This study proposes a novel human-inspired metaheuristic search algorithm called marathon runner algorithm. This method mimics competitive behaviors observed in real marathon runners through mathematical modeling. Unlike classical elitist algorithms that prioritize position of the best agent, the marathon runner algorithm introduces a novel concept called vision point. This point considers the quality of the entire population, not just the leader. By guiding the population towards vision point, the risk of getting trapped in local optima is reduced. A two-part evaluation was conducted to thoroughly assess the search capabilities of the marathon runner algorithm. First, it is tested against a set of unconstrained benchmark mathematical functions and the algorithm’s quantitative attributes, such as complexity, accuracy, stability, diversity, sensitivity, and convergence rate are analyzed. Subsequently, the algorithm was applied to mechanical and structural optimization problems with both continuous and discrete variables. This application demonstrated the effectiveness of the algorithm in solving practical engineering challenges with constraints. The outcomes are compared with those obtained by six other well-established techniques. The obtained results indicate that the marathon runner algorithm yields promising and competitive solutions for both mathematical, mechanical, and structural problems.
{"title":"Marathon runner algorithm: theory and application in mathematical, mechanical and structural optimization problems","authors":"Ali Mortazavi","doi":"10.1515/mt-2023-0091","DOIUrl":"https://doi.org/10.1515/mt-2023-0091","url":null,"abstract":"\u0000 This study proposes a novel human-inspired metaheuristic search algorithm called marathon runner algorithm. This method mimics competitive behaviors observed in real marathon runners through mathematical modeling. Unlike classical elitist algorithms that prioritize position of the best agent, the marathon runner algorithm introduces a novel concept called vision point. This point considers the quality of the entire population, not just the leader. By guiding the population towards vision point, the risk of getting trapped in local optima is reduced. A two-part evaluation was conducted to thoroughly assess the search capabilities of the marathon runner algorithm. First, it is tested against a set of unconstrained benchmark mathematical functions and the algorithm’s quantitative attributes, such as complexity, accuracy, stability, diversity, sensitivity, and convergence rate are analyzed. Subsequently, the algorithm was applied to mechanical and structural optimization problems with both continuous and discrete variables. This application demonstrated the effectiveness of the algorithm in solving practical engineering challenges with constraints. The outcomes are compared with those obtained by six other well-established techniques. The obtained results indicate that the marathon runner algorithm yields promising and competitive solutions for both mathematical, mechanical, and structural problems.","PeriodicalId":18231,"journal":{"name":"Materials Testing","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141104002","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}
The rapid depletion of natural resources and the increase of environmental problems due to production-related waste necessitate sustainable waste management. In particular, reintroducing by-products and waste generated by agricultural activities into the economy is critical to reduce environmental pollution, solve the storage problem, and promote sustainability. Agricultural wastes such as fiber, husks, cobs, stalks, straw, dust, and particles are recyclable and can be innovatively reused in various sectors. One of the innovative fields where sustainable agricultural waste management can be implemented is the development of biocomposites. One of the most important steps in the production of biocomposites reinforced with agricultural waste is processing the waste biomass and making it usable as a reinforcing element. This study investigated the production of powder reinforcements for biocomposite material from the biomass of walnut shells using a ring mill. The walnut shells, mechanically reduced in size, were first dried at 100 °C for 3 h and ground at four different grinding times (10, 20, 30, and 40 min). Afterward, the waste walnut shell powders were subjected to sieve analysis and precise weight measurements. Then, the waste walnut shell powders, which were dried at 100 °C for 3 h and ground for 40 min, were subjected to a second drying process at 100 °C (60, 180, and 300 min) and ground again for 40 min. Then, the resulting waste walnut shell powders were subjected to sieve analysis, precision weight measurements, and microscopic, and SEM analyses to determine the characterization of the powders.
自然资源的迅速枯竭和与生产有关的废物所导致的环境问题的增加，使得可持续废物管理成为必要。特别是，将农业活动产生的副产品和废物重新引入经济领域，对于减少环境污染、解决储存问题和促进可持续发展至关重要。农业废弃物，如纤维、谷壳、棒子、秸秆、稻草、灰尘和颗粒等，都是可回收的，可以创新性地重新用于各个领域。可持续农业废物管理的创新领域之一是开发生物复合材料。利用农业废弃物生产增强生物复合材料的最重要步骤之一是加工废弃生物质，使其成为可利用的增强元素。本研究调查了使用环形磨粉机从核桃壳生物质中生产生物复合材料粉末增强材料的情况。核桃壳经机械粉碎后，首先在 100 °C 下干燥 3 小时，然后以四种不同的研磨时间（10、20、30 和 40 分钟）进行研磨。然后，对废弃核桃壳粉末进行筛分分析和精确的重量测量。然后，在 100 °C 下干燥 3 小时并研磨 40 分钟的废核桃壳粉末在 100 °C 下进行第二次干燥处理（60、180 和 300 分钟），并再次研磨 40 分钟。然后，对所得废核桃壳粉末进行筛分分析、精密重量测量、显微镜和扫描电镜分析，以确定粉末的特性。
{"title":"Production and characterization of waste walnut shell powder that can be used as a sustainable eco-friendly reinforcement in biocomposites","authors":"B. Çevik, Yücel Avşar","doi":"10.1515/mt-2024-0018","DOIUrl":"https://doi.org/10.1515/mt-2024-0018","url":null,"abstract":"\u0000 The rapid depletion of natural resources and the increase of environmental problems due to production-related waste necessitate sustainable waste management. In particular, reintroducing by-products and waste generated by agricultural activities into the economy is critical to reduce environmental pollution, solve the storage problem, and promote sustainability. Agricultural wastes such as fiber, husks, cobs, stalks, straw, dust, and particles are recyclable and can be innovatively reused in various sectors. One of the innovative fields where sustainable agricultural waste management can be implemented is the development of biocomposites. One of the most important steps in the production of biocomposites reinforced with agricultural waste is processing the waste biomass and making it usable as a reinforcing element. This study investigated the production of powder reinforcements for biocomposite material from the biomass of walnut shells using a ring mill. The walnut shells, mechanically reduced in size, were first dried at 100 °C for 3 h and ground at four different grinding times (10, 20, 30, and 40 min). Afterward, the waste walnut shell powders were subjected to sieve analysis and precise weight measurements. Then, the waste walnut shell powders, which were dried at 100 °C for 3 h and ground for 40 min, were subjected to a second drying process at 100 °C (60, 180, and 300 min) and ground again for 40 min. Then, the resulting waste walnut shell powders were subjected to sieve analysis, precision weight measurements, and microscopic, and SEM analyses to determine the characterization of the powders.","PeriodicalId":18231,"journal":{"name":"Materials Testing","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141111288","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}
TIG welding is an important joining technique for fabricating quality structural components with industrial capability. Dissimilar alloy plates were combined using double-sided tungsten inert gas (TIG) welding. Microstructure evaluation of joints were anayzed by using scanning electron microscopy, optical microscope, energy dispersion spectrometry, elemental mapping, electron back scatter diffraction. DSAW technique increased joint penetration and reduced distortion of joints. In the weld metal zone, austenite, delta ferrite and lath martensite were dominant. The weld pool had high density of Cr7C3 and Fe3C phases and low density of CrFe7C0.45, FeNi, martensite, and Fe3Ni2 phases.
{"title":"Weld interface metallurgy of dissimilar alloys welded by TIG technique","authors":"T. Teker, Ahmet Günes","doi":"10.1515/mt-2024-0022","DOIUrl":"https://doi.org/10.1515/mt-2024-0022","url":null,"abstract":"\u0000 TIG welding is an important joining technique for fabricating quality structural components with industrial capability. Dissimilar alloy plates were combined using double-sided tungsten inert gas (TIG) welding. Microstructure evaluation of joints were anayzed by using scanning electron microscopy, optical microscope, energy dispersion spectrometry, elemental mapping, electron back scatter diffraction. DSAW technique increased joint penetration and reduced distortion of joints. In the weld metal zone, austenite, delta ferrite and lath martensite were dominant. The weld pool had high density of Cr7C3 and Fe3C phases and low density of CrFe7C0.45, FeNi, martensite, and Fe3Ni2 phases.","PeriodicalId":18231,"journal":{"name":"Materials Testing","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141110247","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 study, experimental analyses and numerical simulations of polyethylene terephthalate glycol (PETG) pedal pins with optimum production parameters are performed concerning mechanical properties. The aim of this study is twofold: first, the effect of the three-dimensional (3D) manufacturing process, which has a significant impact on the mechanical properties of the 3D-printed part, is realized experimentally. Second, the mechanical behavior of the 3D-printed clutch pedal pin is evaluated using both numerical simulation and experimental tests, which is an important application for lightweight vehicles. It is observed that the determined production parameters can significantly improve the mechanical behavior of the materials and the pin of the vehicle pedal mechanism can be replaced with a lighter structure. Thus, the results obtained in this paper are of the utmost importance for the manufacturer to choose the optimum manufacturing parameters of three-dimensional printed materials and their application to vehicle pedals and other possible parts.
本研究对具有最佳生产参数的聚对苯二甲酸乙二酯（PETG）踏板栓的机械性能进行了实验分析和数值模拟。本研究的目的有两个：首先，通过实验了解三维（3D）制造工艺对 3D 打印部件机械性能的重要影响。其次，利用数值模拟和实验测试评估了三维打印离合器踏板销的机械性能，这对于轻量化汽车来说是一项重要应用。结果表明，确定的生产参数可以显著改善材料的机械性能，车辆踏板机构的销可以用更轻的结构替代。因此，本文获得的结果对于制造商选择三维印刷材料的最佳生产参数以及将其应用于汽车踏板和其他可能的部件具有极其重要的意义。
{"title":"Experimental testing and numerical simulations of 3D-printed PETG pins used for vehicle pedals","authors":"Muhammed Ali Koksal, Ahmet Yildiz","doi":"10.1515/mt-2024-0007","DOIUrl":"https://doi.org/10.1515/mt-2024-0007","url":null,"abstract":"\u0000 In this study, experimental analyses and numerical simulations of polyethylene terephthalate glycol (PETG) pedal pins with optimum production parameters are performed concerning mechanical properties. The aim of this study is twofold: first, the effect of the three-dimensional (3D) manufacturing process, which has a significant impact on the mechanical properties of the 3D-printed part, is realized experimentally. Second, the mechanical behavior of the 3D-printed clutch pedal pin is evaluated using both numerical simulation and experimental tests, which is an important application for lightweight vehicles. It is observed that the determined production parameters can significantly improve the mechanical behavior of the materials and the pin of the vehicle pedal mechanism can be replaced with a lighter structure. Thus, the results obtained in this paper are of the utmost importance for the manufacturer to choose the optimum manufacturing parameters of three-dimensional printed materials and their application to vehicle pedals and other possible parts.","PeriodicalId":18231,"journal":{"name":"Materials Testing","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141111713","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 study, pure and hBN-doped ZnO nanoparticles were synthesized by sol–gel method. ZnO–hBN nanoparticles were mixed with pure aluminum powders and samples were prepared using powder metallurgy processing parameters. It was observed that Al, ZnO, and hBN nanocomposite particles formed homogeneously. With the addition of ZnO–hBN, significant changes occurred in hardness, wear, and friction coefficient values compared to pure Al samples. The highest hardness value in the samples is mesh. It was obtained as 105 HB in 10 wt.% hBN added sample. In the wear tests, it is seen that the wear resistance is seven times higher in the 1 wt.% hBN added sample compared to the pure Al sample, while the friction coefficient decreases with the increase of the hBN additive.
{"title":"Microstructure and tribological properties of aluminum matrix composites reinforced with ZnO–hBN nanocomposite particles","authors":"Cevher Kürşat Macit, Muhammet Gokhan Albayrak, Burak Tanyeri, Turan Gurgenc, Cihan Ozel","doi":"10.1515/mt-2023-0259","DOIUrl":"https://doi.org/10.1515/mt-2023-0259","url":null,"abstract":"\u0000 In this study, pure and hBN-doped ZnO nanoparticles were synthesized by sol–gel method. ZnO–hBN nanoparticles were mixed with pure aluminum powders and samples were prepared using powder metallurgy processing parameters. It was observed that Al, ZnO, and hBN nanocomposite particles formed homogeneously. With the addition of ZnO–hBN, significant changes occurred in hardness, wear, and friction coefficient values compared to pure Al samples. The highest hardness value in the samples is mesh. It was obtained as 105 HB in 10 wt.% hBN added sample. In the wear tests, it is seen that the wear resistance is seven times higher in the 1 wt.% hBN added sample compared to the pure Al sample, while the friction coefficient decreases with the increase of the hBN additive.","PeriodicalId":18231,"journal":{"name":"Materials Testing","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140961845","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}
Eight type of commercial cold work tool steels were heat treated to achieve the equal hardness of 650 HV. Heat-treated samples were investigated by optical and scanning electron microscopy (SEM), microhardness, and X-ray diffraction (XRD) to identify microstructural features and phases. The samples were examined in three distinct wear modes: adhesion, two-body wear using pin wear on SiC, and recycling plastic cutting machine, respectively. The wear surfaces of samples were analyzed by 3D scanning technology. The microstructure of steels determined their wear characteristics. For low sliding and higher cutting speeds, the order of adhesive wear performance of the steels was reversed due to the stress occurring in the cutting line. The wear rate of all samples was commensurate with load. In the recycling plastic cutting process, the sample with the minimum and homogeneously dispersed carbides exhibited the best wear performance. Tempering the S3 sample prevented crack formation and improved fracture toughness.
对八种商用冷作工具钢进行了热处理，使其硬度达到 650 HV。通过光学和扫描电子显微镜 (SEM)、显微硬度和 X 射线衍射 (XRD) 对热处理样品进行了研究，以确定微结构特征和相。分别在三种不同的磨损模式下对样品进行了检测：粘着磨损、在 SiC 上使用针磨损的双体磨损以及回收塑料切割机。通过三维扫描技术对样品的磨损表面进行了分析。钢的微观结构决定了其磨损特性。在低滑动和较高的切割速度下，由于切割线中产生的应力，钢的粘合磨损性能顺序发生了逆转。所有样品的磨损率都与载荷成正比。在循环塑性切削过程中，碳化物最少且分散均匀的试样磨损性能最好。对 S3 样品进行回火处理可防止裂纹形成并提高断裂韧性。
{"title":"Wear characteristics of cold tool steels for recycling plastic preprocessing","authors":"I. Dalmis, S. Yılmaz, T. Teker","doi":"10.1515/mt-2024-0014","DOIUrl":"https://doi.org/10.1515/mt-2024-0014","url":null,"abstract":"\u0000 Eight type of commercial cold work tool steels were heat treated to achieve the equal hardness of 650 HV. Heat-treated samples were investigated by optical and scanning electron microscopy (SEM), microhardness, and X-ray diffraction (XRD) to identify microstructural features and phases. The samples were examined in three distinct wear modes: adhesion, two-body wear using pin wear on SiC, and recycling plastic cutting machine, respectively. The wear surfaces of samples were analyzed by 3D scanning technology. The microstructure of steels determined their wear characteristics. For low sliding and higher cutting speeds, the order of adhesive wear performance of the steels was reversed due to the stress occurring in the cutting line. The wear rate of all samples was commensurate with load. In the recycling plastic cutting process, the sample with the minimum and homogeneously dispersed carbides exhibited the best wear performance. Tempering the S3 sample prevented crack formation and improved fracture toughness.","PeriodicalId":18231,"journal":{"name":"Materials Testing","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140961846","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}
Additive manufacturing enables the fabrication of versatile and cost-effective metallic-alloy components from a digital data model. This study explores the prospects of selective laser melting (SLM), an additive manufacturing technique, for fabricating Ti6Al4V alloy components from Ti6Al4V alloy powders. Selective laser melting parameters, such as laser power, scanning speed, powder thickness, hatching space, and scanning strategy, are carefully selected through a series of experiments. The metallurgical characteristics (microstructure, grain orientation, and phase composition), microhardness, and creep performance of the as-fabricated specimens are tested and analyzed. The kinetics of phase transformation and rupture mechanism are determined using advanced instrumental characterization tools, such as field emission scanning electron microscope, energy dispersive X-ray spectroscope, X-ray diffractometer, and transmission electron microscope.
快速成型制造技术可以根据数字数据模型制造出多功能、高性价比的金属合金部件。本研究探讨了选择性激光熔化（SLM）这一快速成型制造技术在利用 Ti6Al4V 合金粉末制造 Ti6Al4V 合金部件方面的应用前景。通过一系列实验，精心选择了选择性激光熔化参数，如激光功率、扫描速度、粉末厚度、孵化空间和扫描策略。测试和分析了制备试样的冶金特性（显微结构、晶粒取向和相组成）、显微硬度和蠕变性能。利用先进的仪器表征工具，如场发射扫描电子显微镜、能量色散 X 射线光谱仪、X 射线衍射仪和透射电子显微镜，确定了相变动力学和断裂机制。
{"title":"Low-temperature creep performance of additive manufactured Ti–6Al–4V","authors":"Dudala Vamsi Deepak, Abhinav Chavali, Palukuri Amruth, Murari Harshavardhan, Vaira Vignesh Ramalingam, Govindaraju Myilsamy","doi":"10.1515/mt-2023-0166","DOIUrl":"https://doi.org/10.1515/mt-2023-0166","url":null,"abstract":"\u0000 Additive manufacturing enables the fabrication of versatile and cost-effective metallic-alloy components from a digital data model. This study explores the prospects of selective laser melting (SLM), an additive manufacturing technique, for fabricating Ti6Al4V alloy components from Ti6Al4V alloy powders. Selective laser melting parameters, such as laser power, scanning speed, powder thickness, hatching space, and scanning strategy, are carefully selected through a series of experiments. The metallurgical characteristics (microstructure, grain orientation, and phase composition), microhardness, and creep performance of the as-fabricated specimens are tested and analyzed. The kinetics of phase transformation and rupture mechanism are determined using advanced instrumental characterization tools, such as field emission scanning electron microscope, energy dispersive X-ray spectroscope, X-ray diffractometer, and transmission electron microscope.","PeriodicalId":18231,"journal":{"name":"Materials Testing","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140976957","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}
An AlCoCrFeNi high-entropy alloy coating containing 20 % mass fraction of TiC was prepared using the laser cladding method. The effect of heat treatment on the coating’s microstructure was analyzed through X-ray diffraction (XRD), scanning electron microscopy (SEM), electron backscattered diffraction (EBSD), and transmission electron microscopy (TEM). It was observed that following high-temperature heat treatment, the phase transition of AlCoCrFeNi–20%TiC shifted from BCC to FCC at 750 °C. Through microhardness and wear resistance tests, the increased diffusion of carbon post-heat treatment led to a higher precipitation of TiC-reinforced phases, resulting in exceptional wear resistance with a notable 128.3 % enhancement.
{"title":"Wear resistance optimized by heat treatment of an in-situ TiC strengthened AlCoCrFeNi laser cladding coating","authors":"Mingxin Wang, Yutao Li, Tounan Jin, Hanguang Fu","doi":"10.1515/mt-2023-0412","DOIUrl":"https://doi.org/10.1515/mt-2023-0412","url":null,"abstract":"\u0000 An AlCoCrFeNi high-entropy alloy coating containing 20 % mass fraction of TiC was prepared using the laser cladding method. The effect of heat treatment on the coating’s microstructure was analyzed through X-ray diffraction (XRD), scanning electron microscopy (SEM), electron backscattered diffraction (EBSD), and transmission electron microscopy (TEM). It was observed that following high-temperature heat treatment, the phase transition of AlCoCrFeNi–20%TiC shifted from BCC to FCC at 750 °C. Through microhardness and wear resistance tests, the increased diffusion of carbon post-heat treatment led to a higher precipitation of TiC-reinforced phases, resulting in exceptional wear resistance with a notable 128.3 % enhancement.","PeriodicalId":18231,"journal":{"name":"Materials Testing","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140974206","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, the development of MoBeMeG, a modular device for bending-corrosion-fatigue investigations and variable specimen geometry in corrosive media with galvanic isolation between the test chamber and the test system, is presented. The main application is the investigation of hybrid laminates with high potential for galvanic corrosion, e.g., aluminum ∪ carbon fiber–reinforced plastics, focusing on the description of failure mechanisms and failure evolution at the interface under the influence of bending-corrosion-fatigue loading. The anvil distances are adjustable for the application of varying specimen geometries while retaining the full functionality of the test chamber and securing a full flexible testing possibility without the necessity of new constructions. The test engineering development results in considerable time savings as well as unparalleled efficiency enhancement in terms of bending-corrosion-fatigue performance assessments.
{"title":"Development and validation of a test facility for bending corrosion fatigue of hybrid laminates","authors":"A. Delp, Frank Walther","doi":"10.1515/mt-2024-0034","DOIUrl":"https://doi.org/10.1515/mt-2024-0034","url":null,"abstract":"\u0000 In this article, the development of MoBeMeG, a modular device for bending-corrosion-fatigue investigations and variable specimen geometry in corrosive media with galvanic isolation between the test chamber and the test system, is presented. The main application is the investigation of hybrid laminates with high potential for galvanic corrosion, e.g., aluminum ∪ carbon fiber–reinforced plastics, focusing on the description of failure mechanisms and failure evolution at the interface under the influence of bending-corrosion-fatigue loading. The anvil distances are adjustable for the application of varying specimen geometries while retaining the full functionality of the test chamber and securing a full flexible testing possibility without the necessity of new constructions. The test engineering development results in considerable time savings as well as unparalleled efficiency enhancement in terms of bending-corrosion-fatigue performance assessments.","PeriodicalId":18231,"journal":{"name":"Materials Testing","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140978861","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}
Constant amplitude fatigue tests were conducted on 6061/7075 dissimilar aluminum alloy laser welded lap specimens, as well as weld line cross-section hardness measurements. The fatigue test results show that the specimens exhibit multiple fracture modes that exit near the weld seam. The microhardness data on weld line cross-section from 7075 side to 6061 side display a sharp change and the softening phenomenon is serious. The hardness variation in heat affected zone of laser welding is very shallow, and its hardness is close to that of the base material. It was found that there are slag inclusions and pores in the weld seam when observing the fatigue fracture surface using SEM, and a small amount of secondary cracks were generated. However, stress concentration plays a dominant role in causing specimen fracture under fatigue loading, rather than welding defects. Defective specimens are found to have higher fatigue strength. The fatigue life prediction results obtained by the notch stress method and the hot spot stress method are both conservative and fall within two factor lines. The hot spot stress method has relatively higher accuracy for life prediction. The accuracy of both methods in predicting life is influenced by the location of the fracture.
{"title":"Fatigue life evaluation of laser welded lap joints of dissimilar aluminum alloys","authors":"Xiangyun Liao, Ruijie Wang, Pinglin Zhao","doi":"10.1515/mt-2024-0003","DOIUrl":"https://doi.org/10.1515/mt-2024-0003","url":null,"abstract":"\u0000 Constant amplitude fatigue tests were conducted on 6061/7075 dissimilar aluminum alloy laser welded lap specimens, as well as weld line cross-section hardness measurements. The fatigue test results show that the specimens exhibit multiple fracture modes that exit near the weld seam. The microhardness data on weld line cross-section from 7075 side to 6061 side display a sharp change and the softening phenomenon is serious. The hardness variation in heat affected zone of laser welding is very shallow, and its hardness is close to that of the base material. It was found that there are slag inclusions and pores in the weld seam when observing the fatigue fracture surface using SEM, and a small amount of secondary cracks were generated. However, stress concentration plays a dominant role in causing specimen fracture under fatigue loading, rather than welding defects. Defective specimens are found to have higher fatigue strength. The fatigue life prediction results obtained by the notch stress method and the hot spot stress method are both conservative and fall within two factor lines. The hot spot stress method has relatively higher accuracy for life prediction. The accuracy of both methods in predicting life is influenced by the location of the fracture.","PeriodicalId":18231,"journal":{"name":"Materials Testing","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140979394","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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