The laser welding of Cu–Al alloys for battery applications in the automotive industry presents significant challenges due to the high reflectivity of copper. Inadequate bonding and low mechanical strength may occur when the laser radiation is directed toward the copper side in an overlap configuration welding. To tackle these challenges, a laser surface treatment technique is implemented to enhance the absorption characteristics and overcome the reflective nature of the copper material. However, elevating the surface roughness and heat-energy input over threshold values leads to heightened temperature and extreme weld. This phenomenon escalates the formation of detrimental intermetallic compounds (IMC), creating defects like cracks and porosity. Metallurgical analysis, which is time-consuming and expensive, is usually used in studies to detect these phases and defects. However, to comprehensively evaluate the weld quality and discern the impact of surface structure, adopting a more innovative approach that replaces conventional cross-sectional metallography is essential. This article proposes a model based on the image feature extraction of the welds to study the effect of the laser-based structure and the other laser parameters. It can detect defects and identify the weld quality by weld classification. However, due to the complexity of the photo features, the system requires image processing and a convolutional neural network (CNN). Results show that the predictive model based on trained data can detect different weld categories and recognize unstable welds. The project aims to use a monitoring model to guarantee optimized and high-quality weld series production. To achieve this, a deeper study of the parameters and the microstructure of the weld is utilized, and the CNN model analyzes the features of 1310 pieces of weld photos with different weld parameters.
{"title":"Data-driven analysis of surface roughness influence on weld quality and defect formation in laser welding of Cu–Al","authors":"Mohammadhossein Norouzian, Mahdi Amne Elahi, Marcus Koch, Reza Mahin Zaeem, Slawomir Kedziora","doi":"10.1177/14644207241236138","DOIUrl":"https://doi.org/10.1177/14644207241236138","url":null,"abstract":"The laser welding of Cu–Al alloys for battery applications in the automotive industry presents significant challenges due to the high reflectivity of copper. Inadequate bonding and low mechanical strength may occur when the laser radiation is directed toward the copper side in an overlap configuration welding. To tackle these challenges, a laser surface treatment technique is implemented to enhance the absorption characteristics and overcome the reflective nature of the copper material. However, elevating the surface roughness and heat-energy input over threshold values leads to heightened temperature and extreme weld. This phenomenon escalates the formation of detrimental intermetallic compounds (IMC), creating defects like cracks and porosity. Metallurgical analysis, which is time-consuming and expensive, is usually used in studies to detect these phases and defects. However, to comprehensively evaluate the weld quality and discern the impact of surface structure, adopting a more innovative approach that replaces conventional cross-sectional metallography is essential. This article proposes a model based on the image feature extraction of the welds to study the effect of the laser-based structure and the other laser parameters. It can detect defects and identify the weld quality by weld classification. However, due to the complexity of the photo features, the system requires image processing and a convolutional neural network (CNN). Results show that the predictive model based on trained data can detect different weld categories and recognize unstable welds. The project aims to use a monitoring model to guarantee optimized and high-quality weld series production. To achieve this, a deeper study of the parameters and the microstructure of the weld is utilized, and the CNN model analyzes the features of 1310 pieces of weld photos with different weld parameters.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"80 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140019716","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}
Pub Date : 2024-03-01DOI: 10.1177/14644207241236277
Eugenio Dragoni
The article investigates by finite elements the bending stresses around a centre transverse circular hole in straight bars with rectangular or circular cross-section. Four loading conditions are considered, pure bending and three variants of three-point bending (load concentrated on the bar surface above the hole, load directly applied to the hole as uniform pressure, load applied to the hole through a connecting pin). Mostly, the hole diameter is one-third of the section height and one-twentieth of the beam length. Holes of one-fourth and one half of the section on several beam lengths are also investigated for the flat bar in three-point bending to appraise the sensitivity to aspect ratios. The results show that, in all cases, the notch effect is mildly detrimental to the stress distribution and can even be beneficial in comparison with the unperforated bar. This is because the hole increases the stresses around the neutral axis, where the stresses are naturally low, thus taking away stresses from the surface where the bending stresses are naturally highest. The design of pivoted flexural machine elements like levers, yokes and balance arms can take advantage from this evidence.
{"title":"Bending stresses in straight bars with a transverse centre hole: A case of beneficial notch effect?","authors":"Eugenio Dragoni","doi":"10.1177/14644207241236277","DOIUrl":"https://doi.org/10.1177/14644207241236277","url":null,"abstract":"The article investigates by finite elements the bending stresses around a centre transverse circular hole in straight bars with rectangular or circular cross-section. Four loading conditions are considered, pure bending and three variants of three-point bending (load concentrated on the bar surface above the hole, load directly applied to the hole as uniform pressure, load applied to the hole through a connecting pin). Mostly, the hole diameter is one-third of the section height and one-twentieth of the beam length. Holes of one-fourth and one half of the section on several beam lengths are also investigated for the flat bar in three-point bending to appraise the sensitivity to aspect ratios. The results show that, in all cases, the notch effect is mildly detrimental to the stress distribution and can even be beneficial in comparison with the unperforated bar. This is because the hole increases the stresses around the neutral axis, where the stresses are naturally low, thus taking away stresses from the surface where the bending stresses are naturally highest. The design of pivoted flexural machine elements like levers, yokes and balance arms can take advantage from this evidence.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"50 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140019776","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}
In this article, ultrasonic welding of glass fiber-reinforced thermosetting polymers which were surface-treated by laser engraving, is investigated. Composite samples were prepared by hand lay-up method. In the next step, surface treatment of the composite samples was performed by means of a high-power laser confirming two grooved and circular patterns. Polymethylmethacrylate and polypropylene as the amorphous and semicrystalline thermoplastic intermediate layers were incorporated to create a joining between the two thermoset parts. Besides, the welding time was considered in the three different levels. In order to investigate the microstructure of the welding zone, scanning electron microscopy analysis were accomplished. Besides, lap-shear tests were performed so as to evaluate the mechanical performances of the welded parts. Morphological studies indicated that in the surface-treated samples, the penetration of the intermediate material into the welded parts is much higher than neat samples and this leads to the superior interaction between the coupling layer and the surface-treated parts. Confirming the morphological outcomes, the results of the lap-shear tests specified that the application of surface treatment using laser engraving has increased the laps-shear strength almost 5.5 times compared to the samples without preparation.
{"title":"Improving the quality of the ultrasonic welded thermoset-based composites using laser surface treatment","authors":"Hamed Tirband, Davood Akbari, Pouya Faraji Kalajahi","doi":"10.1177/14644207241230757","DOIUrl":"https://doi.org/10.1177/14644207241230757","url":null,"abstract":"In this article, ultrasonic welding of glass fiber-reinforced thermosetting polymers which were surface-treated by laser engraving, is investigated. Composite samples were prepared by hand lay-up method. In the next step, surface treatment of the composite samples was performed by means of a high-power laser confirming two grooved and circular patterns. Polymethylmethacrylate and polypropylene as the amorphous and semicrystalline thermoplastic intermediate layers were incorporated to create a joining between the two thermoset parts. Besides, the welding time was considered in the three different levels. In order to investigate the microstructure of the welding zone, scanning electron microscopy analysis were accomplished. Besides, lap-shear tests were performed so as to evaluate the mechanical performances of the welded parts. Morphological studies indicated that in the surface-treated samples, the penetration of the intermediate material into the welded parts is much higher than neat samples and this leads to the superior interaction between the coupling layer and the surface-treated parts. Confirming the morphological outcomes, the results of the lap-shear tests specified that the application of surface treatment using laser engraving has increased the laps-shear strength almost 5.5 times compared to the samples without preparation.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"18 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140019897","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}
Pub Date : 2024-02-29DOI: 10.1177/14644207241234395
Longbiao Li, Kang Su, Zhaoke Chen, Zhongwei Zhang, Xiang Xiong
In this paper, the influence of interphase type (i.e. single-phase (PyC) and co-deposited (PyC+SiC)) and thickness (i.e. 300, 600, 1000, and 2000 nm) on the interface properties and damage evolution of mini-C/SiC composites under cyclic loading/unloading tension was investigated. The micromechanical constitutive model was adopted to derive the damage parameter of inverse tangent modulus (ITM) and perform the hysteresis analysis to estimate the interface properties of the mini-C/SiC composites with large debonding energy. Experimental damage evolution of the ITMs with unloading or reloading stress was analyzed for different interphase types and thickness. The interface properties (e.g. the interface debonding stress and interface debonding energy) were obtained through the hysteresis analysis. Relationships between the loading/unloading ITMs, interface properties, and interphase type and thickness were established.
{"title":"Influence of interphase type and thickness on the interface properties and tensile damage evolution of C/SiC composites","authors":"Longbiao Li, Kang Su, Zhaoke Chen, Zhongwei Zhang, Xiang Xiong","doi":"10.1177/14644207241234395","DOIUrl":"https://doi.org/10.1177/14644207241234395","url":null,"abstract":"In this paper, the influence of interphase type (i.e. single-phase (PyC) and co-deposited (PyC+SiC)) and thickness (i.e. 300, 600, 1000, and 2000 nm) on the interface properties and damage evolution of mini-C/SiC composites under cyclic loading/unloading tension was investigated. The micromechanical constitutive model was adopted to derive the damage parameter of inverse tangent modulus (ITM) and perform the hysteresis analysis to estimate the interface properties of the mini-C/SiC composites with large debonding energy. Experimental damage evolution of the ITMs with unloading or reloading stress was analyzed for different interphase types and thickness. The interface properties (e.g. the interface debonding stress and interface debonding energy) were obtained through the hysteresis analysis. Relationships between the loading/unloading ITMs, interface properties, and interphase type and thickness were established.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"3 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140002028","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}
Pub Date : 2024-02-28DOI: 10.1177/14644207241233889
RM Carneiro Neto, A Akhavan-Safar, EM Sampaio, BD Simões, LL Vignoli, LFM da Silva
This review paper provides an exploration of various facets of creep behaviour in adhesives and adhesive joints, encompassing experimental procedures, prediction models, influential parameters and strategies to enhance resistance. The discussion extends to the interplay between fatigue and creep, emphasising recent advances over the last two decades. While avoiding redundancy with prior work on temperature and moisture degradation, the paper articulates connections between topics for a better understanding. A critical examination of load levels reveals that small variations significantly impact the creep life of adhesive joints, particularly prominent with epoxy adhesives. The adhesive type, joint geometry and substrate material are scrutinised, revealing distinct impacts on creep behaviour. The study underscores the critical role of adhesive thickness and overlap length, emphasising their relevance in determining the time to failure in bonded joints under creep conditions. Notably, the substrate material’s role is highlighted. As the review delves into unexplored dimensions, it calls for further research to bridge existing gaps and refine our understanding of tertiary creep and time until failure.
{"title":"Creep behaviour of adhesively bonded joints: A comprehensive review","authors":"RM Carneiro Neto, A Akhavan-Safar, EM Sampaio, BD Simões, LL Vignoli, LFM da Silva","doi":"10.1177/14644207241233889","DOIUrl":"https://doi.org/10.1177/14644207241233889","url":null,"abstract":"This review paper provides an exploration of various facets of creep behaviour in adhesives and adhesive joints, encompassing experimental procedures, prediction models, influential parameters and strategies to enhance resistance. The discussion extends to the interplay between fatigue and creep, emphasising recent advances over the last two decades. While avoiding redundancy with prior work on temperature and moisture degradation, the paper articulates connections between topics for a better understanding. A critical examination of load levels reveals that small variations significantly impact the creep life of adhesive joints, particularly prominent with epoxy adhesives. The adhesive type, joint geometry and substrate material are scrutinised, revealing distinct impacts on creep behaviour. The study underscores the critical role of adhesive thickness and overlap length, emphasising their relevance in determining the time to failure in bonded joints under creep conditions. Notably, the substrate material’s role is highlighted. As the review delves into unexplored dimensions, it calls for further research to bridge existing gaps and refine our understanding of tertiary creep and time until failure.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"8 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140002031","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}
Pub Date : 2024-02-27DOI: 10.1177/14644207241232233
T Borgert, D Köhler, E. Wiens, R Kupfer, J Troschitz, W Homberg, M Gude
Lightweight design by using low-density and load-adapted materials can reduce the weight of vehicles and the emissions generated during operation. However, the usage of different materials requires innovative joining technologies with increased versatility. In this investigation, the focus is on describing and characterising the failure behaviour of connections manufactured by an innovative thermomechanical joining process with adaptable auxiliary joining elements in single-lap tensile-shear tests. In order to analyse the failure development in detail, the specimens are investigated using in-situ computed tomography (in-situ CT). Here, the tensile-shear test is interrupted at points of interest and CT scans are conducted under load. In addition, the interrupted in-situ testing procedure is validated by comparing the loading behaviour with conventional continuous tensile-shear tests. The results of the in-situ investigations of joints with varying material combinations clearly describe the cause of failure, allowing conclusions towards an improved joint design.
{"title":"In-situ computed tomography analysis of the failure mechanisms of thermomechanically manufactured joints with auxiliary joining element","authors":"T Borgert, D Köhler, E. Wiens, R Kupfer, J Troschitz, W Homberg, M Gude","doi":"10.1177/14644207241232233","DOIUrl":"https://doi.org/10.1177/14644207241232233","url":null,"abstract":"Lightweight design by using low-density and load-adapted materials can reduce the weight of vehicles and the emissions generated during operation. However, the usage of different materials requires innovative joining technologies with increased versatility. In this investigation, the focus is on describing and characterising the failure behaviour of connections manufactured by an innovative thermomechanical joining process with adaptable auxiliary joining elements in single-lap tensile-shear tests. In order to analyse the failure development in detail, the specimens are investigated using in-situ computed tomography (in-situ CT). Here, the tensile-shear test is interrupted at points of interest and CT scans are conducted under load. In addition, the interrupted in-situ testing procedure is validated by comparing the loading behaviour with conventional continuous tensile-shear tests. The results of the in-situ investigations of joints with varying material combinations clearly describe the cause of failure, allowing conclusions towards an improved joint design.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"1 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140001945","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}
Pub Date : 2024-02-26DOI: 10.1177/14644207241235784
Palanivendhan Murugadoss, Chandradass Jeyaseelan
The A383 aluminum matrix composites (AMCs) are prominent automotive materials owing to their low-density yet high-strength nature. However, the conventional casting techniques, exorbitant price, and scarce supply of traditional ceramic reinforcements remain challenging. This research countermeasure the challenges by hybridizing the A383 with industrial marble dust (MD) and hexagonal boron nitride (hBN) through the stir-cum-squeeze casting technique. A constant proportion (4 wt%) of MD waste and varying proportions of hBN (1.5, 3, 4.5, and 6 wt%) were used to reinforce A383 alloy to improve its physio-mechanical characteristics. Stir-cum-squeeze casting enables homogenous dispersion of reinforcement particles within the matrix, resulting in improved interfacial bonding. Optimal results were achieved for A383 alloy reinforced with 4 wt% of MD and 6 wt% hBN, ensuring balanced tribo-mechanical characteristics against the as-casted A383. The hardness value increased by 40.8%, while the compression and tensile strength increased by 30.8% and 115.8%, respectively. Non-destructive testing confirms the effective reduction of porosity in the stir-cum-squeeze-cast composites. Moreover, the hybrid composites exhibit improved corrosion resistance by 32.18% after 72 h of testing. Additionally, the hybrid composites demonstrate a wear rate reduction of 54.35%.
{"title":"Enhancing tribo-mechanical and corrosion properties of A383 aluminum matrix composites through stir-cum-squeeze casting with marble dust and hexagonal boron nitride reinforcement","authors":"Palanivendhan Murugadoss, Chandradass Jeyaseelan","doi":"10.1177/14644207241235784","DOIUrl":"https://doi.org/10.1177/14644207241235784","url":null,"abstract":"The A383 aluminum matrix composites (AMCs) are prominent automotive materials owing to their low-density yet high-strength nature. However, the conventional casting techniques, exorbitant price, and scarce supply of traditional ceramic reinforcements remain challenging. This research countermeasure the challenges by hybridizing the A383 with industrial marble dust (MD) and hexagonal boron nitride (hBN) through the stir-cum-squeeze casting technique. A constant proportion (4 wt%) of MD waste and varying proportions of hBN (1.5, 3, 4.5, and 6 wt%) were used to reinforce A383 alloy to improve its physio-mechanical characteristics. Stir-cum-squeeze casting enables homogenous dispersion of reinforcement particles within the matrix, resulting in improved interfacial bonding. Optimal results were achieved for A383 alloy reinforced with 4 wt% of MD and 6 wt% hBN, ensuring balanced tribo-mechanical characteristics against the as-casted A383. The hardness value increased by 40.8%, while the compression and tensile strength increased by 30.8% and 115.8%, respectively. Non-destructive testing confirms the effective reduction of porosity in the stir-cum-squeeze-cast composites. Moreover, the hybrid composites exhibit improved corrosion resistance by 32.18% after 72 h of testing. Additionally, the hybrid composites demonstrate a wear rate reduction of 54.35%.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"52 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139979828","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}
Pub Date : 2024-02-26DOI: 10.1177/14644207241233947
Henrique Queiroz, Vitor Pastor, Jorge Neto, Daniel Cavalcanti, Mariana D Banea
In recent years, the use of hybrid composites consisting of natural and synthetic fibers has gained increasing attention due to their potential for improved mechanical performance and sustainability. The primary aim of this study was to explore the impact of integrating jute and carbon fiber components into hybrid composites on the enhancement of the materials’ mechanical properties. Jute and carbon bidirectional fabrics were used with a bi-component epoxy matrix in order to fabricate the hybrid composite materials. The carbon bidirectional fabrics were placed on the outer layers, while the jute fabrics were used as the core of the hybrid composites. The core fibers were controlled by the number of layers (5), while the synthetic outer layers were varied (1 and 2, symmetrically and asymmetrically). The composite materials were characterized mechanically via tensile, flexural and impact tests. The results show that both the hybridization technique and the reinforcement symmetry significantly affect the general mechanical properties. In the analysis of tensile properties, a consistent monotonic increase in enhancement tendencies was observed with an increasing fraction of carbon fibers. Conversely, under flexion, a plateau was evident with regard to the hybridization architectural variations, although this behavior was not observed for the flexural modulus, which exhibited a continuous monotonic enhancement relative to the fraction of carbon fibers. Finally, under impact conditions, it was found that symmetry of the synthetic envelope is highly advantageous.
{"title":"Mechanical characterization of jute/carbon hybrid epoxy composites","authors":"Henrique Queiroz, Vitor Pastor, Jorge Neto, Daniel Cavalcanti, Mariana D Banea","doi":"10.1177/14644207241233947","DOIUrl":"https://doi.org/10.1177/14644207241233947","url":null,"abstract":"In recent years, the use of hybrid composites consisting of natural and synthetic fibers has gained increasing attention due to their potential for improved mechanical performance and sustainability. The primary aim of this study was to explore the impact of integrating jute and carbon fiber components into hybrid composites on the enhancement of the materials’ mechanical properties. Jute and carbon bidirectional fabrics were used with a bi-component epoxy matrix in order to fabricate the hybrid composite materials. The carbon bidirectional fabrics were placed on the outer layers, while the jute fabrics were used as the core of the hybrid composites. The core fibers were controlled by the number of layers (5), while the synthetic outer layers were varied (1 and 2, symmetrically and asymmetrically). The composite materials were characterized mechanically via tensile, flexural and impact tests. The results show that both the hybridization technique and the reinforcement symmetry significantly affect the general mechanical properties. In the analysis of tensile properties, a consistent monotonic increase in enhancement tendencies was observed with an increasing fraction of carbon fibers. Conversely, under flexion, a plateau was evident with regard to the hybridization architectural variations, although this behavior was not observed for the flexural modulus, which exhibited a continuous monotonic enhancement relative to the fraction of carbon fibers. Finally, under impact conditions, it was found that symmetry of the synthetic envelope is highly advantageous.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"11 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139979856","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}
Pub Date : 2024-02-24DOI: 10.1177/14644207241232106
L Prakash, KR Balasubramanian, G Sankar, D Santhosh kumar, V Sudharsanam
Local post-weld heat treatment (PWHT) is the only option for heat treating field welded joints. Quite often, the success of local PWHT in alleviating the residual stress and tempering the material within the soak band (SB) is dependent on the ability to achieve the required heat treatment temperature and maintain through-thickness temperature gradient (TTG) within the specified limits at the end of heating cycle, whence soaking begins. Field observations reveal the inadequacy of AWS D 10.10 specified parameters viz. rate of heating (ROH), heat band (HB) and insulation band width in not achieving the required TTG for certain pipe dimensions. Although prior works have attempted to address this issue by widening the HB, the capacity of the heating equipment often pose a limitation. In such cases, reducing ROH is a plausible alternative. With, no such prior studies seen in literature, an exhaustive finite-element analysis simulating the local PWHT on 81, SA106GrC pipe samples (diameter and thickness varied in 9 levels each) was performed, thrice. First as per AWS recommendations, second by halving the code deduced ROH and third by doubling the code deduced HB. The trend of important outcomes (TTG, power source rating and energy consumption) with great significance to the heat treatment industry were also compared and analysed. Two nomograms were developed to serve as a ready reckoner for field heat treater in not only assessing the adequacy of heat treatment parameters but also with possible alternatives in achieving the desired TTG using field-available power source.
{"title":"Correlating pipe dimensions and success of local heat treatment: Developing nomograms to deduce heat treatment parameters","authors":"L Prakash, KR Balasubramanian, G Sankar, D Santhosh kumar, V Sudharsanam","doi":"10.1177/14644207241232106","DOIUrl":"https://doi.org/10.1177/14644207241232106","url":null,"abstract":"Local post-weld heat treatment (PWHT) is the only option for heat treating field welded joints. Quite often, the success of local PWHT in alleviating the residual stress and tempering the material within the soak band (SB) is dependent on the ability to achieve the required heat treatment temperature and maintain through-thickness temperature gradient (TTG) within the specified limits at the end of heating cycle, whence soaking begins. Field observations reveal the inadequacy of AWS D 10.10 specified parameters viz. rate of heating (ROH), heat band (HB) and insulation band width in not achieving the required TTG for certain pipe dimensions. Although prior works have attempted to address this issue by widening the HB, the capacity of the heating equipment often pose a limitation. In such cases, reducing ROH is a plausible alternative. With, no such prior studies seen in literature, an exhaustive finite-element analysis simulating the local PWHT on 81, SA106GrC pipe samples (diameter and thickness varied in 9 levels each) was performed, thrice. First as per AWS recommendations, second by halving the code deduced ROH and third by doubling the code deduced HB. The trend of important outcomes (TTG, power source rating and energy consumption) with great significance to the heat treatment industry were also compared and analysed. Two nomograms were developed to serve as a ready reckoner for field heat treater in not only assessing the adequacy of heat treatment parameters but also with possible alternatives in achieving the desired TTG using field-available power source.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"195 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139948831","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}
Shape memory alloys have made rapid progress in many domains, primarily biomedical (endovascular stents, orthodontic archwires), and engineering (smart actuators, robotics, hydraulic couplings). The selection of a shape memory alloy for the indented application is based on its characteristic phase transformation temperatures. These characteristic temperatures are influenced by myriad parameters, such as composition, microstructure of the alloy, defect density, etc. When an shape memory alloy under an external load is subjected to cyclic operations to perform useful work, for example, actuators, these characteristic temperatures are modified. This study, therefore, aims to understand the influence of external loading on the shape memory characteristics of a Ni50Ti45Cu5 (at.%) alloy. A wire of 1.43 mm diameter and length of 100 mm was subjected to heating and cooling between its phase transformation temperatures in a cyclic manner under constant stress (of up to 60 MPa). The maximum recovery strain, actuation/retraction rate, and the stress influence coefficient were determined and compared with those of the other Ni-Ti and Cu-based shape memory alloys. The results show that raising the load level causes an increase in the transition temperatures, especially the Ms (martensite start temperature) rather than the other phase transformation temperatures (martensite finish (Mf), austenite start (As), austenite finish (Af)). It also significantly affects the recovery strain and the rate of retraction during forward transformation and the symmetry of operation.
{"title":"Influence of applied stress on shape memory characteristics of Ni50Ti45Cu5 (at.%) alloy subjected to thermomechanical cycling","authors":"Swaminathan Ganesan, Sampath Vedamanickam, Adarsh Sorekunte Huchappa","doi":"10.1177/14644207241232900","DOIUrl":"https://doi.org/10.1177/14644207241232900","url":null,"abstract":"Shape memory alloys have made rapid progress in many domains, primarily biomedical (endovascular stents, orthodontic archwires), and engineering (smart actuators, robotics, hydraulic couplings). The selection of a shape memory alloy for the indented application is based on its characteristic phase transformation temperatures. These characteristic temperatures are influenced by myriad parameters, such as composition, microstructure of the alloy, defect density, etc. When an shape memory alloy under an external load is subjected to cyclic operations to perform useful work, for example, actuators, these characteristic temperatures are modified. This study, therefore, aims to understand the influence of external loading on the shape memory characteristics of a Ni<jats:sub>50</jats:sub>Ti<jats:sub>45</jats:sub>Cu<jats:sub>5</jats:sub> (at.%) alloy. A wire of 1.43 mm diameter and length of 100 mm was subjected to heating and cooling between its phase transformation temperatures in a cyclic manner under constant stress (of up to 60 MPa). The maximum recovery strain, actuation/retraction rate, and the stress influence coefficient were determined and compared with those of the other Ni-Ti and Cu-based shape memory alloys. The results show that raising the load level causes an increase in the transition temperatures, especially the M<jats:sub>s</jats:sub> (martensite start temperature) rather than the other phase transformation temperatures (martensite finish (M<jats:sub>f</jats:sub>), austenite start (A<jats:sub>s</jats:sub>), austenite finish (A<jats:sub>f</jats:sub>)). It also significantly affects the recovery strain and the rate of retraction during forward transformation and the symmetry of operation.","PeriodicalId":20630,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications","volume":"2015 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139948828","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}
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：