissolution probability parameter P was updated in Python according to the force-chemical coupling model, and a new corrosion morphology was obtained in Python. At the same time, the birth and death element method was applied in ABAQUS to kill the corrosion elements in this iterative step simultaneously, and the new stress-strain field was recalculated in ABAQUS. The established consistent grid modeling strategy and cyclic iterative algorithm can significantly improve the solving efficiency of pitting evolution under the coupled action of corrosive medium and load. The results show that the stress concentration caused by pit expansion and the corrosion acceleration effect dominated by plastic deformation will promote each other, leading to the continuous growth of pitted pits. The established modeling strategy and cyclic iterative algorithm can significantly improve the solving efficiency of pitting evolution under the coupled action of corrosive medium and load.
{"title":"Simulation of Pitting Corrosion Under Stress Based on Cellular Automata and Finite Element Method","authors":"Ying Wang, Haoran Shi","doi":"10.1115/1.4063850","DOIUrl":"https://doi.org/10.1115/1.4063850","url":null,"abstract":"Abstract A new cellular automaton (CA) program was written in Python language to simulate the random pitting evolution process, which can not only obtain a variety of different corrosion products but also obtain a variety of common corrosion morphologies on the surface of metal pipes, bridge steel members, etc. In addition, commercial finite element (FE) software ABAQUS was redeveloped using Python scripting language, and the FE mesh with the same size as the cellular mesh was established based on the consistent mesh algorithm, which ensured the efficiency and accuracy of the cyclic iterative algorithm. The stress and strain fields were calculated in real-time by applying the force load, the dissolution probability parameter P was updated in Python according to the force-chemical coupling model, and a new corrosion morphology was obtained in Python. At the same time, the birth and death element method was applied in ABAQUS to kill the corrosion elements in this iterative step simultaneously, and the new stress-strain field was recalculated in ABAQUS. The established consistent grid modeling strategy and cyclic iterative algorithm can significantly improve the solving efficiency of pitting evolution under the coupled action of corrosive medium and load. The results show that the stress concentration caused by pit expansion and the corrosion acceleration effect dominated by plastic deformation will promote each other, leading to the continuous growth of pitted pits. The established modeling strategy and cyclic iterative algorithm can significantly improve the solving efficiency of pitting evolution under the coupled action of corrosive medium and load.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135570128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract To study the corrosion characteristic of 20G steel in saline circumstances with sodium sulfate (Na2SO4), a series of corrosion experiments are implemented on a novel setup. The corroded steel samples are analyzed by XPS and XRD. The results indicate that the effect of salinity on corrosion products in the gas phase is greater than that in the liquid phase. FeOOH is easier to form in the liquid phase than in the gas phase. The salinity of steam could promote the generation of Fe2O3. The relative content of Fe2O3 within the corrosion products that contained Fe in gas/liquid phase increases from 49.68%/36.30% (Na2SO4 concentration in solution, c = 0) to 95.70%/74.55%, separately (c = 4 g L−1). The salinity has an inhibiting effect on the generation of FeOOH. In the deionized water, the relative contents of FeOOH within the corrosion products that contained Fe are 36.01% (gas phase) and 56.43% (liquid phase), respectively. FeOOH hardly occurs as c = 4 g L−1. For corroded surface in Na2SO4 deposit, the main compositions detected are iron oxides (Fe2O3 and Fe3O4) and iron (Fe).
摘要为了研究20G钢在盐态硫酸钠(Na2SO4)腐蚀条件下的腐蚀特性，在一种新型装置上进行了一系列腐蚀实验。用XPS和XRD对腐蚀钢试样进行了分析。结果表明，盐度对气相腐蚀产物的影响大于液相腐蚀产物。FeOOH在液相中比在气相中更容易形成。水蒸气的盐度对Fe2O3的生成有促进作用。含铁腐蚀产物中Fe2O3的相对含量分别从49.68%/36.30%(溶液中Na2SO4浓度，c = 0)增加到95.70%/74.55% (c = 4 g L−1)。盐度对FeOOH的生成有抑制作用。在去离子水中，含铁腐蚀产物中FeOOH的相对含量分别为36.01%(气相)和56.43%(液相)。当c = 4 g L−1时，FeOOH几乎不发生。Na2SO4镀层腐蚀表面检测到的主要成分为氧化铁(Fe2O3和Fe3O4)和铁(Fe)。
{"title":"Corrosion Behavior of 20G Steel in Saline (Na2SO4) Circumstances at High Temperature/Pressure","authors":"Ruiyu Li, Bing Bai, Lei Deng, Defu Che","doi":"10.1115/1.4063666","DOIUrl":"https://doi.org/10.1115/1.4063666","url":null,"abstract":"Abstract To study the corrosion characteristic of 20G steel in saline circumstances with sodium sulfate (Na2SO4), a series of corrosion experiments are implemented on a novel setup. The corroded steel samples are analyzed by XPS and XRD. The results indicate that the effect of salinity on corrosion products in the gas phase is greater than that in the liquid phase. FeOOH is easier to form in the liquid phase than in the gas phase. The salinity of steam could promote the generation of Fe2O3. The relative content of Fe2O3 within the corrosion products that contained Fe in gas/liquid phase increases from 49.68%/36.30% (Na2SO4 concentration in solution, c = 0) to 95.70%/74.55%, separately (c = 4 g L−1). The salinity has an inhibiting effect on the generation of FeOOH. In the deionized water, the relative contents of FeOOH within the corrosion products that contained Fe are 36.01% (gas phase) and 56.43% (liquid phase), respectively. FeOOH hardly occurs as c = 4 g L−1. For corroded surface in Na2SO4 deposit, the main compositions detected are iron oxides (Fe2O3 and Fe3O4) and iron (Fe).","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134974965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Short carbon fiber (SCF) reinforced thermoplastic composites (SCFRTCs) are attracting broad attention in various fields for their excellent mechanical properties. The fracture toughness, an essential characteristic of the resistance of materials to crack propagation, is considered a critical aspect of the long-term performance of SCFRTCs structures. The fracture toughness of SCFRTCs depends on two competing mechanisms: the interface between SCFs and polymer matrix may promote crack initiation, while the SCFs hinder the crack propagation. In this study, the fracture toughness of SCFRTCs with varying SCFs fractions is first measured by a three-point bending test. The results show that adding SCFs effectively improves the fracture toughness of SCFRTCs, and an increase of up to 73.7% is observed at the SCFs fraction of 9.80 wt%. In addition, it is found that the fracture toughness decreases slightly but is more stable after heat treatment. Subsequently, the full field strain around the crack tip is analyzed by Digital Image Correlation (DIC), and the strain level significantly decreases after adding SCFs. Moreover, the dynamic crack propagation is observed by DIC, and the crack initiation load is obtained successfully to verify the large deformation during crack initiation. Compared with the smooth fracture surface of the HDPE specimen, the fracture surface of the SCFRTCs specimen is much rougher, and obvious bridging SCFs are observed. The larger specific surface area and bridging SCFs of fracture surface absorb more energy during the fracture of SCFRTCs specimen, thus explaining the improved fracture toughness of SCFRTCs.
{"title":"Evaluation of the Fracture Toughness of Short Carbon Fiber Reinforced Thermoplastic Composites","authors":"Jianfeng Shi, Xinwei Zong, weili jiang, Riwu Yao, Jinyang Zheng","doi":"10.1115/1.4063667","DOIUrl":"https://doi.org/10.1115/1.4063667","url":null,"abstract":"Abstract Short carbon fiber (SCF) reinforced thermoplastic composites (SCFRTCs) are attracting broad attention in various fields for their excellent mechanical properties. The fracture toughness, an essential characteristic of the resistance of materials to crack propagation, is considered a critical aspect of the long-term performance of SCFRTCs structures. The fracture toughness of SCFRTCs depends on two competing mechanisms: the interface between SCFs and polymer matrix may promote crack initiation, while the SCFs hinder the crack propagation. In this study, the fracture toughness of SCFRTCs with varying SCFs fractions is first measured by a three-point bending test. The results show that adding SCFs effectively improves the fracture toughness of SCFRTCs, and an increase of up to 73.7% is observed at the SCFs fraction of 9.80 wt%. In addition, it is found that the fracture toughness decreases slightly but is more stable after heat treatment. Subsequently, the full field strain around the crack tip is analyzed by Digital Image Correlation (DIC), and the strain level significantly decreases after adding SCFs. Moreover, the dynamic crack propagation is observed by DIC, and the crack initiation load is obtained successfully to verify the large deformation during crack initiation. Compared with the smooth fracture surface of the HDPE specimen, the fracture surface of the SCFRTCs specimen is much rougher, and obvious bridging SCFs are observed. The larger specific surface area and bridging SCFs of fracture surface absorb more energy during the fracture of SCFRTCs specimen, thus explaining the improved fracture toughness of SCFRTCs.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134977793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract 3D printing is a layer by layer deposition process, which results in highly anisotropic structures, and contain interfaces. Complex shapes manufactured by 3D printing carry defects. Complete elimination of these defects and interfaces is not possible, and these defects degrade the mechanical properties. In the present study, mechanical properties of printed dog bone samples are quantified as a function of building parameters, in particular, filling patterns, raster angle, and orientation of build direction with respect to that of loading, in polylactic acid (PLA). The tensile strength of 3D printed PLA is the same for hexagonal and linear pattern filling when build direction is along thickness and width, and failure was initiated at the defects in the structure, while better overall toughness is offered by hexagonal pattern filling. Build direction along specimen gauge length gives very low tensile strength and toughness, and failure happens between the printing layers. To minimize the defects especially near the grip section, cuboid sample were first deposited, and micro-machined by laser into dog bone shape to perform tension test. Tensile strength and elastic modulus of micro-machined samples are surprisingly lower, while failure strain is highest among line filling printed samples. Damage resistance was quantified in terms of work of fracture, and hexagonal filling provided better damage resistance than line filling patterns for conditions of 0º raster angle with respect to the crack whereas line filling with 45º and 90º raster angle tolerated damage better than hexagonal filling.
{"title":"Mechanical Properties and Fracture Resistance of 3D Printed PLA","authors":"Deepesh Yadav, Balila Nagamani Jaya","doi":"10.1115/1.4063614","DOIUrl":"https://doi.org/10.1115/1.4063614","url":null,"abstract":"Abstract 3D printing is a layer by layer deposition process, which results in highly anisotropic structures, and contain interfaces. Complex shapes manufactured by 3D printing carry defects. Complete elimination of these defects and interfaces is not possible, and these defects degrade the mechanical properties. In the present study, mechanical properties of printed dog bone samples are quantified as a function of building parameters, in particular, filling patterns, raster angle, and orientation of build direction with respect to that of loading, in polylactic acid (PLA). The tensile strength of 3D printed PLA is the same for hexagonal and linear pattern filling when build direction is along thickness and width, and failure was initiated at the defects in the structure, while better overall toughness is offered by hexagonal pattern filling. Build direction along specimen gauge length gives very low tensile strength and toughness, and failure happens between the printing layers. To minimize the defects especially near the grip section, cuboid sample were first deposited, and micro-machined by laser into dog bone shape to perform tension test. Tensile strength and elastic modulus of micro-machined samples are surprisingly lower, while failure strain is highest among line filling printed samples. Damage resistance was quantified in terms of work of fracture, and hexagonal filling provided better damage resistance than line filling patterns for conditions of 0º raster angle with respect to the crack whereas line filling with 45º and 90º raster angle tolerated damage better than hexagonal filling.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135739273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study used a suitable solvent such as deionized water and aqueous acetic acid to dissolve completely polymer blends such as gelatin: chitosan: pullulan (G: CS: PUL) with mixing ratios of 80:10:10, 60:20:20, 40:30:30, 20:40:40 respectively. The properties of natural polymer mixtures, viscosity, surface tension, and electrical conductivity were examined, and the fiber diameter and nanofiber diameters distribution were measured. Increasing the gelatin content from 20% to 80% in the G: CS: PUL increases the properties of biopolymer solutions, such as viscosity, surface tension, and electrical conductivity 157%, 14%, and 37%, respectively. In addition, increasing the gelatin content reduces the contact angle by 55%. In other words, the average diameter of the nanofibers increased from 91.177 ± 27.162 to 212.46 ± 67.91 nm with the increase of the gelatin content by 40 % - 100% in the blends and obtaining uniform fibers without beads, which enhanced the ability of nanofibers for releasing into the aqueous media and enhancing their use in packaging food such as (80:10:10 and 60:20:20). Moreover the blend ratio 60:30:30 (G:CS: PUL) had better resistance to bacterial growth, the inhibition zone diameters were 26 and 23 mm for E. coli and S. aureus and had better average crystalline size and crystallinity.
{"title":"Natural Biopolymer-hydrogels Nanofibers for Antibacterial Applications","authors":"S. Habeeb, Mushreq Kareem Abdulkadhim","doi":"10.1115/1.4063329","DOIUrl":"https://doi.org/10.1115/1.4063329","url":null,"abstract":"\u0000 This study used a suitable solvent such as deionized water and aqueous acetic acid to dissolve completely polymer blends such as gelatin: chitosan: pullulan (G: CS: PUL) with mixing ratios of 80:10:10, 60:20:20, 40:30:30, 20:40:40 respectively. The properties of natural polymer mixtures, viscosity, surface tension, and electrical conductivity were examined, and the fiber diameter and nanofiber diameters distribution were measured. Increasing the gelatin content from 20% to 80% in the G: CS: PUL increases the properties of biopolymer solutions, such as viscosity, surface tension, and electrical conductivity 157%, 14%, and 37%, respectively. In addition, increasing the gelatin content reduces the contact angle by 55%. In other words, the average diameter of the nanofibers increased from 91.177 ± 27.162 to 212.46 ± 67.91 nm with the increase of the gelatin content by 40 % - 100% in the blends and obtaining uniform fibers without beads, which enhanced the ability of nanofibers for releasing into the aqueous media and enhancing their use in packaging food such as (80:10:10 and 60:20:20). Moreover the blend ratio 60:30:30 (G:CS: PUL) had better resistance to bacterial growth, the inhibition zone diameters were 26 and 23 mm for E. coli and S. aureus and had better average crystalline size and crystallinity.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63503911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shreehard Sahu, B. Kumar, S. Sahoo, Nagamani Jaya Balila, D. Srinivasan
The Co-based superalloy Mar M 509, known for its high-temperature oxidation and hot corrosion resistance, is processed via laser powder bed fusion (LPBF). Microstructure and mechanical properties of Mar M 509 in as-printed (As-P) and heat-treated (HT) states are compared based on two build orientations (longitudinal (L) and transverse (T)) to establish structure-property links with heat treatment. The As-P condition displays a distinct cellular microstructure (500-600 nm) with 50-60 nm carbide particles adorning cell boundaries. Longitudinal (L) build has columnar grains (8-35 μm along major axis) with a grain aspect ratio of 4, while transverse (T) orientation exhibits equiaxed, bimodal microstructure (5-10 μm and 15-25 μm grain sizes). Strong <001> texture is noted in L. Mechanical properties at room temperature differ between L and T; T (569±12HV) has 15% higher hardness compared to L (489±18HV) and 34% higher 0.2% yield strength (YS), but 30% lower elongation than L. Post a short heat treatment cycle at 1250°C, weld bead structure and cell boundaries break down. Both L (25-33 μm along major axis) and T orientations (5-42 μm) experience grain growth, and carbides coarsen (250-350 nm). Post-heat treatment, dislocation density decreases, indicating recrystallization; lattice parameter of matrix reduces, implying solute depletion contributing to carbide enrichment. Yield strength drops from 860 MPa to 740 MPa in L and from 1150 MPa to 840 MPa in T, with ductility rising from 14% to 23% in L.
钴基高温合金Mar M 509以其耐高温氧化和热腐蚀性而闻名，它是通过激光粉末床熔融（LPBF）处理的。基于两个构建方向（纵向（L）和横向（T）），比较了Mar M 509在印刷态（as-P）和热处理态（HT）下的微观结构和力学性能，以建立与热处理的结构-性能联系。As-P条件显示出明显的细胞微结构（500-600nm），其中50-60nm的碳化物颗粒装饰细胞边界。纵向（L）结构具有晶粒纵横比为4的柱状晶粒（沿主轴8-35μm），而横向（T）取向表现出等轴双峰微观结构（5-10μm和15-25μm晶粒尺寸）。L具有强烈的织构。室温下L和T的机械性能不同；与L（489±18HV）相比，T（569±12HV）的硬度高出15%，屈服强度（YS）高出34%，但伸长率比L低30%。在1250°C的短热处理循环后，焊道结构和细胞边界破裂。L（沿主轴25-33μm）和T取向（5-42μm）都经历晶粒生长，碳化物粗化（250-350 nm）。热处理后，位错密度降低，表明再结晶；基体晶格参数降低，表明溶质贫化有助于碳化物富集。屈服强度从L的860MPa下降到740MPa，从T的1150MPa下降到840MPa，延展性从L的14%上升到23%。
{"title":"Microstructural Evolution and Room Temperature Mechanical Properties in Additively Manufactured Mar M 509 with Short Cycle Heat Treatment.","authors":"Shreehard Sahu, B. Kumar, S. Sahoo, Nagamani Jaya Balila, D. Srinivasan","doi":"10.1115/1.4063257","DOIUrl":"https://doi.org/10.1115/1.4063257","url":null,"abstract":"\u0000 The Co-based superalloy Mar M 509, known for its high-temperature oxidation and hot corrosion resistance, is processed via laser powder bed fusion (LPBF). Microstructure and mechanical properties of Mar M 509 in as-printed (As-P) and heat-treated (HT) states are compared based on two build orientations (longitudinal (L) and transverse (T)) to establish structure-property links with heat treatment. The As-P condition displays a distinct cellular microstructure (500-600 nm) with 50-60 nm carbide particles adorning cell boundaries. Longitudinal (L) build has columnar grains (8-35 μm along major axis) with a grain aspect ratio of 4, while transverse (T) orientation exhibits equiaxed, bimodal microstructure (5-10 μm and 15-25 μm grain sizes). Strong <001> texture is noted in L. Mechanical properties at room temperature differ between L and T; T (569±12HV) has 15% higher hardness compared to L (489±18HV) and 34% higher 0.2% yield strength (YS), but 30% lower elongation than L. Post a short heat treatment cycle at 1250°C, weld bead structure and cell boundaries break down. Both L (25-33 μm along major axis) and T orientations (5-42 μm) experience grain growth, and carbides coarsen (250-350 nm). Post-heat treatment, dislocation density decreases, indicating recrystallization; lattice parameter of matrix reduces, implying solute depletion contributing to carbide enrichment. Yield strength drops from 860 MPa to 740 MPa in L and from 1150 MPa to 840 MPa in T, with ductility rising from 14% to 23% in L.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44664472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andres Felipe Pava, Mateo Duarte Garcia, Sara N. Herrera, J. Meza, J. Herrera-Ramirez, C. Isaza M.
Polyvinyl alcohol (PVA) was investigated as a vehicle for incorporating thermally reduced graphene oxides (TRGOs) into metal matrix composites (MMCs). The TRGOs were synthesized using the modified Hummers' method and characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The PVA/TRGOs nanocomposites were synthesized using the solution mixing technique. The dispersion qualification and quantification of TRGOs in PVA were evaluated through tension and nanoindentation tests, as well as elastic modulus mapping by nanoindentation. The results demonstrated a good dispersion of TRGOs in the PVA matrix, resulting in exceptional mechanical properties. The dispersion time and energy variables were carefully controlled, leading to a good dispersion degree verified by the quantification analysis. Furthermore, preliminary studies confirmed the effectiveness of PVA as an inclusion vehicle for nanoreinforcements in metallic matrices.
{"title":"Potential use of polyvinyl alcohol as an effective inclusion vehicle of thermally reduced graphene oxides in nanoreinforced aluminum matrix composites","authors":"Andres Felipe Pava, Mateo Duarte Garcia, Sara N. Herrera, J. Meza, J. Herrera-Ramirez, C. Isaza M.","doi":"10.1115/1.4063208","DOIUrl":"https://doi.org/10.1115/1.4063208","url":null,"abstract":"\u0000 Polyvinyl alcohol (PVA) was investigated as a vehicle for incorporating thermally reduced graphene oxides (TRGOs) into metal matrix composites (MMCs). The TRGOs were synthesized using the modified Hummers' method and characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The PVA/TRGOs nanocomposites were synthesized using the solution mixing technique. The dispersion qualification and quantification of TRGOs in PVA were evaluated through tension and nanoindentation tests, as well as elastic modulus mapping by nanoindentation. The results demonstrated a good dispersion of TRGOs in the PVA matrix, resulting in exceptional mechanical properties. The dispersion time and energy variables were carefully controlled, leading to a good dispersion degree verified by the quantification analysis. Furthermore, preliminary studies confirmed the effectiveness of PVA as an inclusion vehicle for nanoreinforcements in metallic matrices.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43398006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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