Antibiotic overuse has caused a variety of bacterial pathogens to develop new resistance mechanisms. As a result, discovering an appropriate replacement for the standard antibiotics has become an immediate concern. The present work demonstrates a facile, eco-friendly and economical method for the synthesis of hexagonal wurtzite zinc oxide nanoparticles (ω-ZONPs) using the ethanolic extract of triphala. Gas chromatography–mass spectrometry analysis of the triphala extract proved the presence of certain secondary metabolites, which aids in the formation of ω-ZONPs. The influence of annealing temperature on the antibacterial action of as-synthesized ω-ZONPs was studied for three different annealing temperatures. X-ray diffraction, dynamic light scattering, field emission electron microscopy and energy dispersive X-ray spectroscopy analyses were used to examine the impact of annealing temperature on the structure, particle size and morphology of ω-ZONPs. Fourier transform infrared spectra revealed the change in intensity of the characteristic peaks in ω-ZONPs with different annealing temperatures. From UV–Visible diffuse reflectance spectroscopy, variation in the band gap of ω-ZONPs with increasing annealing temperature was detected. Kirby Bauer disc diffusion was adopted to examine the antibacterial potential of ω-ZONPs against bacterial strains such as Staphylococcus aureus, Enterococcus faecium, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The ω-ZONPs annealed at 200 °C inhibited the growth of three bacterial pathogens, E. coli, B. subtilis and P. aeruginosa and exhibited effective antibacterial activity in comparison with ω-ZONPs annealed at relatively high temperatures. Thus, the antibacterial potential of ω-ZONPs could be further explored as disease controlling agents and such prototypes could be made available for commercial mass production.
抗生素的过度使用导致各种细菌病原体产生了新的抗药性机制。因此，发现标准抗生素的适当替代品已成为当务之急。本研究展示了一种利用三叶草乙醇提取物合成六方菱形氧化锌纳米颗粒（ω-ZONPs）的简便、环保和经济的方法。对三叶草提取物的气相色谱-质谱分析证明，其中存在某些次生代谢物，有助于ω-ZONPs 的形成。在三种不同的退火温度下，研究了退火温度对合成的 ω-ZONPs 抗菌作用的影响。利用 X 射线衍射、动态光散射、场发射电子显微镜和能量色散 X 射线光谱分析了退火温度对 ω-ZONPs 结构、粒度和形态的影响。傅立叶变换红外光谱显示了不同退火温度下 ω-ZONPs 特征峰强度的变化。紫外-可见漫反射光谱显示，ω-ZONPs 的带隙随退火温度的升高而变化。采用柯比鲍尔盘扩散法检测了ω-ZONPs 对金黄色葡萄球菌、粪肠球菌、枯草杆菌、大肠杆菌和铜绿假单胞菌等细菌菌株的抗菌潜力。与在相对较高温度下退火的ω-ZONPs 相比，在 200 °C 下退火的ω-ZONPs 能抑制大肠杆菌、枯草杆菌和绿脓杆菌这三种细菌病原体的生长，并表现出有效的抗菌活性。因此，ω-ZONPs 作为疾病控制剂的抗菌潜力有待进一步探索，其原型可用于商业化大规模生产。
{"title":"Influence of annealing temperature on the structure, morphology, optical property and antibacterial response of phytochemicals-assisted synthesized zinc oxide nanoparticles","authors":"Buvana Sampath, Julie Charles","doi":"10.1515/ijmr-2023-0243","DOIUrl":"https://doi.org/10.1515/ijmr-2023-0243","url":null,"abstract":"\u0000 Antibiotic overuse has caused a variety of bacterial pathogens to develop new resistance mechanisms. As a result, discovering an appropriate replacement for the standard antibiotics has become an immediate concern. The present work demonstrates a facile, eco-friendly and economical method for the synthesis of hexagonal wurtzite zinc oxide nanoparticles (ω-ZONPs) using the ethanolic extract of triphala. Gas chromatography–mass spectrometry analysis of the triphala extract proved the presence of certain secondary metabolites, which aids in the formation of ω-ZONPs. The influence of annealing temperature on the antibacterial action of as-synthesized ω-ZONPs was studied for three different annealing temperatures. X-ray diffraction, dynamic light scattering, field emission electron microscopy and energy dispersive X-ray spectroscopy analyses were used to examine the impact of annealing temperature on the structure, particle size and morphology of ω-ZONPs. Fourier transform infrared spectra revealed the change in intensity of the characteristic peaks in ω-ZONPs with different annealing temperatures. From UV–Visible diffuse reflectance spectroscopy, variation in the band gap of ω-ZONPs with increasing annealing temperature was detected. Kirby Bauer disc diffusion was adopted to examine the antibacterial potential of ω-ZONPs against bacterial strains such as Staphylococcus aureus, Enterococcus faecium, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The ω-ZONPs annealed at 200 °C inhibited the growth of three bacterial pathogens, E. coli, B. subtilis and P. aeruginosa and exhibited effective antibacterial activity in comparison with ω-ZONPs annealed at relatively high temperatures. Thus, the antibacterial potential of ω-ZONPs could be further explored as disease controlling agents and such prototypes could be made available for commercial mass production.","PeriodicalId":510356,"journal":{"name":"International Journal of Materials Research","volume":"31 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141801504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We have examined the behavior of CoFe2−x Al x O4 (x = 1.0 and 1.2) ferrite close to the transition from ferromagnetic to paramagnetic phases (T C). The findings indicate that at a temperature of T C = 314 K (x = 1.0) and T C = 224 K (x = 1.2), there is a second order magnetic phase transition. We used various methods, including modified Arrott plot, Kouvel–Fisher method, and critical isotherm analysis, to determine the critical exponents which were found to be similar to those expected for the Tricritical Mean-field model (β = 0.288, γ = 1.057, and δ = 4.665) for the x = 1.0 sample. The critical exponents for the x = 1.2 sample (β = 0.771, γ = 1.081, and δ = 2.403) belonged to a different universality class. These results suggest that the replacement of Fe ions with non-magnetic Al ions decreases the Co–Fe, Fe–Fe, Co–Co interaction sites in the CoFe2O4 spinel ferrite, increasing magnetic disorder.
我们研究了 CoFe2-x Al x O4（x = 1.0 和 1.2）铁氧体在从铁磁相过渡到顺磁相 (T C) 附近的行为。研究结果表明，在 T C = 314 K (x = 1.0) 和 T C = 224 K (x = 1.2) 的温度下，存在二阶磁性相变。我们使用各种方法，包括改良阿罗特图、库维尔-费舍法和临界等温线分析，确定了 x = 1.0 样品的临界指数，发现这些指数与三临界平均场模型的预期指数（β = 0.288、γ = 1.057 和 δ = 4.665）相似。x = 1.2 样本的临界指数（β = 0.771、γ = 1.081 和 δ = 2.403）属于不同的普遍性类别。这些结果表明，用非磁性 Al 离子取代 Fe 离子会减少 CoFe2O4 尖晶石铁氧体中的 Co-Fe、Fe-Fe、Co-Co 相互作用位点，从而增加磁性无序性。
{"title":"Study on the magnetic properties and critical behavior of CoFe2−x\u0000 Al\u0000 x\u0000 O4 (x = 1.0 and 1.2) spinel ferrite","authors":"Zonghao Song, Ruiyang Cao, C. Ruan, Xian Zhang, Shou-Yang Wang, Meiling Wang, Yongqing Ma, Ganhong Zheng","doi":"10.1515/ijmr-2023-0330","DOIUrl":"https://doi.org/10.1515/ijmr-2023-0330","url":null,"abstract":"\u0000 We have examined the behavior of CoFe2−x\u0000 Al\u0000 x\u0000 O4 (x = 1.0 and 1.2) ferrite close to the transition from ferromagnetic to paramagnetic phases (T\u0000 C). The findings indicate that at a temperature of T\u0000 C = 314 K (x = 1.0) and T\u0000 C = 224 K (x = 1.2), there is a second order magnetic phase transition. We used various methods, including modified Arrott plot, Kouvel–Fisher method, and critical isotherm analysis, to determine the critical exponents which were found to be similar to those expected for the Tricritical Mean-field model (β = 0.288, γ = 1.057, and δ = 4.665) for the x = 1.0 sample. The critical exponents for the x = 1.2 sample (β = 0.771, γ = 1.081, and δ = 2.403) belonged to a different universality class. These results suggest that the replacement of Fe ions with non-magnetic Al ions decreases the Co–Fe, Fe–Fe, Co–Co interaction sites in the CoFe2O4 spinel ferrite, increasing magnetic disorder.","PeriodicalId":510356,"journal":{"name":"International Journal of Materials Research","volume":"37 20","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141805976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper reports the photoluminescence studies of pure polycrystalline nano-sized gadolinium gallium garnet (Gd3Ga5O12, GGG) powders synthesized by the method of co-precipitation using ammonium hydrogen carbonate (NH4HCO3, AHC) as the precipitant. The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared, ultraviolet, visible, near-infrared (UV–Vis–NIR) spectroscopy and photoluminescence studies. The X-ray diffraction analysis confirms the formation of cubic structure of gadolinium gallium garnet (Gd3Ga5O12). The average particle sizes are found to be in the range of approximately 19 nm–88 nm, for different calcining temperatures. The formation of gadolinium gallium garnet is also confirmed by Fourier transform infrared studies. Scanning electron microscopy image measurement confirms the formation of nanosized particles. The photoluminescence studies of the pure gadolinium gallium garnet sample shows emission peaks around at 441 nm for an excitation wavelength of 350 nm for the sample calcined at 1,100 °C.
本文报道了以碳酸氢铵（NH4HCO3，AHC）为沉淀剂，采用共沉淀法合成的纯多晶纳米级钆镓石榴石（Gd3Ga5O12，GGG）粉末的光致发光研究。制备的样品通过 X 射线衍射、扫描电子显微镜、傅立叶变换红外、紫外、可见光、近红外（UV-Vis-NIR）光谱和光致发光研究进行了表征。X 射线衍射分析证实了钆镓石榴石（Gd3Ga5O12）立方结构的形成。在不同的煅烧温度下，平均粒径大约在 19 nm-88 nm 之间。傅立叶变换红外研究也证实了钆镓石榴石的形成。扫描电子显微镜图像测量证实了纳米级颗粒的形成。对纯钆镓石榴石样品进行的光致发光研究表明，在 1,100 °C 煅烧的样品中，激发波长为 350 nm 时，发射峰在 441 nm 附近。
{"title":"Wet-chemical synthesis and luminescence studies of nano-crystalline gadolinium gallium garnet","authors":"P. P. Pal, Soumyajit Sarkar","doi":"10.1515/ijmr-2023-0371","DOIUrl":"https://doi.org/10.1515/ijmr-2023-0371","url":null,"abstract":"\u0000 This paper reports the photoluminescence studies of pure polycrystalline nano-sized gadolinium gallium garnet (Gd3Ga5O12, GGG) powders synthesized by the method of co-precipitation using ammonium hydrogen carbonate (NH4HCO3, AHC) as the precipitant. The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared, ultraviolet, visible, near-infrared (UV–Vis–NIR) spectroscopy and photoluminescence studies. The X-ray diffraction analysis confirms the formation of cubic structure of gadolinium gallium garnet (Gd3Ga5O12). The average particle sizes are found to be in the range of approximately 19 nm–88 nm, for different calcining temperatures. The formation of gadolinium gallium garnet is also confirmed by Fourier transform infrared studies. Scanning electron microscopy image measurement confirms the formation of nanosized particles. The photoluminescence studies of the pure gadolinium gallium garnet sample shows emission peaks around at 441 nm for an excitation wavelength of 350 nm for the sample calcined at 1,100 °C.","PeriodicalId":510356,"journal":{"name":"International Journal of Materials Research","volume":"42 14","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141809739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The micro-arc oxidation of TC4 titanium alloy was carried out by adding LuCl3. The effect of LuCl3 addition on the properties of the micro-arc oxidized coatings, and the rate of weight loss by erosion under simulated oil field conditions, were analysed. The results show that the increase of oxidation voltage after the addition of LuCl3 makes the surface structure of the coatings denser. The coating is mainly composed of Rutile TiO2, Anatase TiO2, and a small amount of Lu2O3 phase. The kinetic potential polarization curves showed that the addition of LuCl3 can increase the corrosion potential and decrease the corrosion current density of TC4 titanium alloy, and at the same time reduce the rate of erosion weight loss of micro-arc oxidized coatings under simulated oilfield conditions. The overall performance of the coatings is best when the concentration of LuCl3 is 0.3 g L−1.
{"title":"Study on the effect of LuCl3 doping on the characteristics of titanium alloy micro-arc oxidation coatings","authors":"Xiangjie Wang, Ping Wang, Yanfei Duan, Xu Luo, Youping Zheng","doi":"10.1515/ijmr-2024-0049","DOIUrl":"https://doi.org/10.1515/ijmr-2024-0049","url":null,"abstract":"\u0000 The micro-arc oxidation of TC4 titanium alloy was carried out by adding LuCl3. The effect of LuCl3 addition on the properties of the micro-arc oxidized coatings, and the rate of weight loss by erosion under simulated oil field conditions, were analysed. The results show that the increase of oxidation voltage after the addition of LuCl3 makes the surface structure of the coatings denser. The coating is mainly composed of Rutile TiO2, Anatase TiO2, and a small amount of Lu2O3 phase. The kinetic potential polarization curves showed that the addition of LuCl3 can increase the corrosion potential and decrease the corrosion current density of TC4 titanium alloy, and at the same time reduce the rate of erosion weight loss of micro-arc oxidized coatings under simulated oilfield conditions. The overall performance of the coatings is best when the concentration of LuCl3 is 0.3 g L−1.","PeriodicalId":510356,"journal":{"name":"International Journal of Materials Research","volume":"115 49","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141822243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Noor Haider Abdul Ali Al-Shawi, Zh. Ebrahiminejad, Somayeh Asgary
In this research, a three-component composite was synthesized by using carbon nanotube as the background phase. Iron oxide phase with high magnetization and low coercivity (with particle size of 200 nm) has been coated on the carbon nanotubes. Then, the silver nanoparticles were coated on a conductive and magnetized substrate by an ultrasonic method. Semiconductor photocatalys is a favorable route for the degradation of organic pollutants. Ultraviolet–visible spectrophotometry has been used to investigate the photocatalytic properties of synthesized nanocomposite and control of their dye degradation on methyl blue, methyl orange and methyl red. The obtained nanocomposite is easily collected due to its magnetic property and does not pose a risk to environmental waters. The dye degradation degree has been compared for the produced nanocomposite. The experimental results confirmed that methyl red shows the greatest amount of degradation within 1 h, which was about 90 %, methyl orange shows about 80 %, and methyl blue shows the lowest degradation, around 60 %.
{"title":"Synthesis of carbon nanotube–iron oxide and silver nanocomposites as photocatalyst in removing carcinogenic aromatic dyes","authors":"Noor Haider Abdul Ali Al-Shawi, Zh. Ebrahiminejad, Somayeh Asgary","doi":"10.1515/ijmr-2023-0263","DOIUrl":"https://doi.org/10.1515/ijmr-2023-0263","url":null,"abstract":"\u0000 In this research, a three-component composite was synthesized by using carbon nanotube as the background phase. Iron oxide phase with high magnetization and low coercivity (with particle size of 200 nm) has been coated on the carbon nanotubes. Then, the silver nanoparticles were coated on a conductive and magnetized substrate by an ultrasonic method. Semiconductor photocatalys is a favorable route for the degradation of organic pollutants. Ultraviolet–visible spectrophotometry has been used to investigate the photocatalytic properties of synthesized nanocomposite and control of their dye degradation on methyl blue, methyl orange and methyl red. The obtained nanocomposite is easily collected due to its magnetic property and does not pose a risk to environmental waters. The dye degradation degree has been compared for the produced nanocomposite. The experimental results confirmed that methyl red shows the greatest amount of degradation within 1 h, which was about 90 %, methyl orange shows about 80 %, and methyl blue shows the lowest degradation, around 60 %.","PeriodicalId":510356,"journal":{"name":"International Journal of Materials Research","volume":" December","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141824082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Site preference, structural stability and mechanical properties of Mg2Si doped by ternary elements were studied by first-principles calculation. Formation enthalpies show that light element impurity Al and rare earth elements Sc and Y tend to occupy the Mg site, while transition element Cu has a preference for the Si site. Shear modulus to bulk modulus ratio (G/B), Poisson’s ratio ν and Cauchy pressure show that the ductility of Mg2Si is improved for ternary element addition. The introduced parameter of ductility factor D indicates that the enhanced dislocation emission but suppressed micro-crack propagation is the key to enhancing ductility. Electronic structure indicates the brittleness is due to the strong covalent interaction between Mg-2p and Si-3p (Mg-3s and Si-3p/3s). While, with the incorporation of alloying elements, abundant electrons are injected into the matrix Mg2Si. Thereby, the covalent interaction is effectively suppressed and the ductility is improved.
通过第一原理计算研究了三元元素掺杂的 Mg2Si 的位点偏好、结构稳定性和力学性能。形成焓表明，轻元素杂质 Al 和稀土元素 Sc 和 Y 倾向于占据 Mg 位点，而过渡元素 Cu 则更倾向于占据 Si 位点。剪切模量与体积模量比（G/B）、泊松比ν和考奇压力表明，添加三元元素后，Mg2Si 的延展性得到改善。引入的延性因子参数 D 表明，增强位错发射但抑制微裂纹扩展是提高延性的关键。电子结构表明，脆性是由于 Mg-2p 和 Si-3p 之间的强共价作用（Mg-3s 和 Si-3p/3s）造成的。而随着合金元素的加入，大量电子被注入基体 Mg2Si。因此，共价作用被有效抑制，延展性得到改善。
{"title":"First-principles calculations of the mechanical properties of Mg2Si intermetallic via ternary elements doping","authors":"Hai-Wei Hu, Tinging Liu, Zhendong Li, Xu Wang, Yanbiao Wang, Shaorong Li","doi":"10.1515/ijmr-2023-0274","DOIUrl":"https://doi.org/10.1515/ijmr-2023-0274","url":null,"abstract":"\u0000 Site preference, structural stability and mechanical properties of Mg2Si doped by ternary elements were studied by first-principles calculation. Formation enthalpies show that light element impurity Al and rare earth elements Sc and Y tend to occupy the Mg site, while transition element Cu has a preference for the Si site. Shear modulus to bulk modulus ratio (G/B), Poisson’s ratio ν and Cauchy pressure show that the ductility of Mg2Si is improved for ternary element addition. The introduced parameter of ductility factor D indicates that the enhanced dislocation emission but suppressed micro-crack propagation is the key to enhancing ductility. Electronic structure indicates the brittleness is due to the strong covalent interaction between Mg-2p and Si-3p (Mg-3s and Si-3p/3s). While, with the incorporation of alloying elements, abundant electrons are injected into the matrix Mg2Si. Thereby, the covalent interaction is effectively suppressed and the ductility is improved.","PeriodicalId":510356,"journal":{"name":"International Journal of Materials Research","volume":" 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141831030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, the risk of blast attacks on underwater tunnels, important transportation routes, has increased due to the growing prevalence of vicious regional conflicts and global terrorist activities. In this work, we investigate the blast impact behavior of underwater tunnels filled with honeycomb core and covered by solid panels. The core is composed of 3D auxetic materials with high energy absorption compared to conventional honeycombs. In order to improve the stiffness of the auxetic structures, a pair of crossed rods is introduce to each cell. The relative densities of 3D auxetic structures are derived theoretically. The coupling effects of the geometrical parameters on the relative density are investigated. Then the deformation patterns of the underwater tunnels at different blast heights are analyzed. The kinetic energy and absorbed energy are discussed for tunnels with 3D auxetic materials and solid materials. Results show that tunnels composed with 3D reinforced auxetic structures can absorb much more energy than solid ones. Moreover, localized damage is observed which means greater chance of survival and smaller repairs after extreme impact. Finally, a stiffness-improved 3D reinforced auxetic structure is presented to enhance the tunnel’s strength and stability further.
{"title":"Blast protection of underwater tunnels with 3D auxetic materials","authors":"Shuwen Zhang, Tao Fan","doi":"10.1515/ijmr-2022-0461","DOIUrl":"https://doi.org/10.1515/ijmr-2022-0461","url":null,"abstract":"\u0000 In recent years, the risk of blast attacks on underwater tunnels, important transportation routes, has increased due to the growing prevalence of vicious regional conflicts and global terrorist activities. In this work, we investigate the blast impact behavior of underwater tunnels filled with honeycomb core and covered by solid panels. The core is composed of 3D auxetic materials with high energy absorption compared to conventional honeycombs. In order to improve the stiffness of the auxetic structures, a pair of crossed rods is introduce to each cell. The relative densities of 3D auxetic structures are derived theoretically. The coupling effects of the geometrical parameters on the relative density are investigated. Then the deformation patterns of the underwater tunnels at different blast heights are analyzed. The kinetic energy and absorbed energy are discussed for tunnels with 3D auxetic materials and solid materials. Results show that tunnels composed with 3D reinforced auxetic structures can absorb much more energy than solid ones. Moreover, localized damage is observed which means greater chance of survival and smaller repairs after extreme impact. Finally, a stiffness-improved 3D reinforced auxetic structure is presented to enhance the tunnel’s strength and stability further.","PeriodicalId":510356,"journal":{"name":"International Journal of Materials Research","volume":"119 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141105716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Double compression tests were performed on vanadium–titanium microalloyed steels with different nitrogen contents by using a Gleeble-3800 thermo-mechanical simulator to study the softening behaviors of the deformed austenite during different time intervals between the two passes. The static recrystallization fractions were calculated by the stress offset method and static recrystallization diagrams for the tested steels were obtained. The effects of deformation temperature and interval time on the softening behaviors were analyzed. Especially, the effect of nitrogen on the softening behaviors of the tested steels is discussed in detail. The results showed that the softening behaviors of the tested steels with various nitrogen contents are different. As far as the steel with low nitrogen content is concerned, the softening fraction increases monotonically with increasing time interval, and higher temperature can promote the static recrystallization. However, with more nitrogen added into vanadium–titanium microalloyed steel, precipitated particles of vanadium titanium carbonitride can be observed in the tested steel at the temperature of 850 °C or 800 °C, which leads to the formation of plateaus on the softening curves. An increase in nitrogen content in the steel is favorable for vanadium titanium carbonitride precipitation, which leads to a stronger prohibition of static recrystallization and a longer plateau on the softening curves. Moreover, the precipitated particles in the tested steel will not play an inhibition role in static recrystallization until the nitrogen content in the steel reaches a critical value.
{"title":"Effect of nitrogen content on the static recrystallization and precipitation behaviors of vanadium–titanium microalloyed steels","authors":"Baochun Zhao, Tan Zhao, Lei Huang, Junbo Li","doi":"10.1515/ijmr-2023-0122","DOIUrl":"https://doi.org/10.1515/ijmr-2023-0122","url":null,"abstract":"\u0000 Double compression tests were performed on vanadium–titanium microalloyed steels with different nitrogen contents by using a Gleeble-3800 thermo-mechanical simulator to study the softening behaviors of the deformed austenite during different time intervals between the two passes. The static recrystallization fractions were calculated by the stress offset method and static recrystallization diagrams for the tested steels were obtained. The effects of deformation temperature and interval time on the softening behaviors were analyzed. Especially, the effect of nitrogen on the softening behaviors of the tested steels is discussed in detail. The results showed that the softening behaviors of the tested steels with various nitrogen contents are different. As far as the steel with low nitrogen content is concerned, the softening fraction increases monotonically with increasing time interval, and higher temperature can promote the static recrystallization. However, with more nitrogen added into vanadium–titanium microalloyed steel, precipitated particles of vanadium titanium carbonitride can be observed in the tested steel at the temperature of 850 °C or 800 °C, which leads to the formation of plateaus on the softening curves. An increase in nitrogen content in the steel is favorable for vanadium titanium carbonitride precipitation, which leads to a stronger prohibition of static recrystallization and a longer plateau on the softening curves. Moreover, the precipitated particles in the tested steel will not play an inhibition role in static recrystallization until the nitrogen content in the steel reaches a critical value.","PeriodicalId":510356,"journal":{"name":"International Journal of Materials Research","volume":"21 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141105250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, the effects of Mo additions on the microstructure, hardness and bending strength of TiC–Fe cermets manufactured by spark plasma sintering were investigated by scanning electron microscopy, X-ray diffraction and mechanical properties tests. Thermodynamic calculations were utilized to analyze the evolution of the microstructure. The results show that the conventional core/rim structure was not formed during the solid-phase sintering of TiC–Fe cermets. The heat-treatment process and reasonable Mo addition can effectively enhance the overall performance of the alloys. With the addition of minor Mo, the hardness of the sintered cermets improved significantly, which was attributed to the solid solution strengthening mechanism of Mo in Fe binder. However, excessive Mo exceeded the solubility range of Fe binder and precipitated in the form of M 6C and Mo2C phases, which damaged the bending strength of the heat-treated cermets.
本研究通过扫描电子显微镜、X 射线衍射和机械性能测试，研究了添加 Mo 对火花等离子烧结制造的 TiC-Fe 金属陶瓷的微观结构、硬度和弯曲强度的影响。热力学计算用于分析微观结构的演变。结果表明，在 TiC-Fe 金属陶瓷的固相烧结过程中没有形成传统的核心/边缘结构。热处理工艺和合理的钼添加能有效提高合金的整体性能。添加少量钼后，烧结金属陶瓷的硬度显著提高，这归因于钼在铁粘结剂中的固溶强化机制。然而，过量的钼超过了铁粘合剂的溶解范围，并以 M 6C 和 Mo2C 相的形式析出，从而破坏了热处理后的金属陶瓷的抗弯强度。
{"title":"Experimental investigation and thermodynamic analysis of TiC–Fe cermets with Mo additions","authors":"Yafei Pan, Lei Huang, Yong Du","doi":"10.1515/ijmr-2023-0199","DOIUrl":"https://doi.org/10.1515/ijmr-2023-0199","url":null,"abstract":"\u0000 In this study, the effects of Mo additions on the microstructure, hardness and bending strength of TiC–Fe cermets manufactured by spark plasma sintering were investigated by scanning electron microscopy, X-ray diffraction and mechanical properties tests. Thermodynamic calculations were utilized to analyze the evolution of the microstructure. The results show that the conventional core/rim structure was not formed during the solid-phase sintering of TiC–Fe cermets. The heat-treatment process and reasonable Mo addition can effectively enhance the overall performance of the alloys. With the addition of minor Mo, the hardness of the sintered cermets improved significantly, which was attributed to the solid solution strengthening mechanism of Mo in Fe binder. However, excessive Mo exceeded the solubility range of Fe binder and precipitated in the form of M\u0000 6C and Mo2C phases, which damaged the bending strength of the heat-treated cermets.","PeriodicalId":510356,"journal":{"name":"International Journal of Materials Research","volume":"56 51","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141108520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ehud Almog, Chen Nachmias, Nadav Orion, Jonathan Zimmerman, A. Bisht, L. Klinger, E. Rabkin
We deposited a 30 nm-thick Au film on single crystalline KBr substrate and studied the solid state dewetting behavior of the film at a temperature of 350 °C. At this temperature, the ions of the KBr compound exhibit significant mobility along the Au–KBr interface, which affects the morphology and kinetics of the solid state dewetting. We performed statistical morphology analysis of the Au–KBr interface by selectively dissolving the KBr substrate after the dewetting heat treatments and subsequent atomic force microscopy imaging of the “upside-down” oriented Au film. We demonstrated that atomic mobility at the interface leads to embedding of the partially dewetted Au film into the KBr substrate. We proposed a quantitative model of the shape evolution of a disc-shaped Au particle on the KBr substrate under the condition of finite interface mobility of the substrate species. The model predictions were consistent with the experimentally observed sinking rates of Au nanostructures.
{"title":"Dewetting upside-down: two-sided solid state dewetting of thin gold film on soft KBr substrate","authors":"Ehud Almog, Chen Nachmias, Nadav Orion, Jonathan Zimmerman, A. Bisht, L. Klinger, E. Rabkin","doi":"10.1515/ijmr-2023-0124","DOIUrl":"https://doi.org/10.1515/ijmr-2023-0124","url":null,"abstract":"\u0000 We deposited a 30 nm-thick Au film on single crystalline KBr substrate and studied the solid state dewetting behavior of the film at a temperature of 350 °C. At this temperature, the ions of the KBr compound exhibit significant mobility along the Au–KBr interface, which affects the morphology and kinetics of the solid state dewetting. We performed statistical morphology analysis of the Au–KBr interface by selectively dissolving the KBr substrate after the dewetting heat treatments and subsequent atomic force microscopy imaging of the “upside-down” oriented Au film. We demonstrated that atomic mobility at the interface leads to embedding of the partially dewetted Au film into the KBr substrate. We proposed a quantitative model of the shape evolution of a disc-shaped Au particle on the KBr substrate under the condition of finite interface mobility of the substrate species. The model predictions were consistent with the experimentally observed sinking rates of Au nanostructures.","PeriodicalId":510356,"journal":{"name":"International Journal of Materials Research","volume":"7 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139524657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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