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Keywords = in situ SEM tensile

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26 pages, 7824 KiB  
Article
Microstructural Synergy of ZrC-NbC Reinforcements and Its Coupled Effects on Mechanical and Dynamic Properties of Titanium Matrix Composites
by Juan Wang, Haijun Zhang, Baiqing Zhou and Zhong Yang
Metals 2025, 15(6), 573; https://doi.org/10.3390/met15060573 - 22 May 2025
Viewed by 407
Abstract
In aerospace applications, titanium matrix composites (TMCs) must balance high strength, thermal stability, and vibration resistance. This study investigates the microstructural evolution and multi-property correlations in single-phase ZrC-reinforced (TMC1) and dual-phase ZrC-NbC-co-reinforced (TMC2) TMCs via SEM/TEM, XRD, tensile testing, and ANSYS simulations. The [...] Read more.
In aerospace applications, titanium matrix composites (TMCs) must balance high strength, thermal stability, and vibration resistance. This study investigates the microstructural evolution and multi-property correlations in single-phase ZrC-reinforced (TMC1) and dual-phase ZrC-NbC-co-reinforced (TMC2) TMCs via SEM/TEM, XRD, tensile testing, and ANSYS simulations. The in situ reaction (Ti + ZrC/NbC → TiC + Zr/Nb) and NbC-induced grain boundary pinning drive microstructural optimization in TMC2, achieving 30% higher reinforcement homogeneity and 5 μm grain refinement from 15 μm to 10 μm. TMC2’s tensile strength reaches 1210 MPa, a 15% increase over TMC1, with an elongation at a break of 4.74%, 2.2 times that of TMC1. This performance stems from synergistic Hall–Petch strengthening and nano-TiC dispersion strengthening. Modal simulations show TMC2 exhibits a first-mode natural frequency of 98.5 kHz, 1.1% higher than TMC1’s 97.4 kHz, with maximum displacement reduced by 2.3%. These improvements correlate with TMC2’s elevated elastic modulus (125 GPa vs. 110 GPa) and uniform mass/stiffness distribution. The ZrC-NbC synergy establishes a microstructural framework for the concurrent enhancement of static and dynamic properties, offering critical insights for a high-performance TMC design in extreme environments. Full article
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11 pages, 3775 KiB  
Article
Deformation Behavior of S32750 Duplex Stainless Steel Based on In Situ EBSD Technology
by Shun Bao, Han Feng, Zhigang Song, Jianguo He, Xiaohan Wu and Yang Gu
Materials 2025, 18(9), 2030; https://doi.org/10.3390/ma18092030 - 29 Apr 2025
Viewed by 457
Abstract
In this study, we investigated the two-phase hardening behavior and microstructural evolution of S32750 duplex stainless steel during the tensile deformation process. The analysis was conducted using in situ electron backscatter diffraction (EBSD), scanning electron microscopy (SEM), and microhardness testing. It was observed [...] Read more.
In this study, we investigated the two-phase hardening behavior and microstructural evolution of S32750 duplex stainless steel during the tensile deformation process. The analysis was conducted using in situ electron backscatter diffraction (EBSD), scanning electron microscopy (SEM), and microhardness testing. It was observed that strain transfer occurred between the two phases in the position away from the fracture. The ferrite phase exhibited softening, while the austenite phase underwent hardening. In the region less than 1 mm from the fracture site, both phases experienced a rapid hardening, with the maximum hardness difference between the two phases near the fracture reaching approximately 45 HV. In situ EBSD results indicate that the kernel average misorientation (KAM) value for the ferrite phase consistently exceeds that of the austenite phase during the initial stages of deformation. Conversely, in the final stages of deformation, the KAM value for austenite surpasses that of ferrite. In the initial stage of deformation, the type of grain boundaries in both phases remains largely unaltered. However, in the later stages of deformation, there is a marked increase in the number of small-angle grain boundaries within ferrite, which become approximately three times that of the large-angle grain boundaries. As deformation progresses, the maximum orientation distribution density of the ferrite phase is reduced by approximately 50%, with the preferred orientation shifting from the {100} plane to the {111} plane. In contrast, the orientation distribution of the austenite remains relatively uniform, with no significant change in the maximum orientation distribution density observed. This indicates that after substantial deformation, the rotation of ferrite grains significantly increases the deformation resistance, whereas the austenite phase continues to harden. This differential behavior leads to the continuous accumulation of strain at the phase boundaries, ultimately causing cracks to form at these boundaries and resulting in the sample’s fracture. Full article
(This article belongs to the Special Issue From Materials to Applications: High-Performance Steel Structures)
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19 pages, 13447 KiB  
Article
Study on the Microstructure and Mechanical Properties of 7085 Aluminum Alloy Reinforced by In Situ (ZrB2 + Al2O3) Nanoparticles and Rare Earth Er
by Yuqiang Zhang, Yutao Zhao, Xizhou Kai, Jiadong Yang, Hanfei Zhu and Ying Shan
Materials 2025, 18(9), 2009; https://doi.org/10.3390/ma18092009 - 29 Apr 2025
Viewed by 571
Abstract
This study investigates the synergistic strengthening effects of in situ synthesized nano (ZrB2 + Al2O3) particles and rare earth Er microalloying on the microstructure and mechanical properties of 7085 aluminum alloy. The composite material was prepared through a [...] Read more.
This study investigates the synergistic strengthening effects of in situ synthesized nano (ZrB2 + Al2O3) particles and rare earth Er microalloying on the microstructure and mechanical properties of 7085 aluminum alloy. The composite material was prepared through a melt direct reaction combined with rolling and T6 heat treatment, with microstructural evolution characterized by metallurgical microscopy, XRD, and SEM. Results demonstrate that the addition of 3 vol.% in situ nano (ZrB2 + Al2O3) particles optimally enhances both strength and toughness, achieving a tensile strength of 635.4 MPa (16.2% increase) and elongation after fracture of 16.2% (14.9% improvement) compared to the matrix alloy. Excessive particle content (5 vol.%) leads to severe clustering and deteriorated interfacial bonding, causing performance degradation. Introducing 0.3 wt.% Er improves particle distribution uniformity and promotes Al3(Er,Zr) precipitate formation, refining grains and strengthening interfaces. This further elevates tensile strength to 654.8 MPa (19.7% increase) and elongation to 16.6% (17.7% improvement). The research reveals the synergistic optimization mechanism between particle content and Er addition, providing theoretical support for designing high-performance aluminum matrix composites. Full article
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18 pages, 20166 KiB  
Article
Degradation Characteristics of Coal Samples Under the Dry–Wet Cycle Action of Acidic, High-Salinity Solutions: Experimental Study and Fractal Analysis
by Leiming Zhang, Min Wang, Bin Zhang, Xun Xi, Ying Zhang and Jiliang Pan
Fractal Fract. 2025, 9(4), 221; https://doi.org/10.3390/fractalfract9040221 - 1 Apr 2025
Viewed by 471
Abstract
Uniaxial compression tests were conducted on coal samples subjected to different dry–wet cycling treatments to investigate the damage and degradation mechanisms of coal samples under the dry–wet cyclic action of acidic, high-salinity solutions. The damage process of the coal samples was monitored in [...] Read more.
Uniaxial compression tests were conducted on coal samples subjected to different dry–wet cycling treatments to investigate the damage and degradation mechanisms of coal samples under the dry–wet cyclic action of acidic, high-salinity solutions. The damage process of the coal samples was monitored in situ using acoustic emission (AE). The degradation evolution of the mechanical parameters and macroscopic failure modes with the number of cycles was analyzed. Based on the AE ringing parameters, the RA-AF distribution and the AE fractal dimension’s variation characteristics were studied. Additionally, scanning electron microscopy (SEM) was used to observe the microstructure of the coal samples. The results showed that with the increase in the number of dry–wet cycles, both the peak strength and elastic modulus of the coal samples exhibited varying degrees of degradation, and the failure mode gradually shifted from tensile failure to shear failure. AE ringing counts decreased progressively, while the proportion of shear cracks based on the RA-AF classification increased. At the same time, the mean AE fractal dimension of the coal samples increased, and the fractal dimension decreased with an increase in AE ringing counts. The sharp drop in fractal dimensions could serve as an early warning signal for a major failure in the coal samples. Furthermore, under the influence of dry–wet cycling in acidic, high-salinity solutions, defects such as pores and cracks in the microstructure of the coal samples became more pronounced, and the degradation effect continuously intensified. Full article
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13 pages, 7449 KiB  
Article
A Study on the Microstructure and Mechanical Properties of Improved 25Ni-20Cr Steel via in Situ Testing
by Penghui Lei, Xiaoyu Ji, Jiahao Chen, Yunhao Huang, Nan Lv, Yulin Fan, Yongchao Hou, Xinsheng Shi and Di Yun
Nanomaterials 2025, 15(6), 413; https://doi.org/10.3390/nano15060413 - 7 Mar 2025
Viewed by 658
Abstract
To meet the application requirements for structural components in Gen-IV nuclear reactors, it is essential to improve the high-temperature mechanical properties of 25Ni-20Cr (S35140) austenitic stainless steel. In this research, an improved austenitic stainless steel (N-S35140), derived from S35140 steel, was investigated. The [...] Read more.
To meet the application requirements for structural components in Gen-IV nuclear reactors, it is essential to improve the high-temperature mechanical properties of 25Ni-20Cr (S35140) austenitic stainless steel. In this research, an improved austenitic stainless steel (N-S35140), derived from S35140 steel, was investigated. The scanning transmission electron microscopy (STEM) results indicate that the addition of titanium (Ti) microalloying elements to S35140 steel led to the precipitation of new strengthening nano phases, including M(C, N), MC, MN and Ti(C, N), in N-S35140. These precipitates effectively compensated for the loss of high-temperature strength resulting from the substantial reduction in carbon content. During the in situ transmission electron microscopy (TEM) compressive process at room temperature, the yield strength of N-S35140 steel is 618.4 MPa. At room temperature, the tensile strength of N-S35140 steel is 638.5 MPa, with a yield strength of 392.8 MPa and an elongation of 32.7%, which surpasses those of S35140 steel at room temperature. N-S35140 steel exhibits a tensile strength of 330.6 MPa, a yield strength of 228.2 MPa, and an elongation of 51.4% during the in situ scanning electron microscopy (SEM) tensile test conducted at 650 °C. As a consequence, the improved N-S35140 steel demonstrates significantly enhanced mechanical properties compared to the original S35140 steel, positioning it as a promising candidate for structural components in Gen-IV nuclear reactors. Full article
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12 pages, 3968 KiB  
Article
Comparison of Interfaces Between In Situ Laser Beam Deposition Forming and Electron Beam Welding for Thick-Walled Titanium Alloy Structures
by Pingchuan Yang, Fei Li, Zongtao Zhu and Hui Chen
Micromachines 2024, 15(11), 1383; https://doi.org/10.3390/mi15111383 - 15 Nov 2024
Viewed by 1042
Abstract
An investigation was conducted on electron beam-welded and additively manufactured joints on a thick-walled titanium alloy utilizing in situ laser beam deposition and electron beam welding techniques. The surface morphology, microstructural characteristics, and mechanical properties of both joint types were comprehensively analyzed using [...] Read more.
An investigation was conducted on electron beam-welded and additively manufactured joints on a thick-walled titanium alloy utilizing in situ laser beam deposition and electron beam welding techniques. The surface morphology, microstructural characteristics, and mechanical properties of both joint types were comprehensively analyzed using stereomicroscopy, scanning electron microscopy (SEM), microhardness and tensile strength testing, and electron backscatter diffraction (EBSD) techniques. The electron-beam-welded joint exhibited distinct fusion and heat-affected zones, whereas the laser-beam-deposited joint exhibited a smoother surface that was free from excess spatter. Both joints featured a sharp microstructural boundary with a pronounced hardness gradient across the interface, lacking a gradual transition area. During tensile testing, both joint types demonstrated a mixed brittle-ductile fracture mode; however, the electron beam-welded joints surpassed the laser-beam-deposited joints in terms of tensile strength, achieving over 1183 MPa with an elongation of more than 7.3%, compared to 1123 MPa and 5.9% elongation, respectively. Full article
(This article belongs to the Special Issue Future Prospects of Additive Manufacturing)
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23 pages, 21404 KiB  
Article
Organic–Inorganic Hybridization of Silkworm Cocoon Filaments Using Nano Pastes of Silica–Phosphate–M (M = Cu, Fe, or Al)
by I Wayan Karyasa, Enike Dwi Kusumawati, Retno Agustarini, Lincah Andadari and Herman Sari
Nanomaterials 2024, 14(21), 1697; https://doi.org/10.3390/nano14211697 - 23 Oct 2024
Viewed by 1302
Abstract
Inorganic–organic hybrid biomaterials have recently attracted much attention because of their widespread use. Silkworm cocoon filaments resulting from sericulture as prospective nanobiomaterials need to be improved, and their properties need to be used for broader purposes. This study was aimed at investigating methods [...] Read more.
Inorganic–organic hybrid biomaterials have recently attracted much attention because of their widespread use. Silkworm cocoon filaments resulting from sericulture as prospective nanobiomaterials need to be improved, and their properties need to be used for broader purposes. This study was aimed at investigating methods for siliconization of silkworm cocoon filaments and characterizing their cocoon filament properties in terms of their yarn quality, natural dyeing, and antibacterial properties. Three methods of hybridization processes were used in this experiment, namely, in situ natural dyeing of silk yarns while silk filaments were spined, feed engineering through spraying the mulberry leaves with natural dyes and silica–phosphate–M (M = Cu, Fe, or Al) nano pastes, and a combination of both methods. The resulting cocoon filaments were characterized by their siliconization of filament fibers by using FTIR, XRD, and SEM-EDS methods. The yarn tensile strength, color quality, color fastness properties affected by the siliconization of silk filament fibers, and antibacterial properties were also investigated. Results showed that the combination method produced better siliconization of silk fibers, and, consequently, the better siliconization of silk fibers produced better natural dyeing as well as antibacterial properties of their resulting silk yarns. Full article
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12 pages, 1349 KiB  
Article
Mechanical Properties of Silicon Nitride in Different Morphologies: In Situ Experimental Analysis of Bulk and Whisker Structures
by Bokang Wang, Tanglong Bai, Weide Wang and Hongti Zhang
Materials 2024, 17(18), 4549; https://doi.org/10.3390/ma17184549 - 16 Sep 2024
Cited by 1 | Viewed by 1742
Abstract
Silicon nitride (Si3N4) is widely used in structural ceramics and advanced manufacturing due to its excellent mechanical properties and high-temperature stability. These applications always involve deformation under mechanical loads, necessitating a thorough understanding of their mechanical behavior and performance [...] Read more.
Silicon nitride (Si3N4) is widely used in structural ceramics and advanced manufacturing due to its excellent mechanical properties and high-temperature stability. These applications always involve deformation under mechanical loads, necessitating a thorough understanding of their mechanical behavior and performance under load. However, the mechanical properties of Si3N4, particularly at the micro- and nanoscale, are not well understood. This study systematically investigated the mechanical properties of bulk Si3N4 and Si3N4 whiskers using in situ SEM indentation and uniaxial tensile strategies. First, nanoindentation tests on bulk Si3N4 at different contact depths ranging from 125 to 450 nm showed significant indentation size effect on modulus and hardness, presumably attributed to the strain gradient plasticity theory. Subsequently, in situ uniaxial tensile tests were performed on Si3N4 whiskers synthesized with two different sintering aids, MgSiN2 and Y2O3. The results indicated that whiskers sintered with Y2O3 exhibited higher modulus and strength compared to those sintered with MgSiN2. This work provides a deeper understanding of the mechanical behavior of Si3N4 at the micro- and nanoscale and offers guidance for the design of high-performance Si3N4 ceramic whiskers. Full article
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17 pages, 23305 KiB  
Article
In Situ Investigation of Tensile Response for Inconel 718 Micro-Architected Materials Fabricated by Selective Laser Melting
by Ioannis Filippos Kyriakidis, Nikolaos Kladovasilakis, Eleftheria Maria Pechlivani, Apostolos Korlos, Constantine David and Konstantinos Tsongas
Materials 2024, 17(17), 4433; https://doi.org/10.3390/ma17174433 - 9 Sep 2024
Cited by 4 | Viewed by 1604
Abstract
Topology optimization enables the design of advanced architected materials with tailored mechanical properties and optimal material distribution. This method can result in the production of parts with uniform mechanical properties, reducing anisotropy effects and addressing a critical challenge in metal additive manufacturing (AM). [...] Read more.
Topology optimization enables the design of advanced architected materials with tailored mechanical properties and optimal material distribution. This method can result in the production of parts with uniform mechanical properties, reducing anisotropy effects and addressing a critical challenge in metal additive manufacturing (AM). The current study aims to examine the micro-tensile response of Inconel 718 architected materials utilizing the Selective Laser Melting Technique. In this context, three novel architected materials, i.e., Octet, Schwarz Diamond (SD), and hybrid Schwarz Diamond and Face Centered Cubic (FCC), were tested in three different relative densities. The specimens were then subjected to uniaxial quasi-static tensile tests to determine their key mechanical properties, including elastic modulus, yield strength, and ultimate tensile strength (UTS), as well as the scaling laws describing the tensile response of each architected material. In situ Scanning Electron Microscopy (SEM) has been performed to observe the structure and grain morphology of the 3D printed specimens along with the phase transitions (elastic, plastic), the crack propagation, and the overall failure mechanisms. The results highlight the effect of the lattice type and the relative density on the mechanical properties of architected materials. Topologically optimized structures presented a 70–80% reduction in overall strength, while the SD and SD&FCC structures presented higher stretching dominated behavior, which was also verified by the n-value range (1–2) extracted from the identification of the scaling laws. Full article
(This article belongs to the Special Issue Fusion Bonding/Welding of Metal and Non-Metallic Materials)
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14 pages, 8217 KiB  
Article
In Situ Study of Precipitates’ Effect on Grain Deformation Behavior and Mechanical Properties of S31254 Super Austenitic Stainless Steel
by Jinyao Ma, Huanyu Tan, Nan Dong, Jiemin Gao, Puli Wang, Zhihua Wang and Peide Han
Materials 2024, 17(11), 2676; https://doi.org/10.3390/ma17112676 - 1 Jun 2024
Viewed by 1387
Abstract
Grain boundary (GB) precipitation-induced cracking is a significant issue for S31254 super austenitic stainless steel during hot working. Investigating the deformation behavior based on precipitate morphology and distribution is essential. In this study, continuous smaller and intermittent larger precipitates were obtained through heat [...] Read more.
Grain boundary (GB) precipitation-induced cracking is a significant issue for S31254 super austenitic stainless steel during hot working. Investigating the deformation behavior based on precipitate morphology and distribution is essential. In this study, continuous smaller and intermittent larger precipitates were obtained through heat treatments at 950 °C and 1050 °C. The microstructure evolution and mechanical properties influenced by precipitates were experimentally investigated using an in situ tensile stage inside a scanning electron microscope (SEM) combined with electron backscatter diffraction (EBSD). The results showed that continuous precipitates at 950 °C had a stronger pinning effect on the GB, making grain rotation difficult and promoting slip deformation in the plastic interval. Continuous precipitates caused severe stress concentration near GB and reduced coordinated deformation ability. Additionally, the crack propagation path changed from transcrystalline to intercrystalline. Furthermore, internal precipitates were a crucial factor affecting the initial crack nucleation position. Interconnected precipitates led to an intergranular fracture tendency and severe deterioration of the material’s plasticity, as observed in fracture morphology. Full article
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21 pages, 6866 KiB  
Article
Gamma Radiation-Mediated Synthesis of Antimicrobial Polyurethane Foam/Silver Nanoparticles
by Eduard-Marius Lungulescu, Radu Claudiu Fierascu, Miruna S. Stan, Irina Fierascu, Elena Andreea Radoi, Cristina Antonela Banciu, Raluca Augusta Gabor, Toma Fistos, Luminita Marutescu, Marcela Popa, Ionela C. Voinea, Sorina N. Voicu and Nicoleta-Oana Nicula
Polymers 2024, 16(10), 1369; https://doi.org/10.3390/polym16101369 - 10 May 2024
Cited by 6 | Viewed by 2029
Abstract
Nosocomial infections represent a major threat within healthcare systems worldwide, underscoring the critical need for materials with antimicrobial properties. This study presents the development of polyurethane foam embedded with silver nanoparticles (PUF/AgNPs) using a rapid, eco-friendly, in situ radiochemical synthesis method. The nanocomposites [...] Read more.
Nosocomial infections represent a major threat within healthcare systems worldwide, underscoring the critical need for materials with antimicrobial properties. This study presents the development of polyurethane foam embedded with silver nanoparticles (PUF/AgNPs) using a rapid, eco-friendly, in situ radiochemical synthesis method. The nanocomposites were characterized by UV–vis and FTIR spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray technique (SEM/EDX), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), tensile and compression strengths, antimicrobial activity, and foam toxicity tests. The resulting PUF/AgNPs demonstrated prolonged stability (over 12 months) and good dispersion of AgNPs. Also, the samples presented higher levels of hardness compared to samples without AgNPs (deformation of 1682 µm for V1 vs. 4307 µm for V0, under a 5 N force), tensile and compression strength of 1.80 MPa and 0.34 Mpa, respectively. Importantly, they exhibited potent antimicrobial activity against a broad range of bacteria (including Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, and Enterococcus faecalis) and a fungal mixture (no fungal growth on the sample surface was observed after 28 days of exposure). Furthermore, these materials were non-toxic to human keratinocytes, which kept their specific morphology after 24 h of incubation, highlighting their potential for safe use in biomedical applications. We envision promising applications for PUF/AgNPs in hospital bed mattresses and antimicrobial mats, offering a practical strategy to reduce nosocomial infections and enhance patient safety within healthcare facilities. Full article
(This article belongs to the Special Issue Polymer-Based Materials for Drug Delivery and Biomedical Applications)
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13 pages, 7537 KiB  
Article
Influence of Strong Shear Field on Structure and Performance of HDPE/PA6 In Situ Microfibril Composites
by Junwen Zhang, Yiwei Zhang, Yanjiang Li, Mengna Luo and Jie Zhang
Polymers 2024, 16(8), 1032; https://doi.org/10.3390/polym16081032 - 10 Apr 2024
Cited by 1 | Viewed by 1479
Abstract
As one of the most widely applied general-purpose plastics, high-density polyethylene (HDPE) exhibits good comprehensive performance. However, mechanical strength limits its wider application. In this work, we introduced the engineering plastic PA6 as a dispersed phase to modify the HDPE matrix and applied [...] Read more.
As one of the most widely applied general-purpose plastics, high-density polyethylene (HDPE) exhibits good comprehensive performance. However, mechanical strength limits its wider application. In this work, we introduced the engineering plastic PA6 as a dispersed phase to modify the HDPE matrix and applied multiple shears generated by vibration to the polymer melt during the packing stage of injection molding. SEM, 2D-WXRD and 2D-SAXS were used to characterize the morphology and structure of the samples. The results show that under the effect of a strong shear field, the dispersed phase in the composites can form in situ microfibers and numerous high-strength shish-kebab and hybrid shish-kebab structures are formed. Additionally, the distribution of fibers and high-strength oriented structures in the composites expands to the core region with the increase in vibration times. As a result, the tensile strength, tensile modulus and surface hardness of VIM-6 can reach a high level of 66.5 MPa, 981.4 MPa and 72, respectively. Therefore, a high-performance HDPE product is successfully prepared in this study, which is of great importance for expanding the application range of HDPE products. Full article
(This article belongs to the Special Issue Injection Molding of Polymers and Polymer Composites)
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13 pages, 6273 KiB  
Article
In Situ Polymerization of Antibacterial Modification Polyamide 66 with Au@Cu2O-ZnO Ternary Heterojunction
by Xiang Li, Mi Zheng, Shikun Zhao, Zhiwen Cao, Kai Pan, Xinxing Feng, Hua Zhang, Min Zheng and Cheng Wang
Polymers 2024, 16(1), 158; https://doi.org/10.3390/polym16010158 - 4 Jan 2024
Cited by 2 | Viewed by 2222
Abstract
In situ polymerization has proven to be an effective route through which to introduce function materials into polyamide materials. In this work, a nano-heterojunction material was evenly dispersed in PA66 via in situ polymerization methods to yield the antimicrobial PA66. The composites showed [...] Read more.
In situ polymerization has proven to be an effective route through which to introduce function materials into polyamide materials. In this work, a nano-heterojunction material was evenly dispersed in PA66 via in situ polymerization methods to yield the antimicrobial PA66. The composites showed excellent antibacterial activity against Staphylococcus aureus and Escherichia coli, with strong mechanical properties. Fourier transform infrared spectroscopy (FTIR) showed that metal ions reacted with oxygen-containing functional groups. In addition, the shift of oxygen peaks in XPS spectra confirmed the occurrence of a complexation reaction. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) confirmed the effect of nano-heterojunction, which induced crystallization. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed uniform dispersion of heterojunctions in PA66. Tensile testing revealed decreased toughness with higher loadings. The nanocomposite polyamide material has good processing properties which can be processed into thin films, molds, and wires without changing the morphology, and can be widely used in a variety of fields. Full article
(This article belongs to the Section Polymer Composites and Nanocomposites)
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19 pages, 8138 KiB  
Article
Effect of Pre-Added HfO2 Inclusions on Carbide Morphology and Deformation Behavior in DZ125 Nickel-Based Superalloy
by Haoyuan Feng, Furong Liu, Qin Wang, Dinggang Wang, Jinxia Song, Chengbo Xiao and Yuhong Wu
Metals 2024, 14(1), 57; https://doi.org/10.3390/met14010057 - 3 Jan 2024
Cited by 4 | Viewed by 1650
Abstract
Inclusions are important phases affecting material properties in complicated ways. In this paper, a quantitative study of the addition of HfO2 inclusions to DZ125 nickel-based superalloys was performed. Experimental results showed that the introduction of HfO2 inclusions caused a loss of [...] Read more.
Inclusions are important phases affecting material properties in complicated ways. In this paper, a quantitative study of the addition of HfO2 inclusions to DZ125 nickel-based superalloys was performed. Experimental results showed that the introduction of HfO2 inclusions caused a loss of strength and ductility. The carbide morphology also changed significantly from skeletal-shaped to block-shaped, resulting in a remarkable discrepancy in the fracture behavior under quasi-in-situ tensile testing. The SEM dynamic observations showed that cracks were initiated from the skeletal carbides and almost failed to propagate into the matrix. In contrast, the damage behavior of block-shaped carbides also involved internal cracking but with a tendency to form interconnected microcracks during propagation. A crystal plasticity finite element model (CPFEM) method was further developed to study the stress/strain behavior during the deformation process, considering the crystal orientations and microstructure morphologies from the EBSD data. Those elastoplastic parameters were determined through nanoindentation experiments. Simulation results verified that blocky carbides produced a pronounced strain concentration at the interface of the carbides and matrix, thereby increasing the tendency of crack formation. This paper provides a fundamental understanding of the role of inclusions in material recycling applications. Full article
(This article belongs to the Section Metal Casting, Forming and Heat Treatment)
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16 pages, 4920 KiB  
Article
Excellent Dark/Light Dual-Mode Photoresponsive Activities Based on g-C3N4/CMCh/PVA Nanocomposite Hydrogel Using Electron Beam Radiation Method
by Jin-Yu Yang, Dong-Xu Tang, Dong-Liang Liu, Kun Liu, Xiao-Jie Yang, Yue-Sheng Li and Yi Liu
Molecules 2023, 28(22), 7544; https://doi.org/10.3390/molecules28227544 - 11 Nov 2023
Cited by 7 | Viewed by 1655
Abstract
Photocatalytic technology for inactivating bacteria in water has received much attention. In this study, we reported a dark–light dual-mode sterilized g-C3N4/chitosan/poly (vinyl alcohol) hydrogel (g-CP) prepared through freeze–thaw cycling and an in situ electron-beam radiation method. The structures and [...] Read more.
Photocatalytic technology for inactivating bacteria in water has received much attention. In this study, we reported a dark–light dual-mode sterilized g-C3N4/chitosan/poly (vinyl alcohol) hydrogel (g-CP) prepared through freeze–thaw cycling and an in situ electron-beam radiation method. The structures and morphologies of g-CP were confirmed using Fourier infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), solid ultraviolet diffuse reflectance spectroscopy (UV-vis DRS), and Brunauer–Emmett–Teller (BET). Photocatalytic degradation experiments demonstrated that 1 wt% g-CP degraded rhodamine B (RhB) up to 65.92% in 60 min. At the same time, g-CP had good antimicrobial abilities for Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) within 4 h. The shapes of g-CP were adjustable (such as bar, cylinder, and cube) and had good mechanical properties and biocompatibility. The tensile and compressive modulus of 2 wt% g-CP were 0.093 MPa and 1.61 MPa, respectively. The Cell Counting Kit-8 (CCK-8) test and Hoechst33342/PI double staining were used to prove that g-CP had good biocompatibility. It is expected to be applied to environmental sewage treatment and wound dressing in the future. Full article
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