Materials Research Express最新文献

{"title":"Comprehensive characterization of spathe fibres extracted from Cocos nucifera: physical, chemical, mechanical, thermal, and acoustic properties for insulation applications","authors":"Muralikrishnan Alagarsamy, P Pitchipoo and Senthil Kumar","doi":"10.1088/2053-1591/ad5f08","DOIUrl":"https://doi.org/10.1088/2053-1591/ad5f08","url":null,"abstract":"In this study, a complete characterization of fibres extracted from the spathe of the Cocos nucifera plant and the properties of spathe fibres are compared with coir fibre extracted from the outer husk of coconut. Coconut spathe fibre is available as bio waste in bulk. The spathe fibres were carefully extracted, pre-treated with NaOH, and porous nonwoven fibre mat were prepared. The physical properties of spathe fibres were measured as per ASTM standards, and average length, diameter, and linear density were found to be 222 mm, 330 μm, and 58.85 tex, respectively. Chemical compositions, XRD analysis, single fibre tensile strength and elongation, morphological analysis by scanning electron microscopy (SEM), and thermal characterization by TGA were also carried out. Spathe fibres treated with NaOH resulted in a 5% reduction in crystallinity index and more surface unevenness and pits. Developing acoustic insulation fibre mat from spathe fibre is a first-of-its-kind study. The sound absorption coefficient of the spathe fibre mat obtained from the impedance tube tester brings out a maximum absorption coefficient of 0.950 at 3150 Hz. The results were compared with coir fibre extracted from the outer husk of coconut and concluded that coconut spathe fibre is a suitable alternative for synthetic and other natural fibres.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"11 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141612895","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}

{"title":"Effect of aging on the structure and mechanical properties of austenite stainless steel N50 alloyed with nitrogen, niobium and vanadium","authors":"Sarkis Muradian, Mingzhou Liu, Yan Sun","doi":"10.1088/2053-1591/ad5cd7","DOIUrl":"https://doi.org/10.1088/2053-1591/ad5cd7","url":null,"abstract":"In this study, the austenitic, corrosion-resistant N50 steel alloyed with different nitrogen, niobium and vanadium content was investigated. This steel is used in the production of high-strength, cryogenic pipes. The production process for these pipes involves aging at 650 °C–665 °C for 50–100 h. Therefore, steels were examined in their as-delivered state, after aging at 650 °C, 100 h and after solid solution heat treatment. The structure of the steel was analyzed using optical and scanning microscopy, tensile and impact strength tests were conducted at room temperature and at −196 °C. It was found that the total volume fraction of the precipitated phase after aging is more dependent on the total concentration of nitride-forming elements—Nb and V, than on nitrogen. Aging does not affect the basic operational properties at room temperature, but it can significantly affect toughness at −196 °C.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"19 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141571026","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}

{"title":"Microstructures evolution, texture characteristics and mechanical properties of extruded Mg-9Gd-3Nd-1Zn-1Sn-0.5Zr alloy","authors":"Xinna Liu, Zehua Yan and Wei Zhang","doi":"10.1088/2053-1591/ad5e39","DOIUrl":"https://doi.org/10.1088/2053-1591/ad5e39","url":null,"abstract":"In this study, a comprehensive investigation was conducted to explore the microstructural evolution, texture characteristics, and mechanical properties of extruded Mg-9Gd-3Nd-1Zn-1Sn-0.5Zr alloys with varying extrusion ratios (ERs). Moreover, the high-temperature mechanical properties of the alloy and analyzed the corresponding fracture mechanisms were investigated. The findings unveiled a refinement in grain size and an improvement in homogeneity with increasing ER. Such refinement coincided with the disruption of coarse Mg5(Gd, Nd, Zn) eutectic phases, facilitating dynamic recrystallization. As a result, the extruded alloy manifested small grains, significant orientation difference in grain boundaries, and a weakened texture. In particular, the average grain size in the extrusion direction (ED) diminished to 13.29 μm (ER4), 9.62 μm (ER16), and 4.05 μm (ER25). And the ED texture of the ER4 alloy featured a strong (0001) basal bimodal pattern, whereas the ER16 and ER25 alloys showcased a random texture. Furthermore, the ER25 alloy displayed notable work hardening at temperatures of 200 °C or below, exerting a significant influence on its stress–strain curve. The ultimate tensile strength (UTS) of the alloy remained consistently above 275.09 MPa, demonstrating ductile fracture characteristics characterized by numerous dimples at temperatures of 200 °C or higher. The study identified the second phase as the primary contributor to enhancing the high-temperature tensile characteristics of the alloy. In summary, this research developed a unique high-strength Mg-9Gd-3Nd-1Zn-1Sn-0.5Zr alloy characterized by fine grain and texture strengthening. The alloy exhibited remarkable stability at temperatures of 250 °C or lower, making it a promising candidate for applications in high-temperature applications.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"17 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141586192","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}

{"title":"Unveiling the combined influence of higher molecular weight polyethylene glycol and superplasticizer chemistry on fresh, mechanical, and microstructural performance of internally cured mortar","authors":"Kastro Kiran V, Dhanya Sathyan","doi":"10.1088/2053-1591/ad5c30","DOIUrl":"https://doi.org/10.1088/2053-1591/ad5c30","url":null,"abstract":"The limitations of conventional water curing in tall structures and arid regions necessitate alternative hydration strategies. Use of internal curing agents in high strength concrete can effectively mitigate evaporation and promote enhanced cement hydration in the concrete. However, because the superplasticizer is a required component in high strength concrete, compatibility of the internal curing agent with superplasticizer needs to be investigated. This study investigates the efficacy of internal curing (IC) using polyethylene glycols (PEGs)–PEG 4000 and PEG 6000, in conjunction with superplasticizer from two different families, polycarboxylate ether (PCE) and sulphonated naphthalene formaldehyde (SNF) in mortar mixes. A total of ten mixes were prepared for which samples from each mix were exposed to standard water curing, room curing, and internal curing. The research outcomes reveal a novel application of PEG 6000 and PEG 4000 in conjunction with PCE-based superplasticizers at optimized dosages, presenting a promising avenue for direct implementation in mortar mixes to meet both mechanical and durability prerequisites. Optimized IC mortar mixes displayed comparable or superior mechanical and durability performance to conventionally cured counterparts. This study demonstrates the potential of PEG 6000-PCE combinations as IC agents for improved fresh and hardened properties, offering a viable alternative for challenging construction environments. Further research is warranted to explore the long-term performance and economic feasibility of IC mortars in large-scale projects.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"5 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141571072","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}

{"title":"Microstructure and performance of carbon fiber reinforced aluminum matrix composites with molybdenum carbide coating on carbon fibers","authors":"Tingting Liu, Xinbo He, Lin Zhang, Shubin Ren, Xuanhui Qu","doi":"10.1088/2053-1591/ad5cd4","DOIUrl":"https://doi.org/10.1088/2053-1591/ad5cd4","url":null,"abstract":"In this work, a molybdenum carbide coating on the surface of short carbon fibers prepared using molten salt method was proposed to ameliorate the interfacial bonding and improve the performance of carbon fiber/Al composites. The carbon fiber/Al composites were produced using vacuum hot pressing. The characteristics of molybdenum carbide coating were analyzed. Besides, the microstructures, bending strength and thermal properties of the carbon fiber/Al composites were explored. Furthermore, the interfacial thermal resistance of the composites was investigated in relation to theoretical evaluations derived from the combined Maxwell-Garnett effective medium approach and acoustic mismatch model schemes. The results indicated that a homogeneous Mo₂C coating with a thickness of 0.5 <italic toggle=\"yes\">μ</italic>m was obtained by proper molar ratio of carbon fibers, MoO₃ and chloride salts mixture and heated at 1000 °C for 60 min. The Mo₂C coating greatly enhanced the bond between the aluminum matrix and carbon fiber, leading to improvements in the densification behavior and bending strength of the coated composites. The enhanced thermal properties including improved thermal conductivity and reduced coefficient of thermal expansion (CTE) were also achieved by the Mo₂C coating. The in-plane thermal conductivity of 60 vol.% Mo₂C-coated carbon fiber/Al composite was 221 W·m⁻¹·K⁻¹ enhanced by 92% compared to that of uncoated composite and the CTE was 6.0 × 10^–6 K⁻¹ which was suitable for electronic packaging materials.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"43 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141571073","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}

{"title":"Comparison of mathematical and supervised machine-learning models for ductile-to-brittle transition in bcc alloys","authors":"Parag M Ahmedabadi","doi":"10.1088/2053-1591/ad5cd8","DOIUrl":"https://doi.org/10.1088/2053-1591/ad5cd8","url":null,"abstract":"This study focuses on modelling Ductile-to-Brittle Transition (DBT) curves using various mathematical and supervised machine learning models. Charpy impact energy values are converted to normalized energy values to account for reductions in upper-shelf energy. The research introduces a saturation parameter in mathematical models to capture these variations and examines the influence of alloying elements, microstructure, and neutron irradiation on DBT behaviour in nuclear structural materials. Detailed analyses reveal how fitting parameters vary with these factors and demonstrate that mathematical models’ fitting parameters generally align with observed DBT curve trends. The predictive capabilities of these mathematical models are also compared with those of supervised machine learning models, highlighting the strengths and limitations of each approach in modelling DBT behaviour. An explainable approach is used for interpretation of machine learning models and it is shown that this approach can be effectively used for the influence of various independent parameters on impact energy.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"40 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141571074","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}

{"title":"Tunable optical properties of graphene wrapped ZnO@Ag spherical core-shell nanoparticles","authors":"Belayneh Mesfin Ali","doi":"10.1088/2053-1591/ad5cda","DOIUrl":"https://doi.org/10.1088/2053-1591/ad5cda","url":null,"abstract":"In this paper, we studied theoretically and numerically the material’s response to incident electromagnetic wave of graphene wrapped zinc-oxide/silver (g − ZnO@Ag) core–shell spherical nanoparticles embedded in a dielectric host matrix. As the nanoparticles size is ∼30 nm, a size much smaller than the wavelength of light, the quasi-static approximation is utilized to obtain analytical expressions for the electric polarizability and the corresponding extinction cross-section. It is found that the spectra of the extinction cross-section of g − ZnO@Ag nanoparticles exhibit two sets of localized surface resonance peaks in the visible and near infra-red (NIR) spectral regions. The first set of peaks observed below ∼900 nm are due to the coupling of the energy gap of the ZnO core with the local surface plasmon resonances of Ag shell, and the second set of graphene-assisted narrow peaks located in the NIR region (above ∼900 nm) are attributed to the plasmons excited at the Ag/graphene interface. It is found that the intensity of the extinction cross-section as well as the positions of the resonance wavelengths are interesting that the graphene-assisted narrow peaks are strongly dependent on the number of layers (Ng) and the chemical potential (μ) of graphene. It means that the response of ZnO@Ag core–shell nanoparticles to electromagnetic fields are greatly enhanced when it is wrapped with graphene and can also be tuned in the therapeutic NIR spectral region by varying Ng and μ. The results may be used for possible application in the medical fields, especially for cancer detection and drug delivery.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"61 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141548713","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}

{"title":"Seismic performance analysis and control method of composite coupled shear wall with steel plate-fiber reinforced concrete coupling beams","authors":"Yangyang Xia, Chenming Shen, Yuanyuan Xia, Haizeng Yang, Youchun Wang and Jianbo Tian","doi":"10.1088/2053-1591/ad592e","DOIUrl":"https://doi.org/10.1088/2053-1591/ad592e","url":null,"abstract":"This paper based on the study of steel plate-fiber reinforced concrete coupling beam components, designs a basic model of composite coupled shear walls with steel plate-fiber reinforced concrete coupling beams. The seismic performance of this model was numerically simulated using the ABAQUS finite element software, analyzing the stress distribution of various parts and the development pattern of plastic hinges in the structure. It also examines how factors such as axial compression ratio, coupling beam cross-sectional dimensions, single-sided wall limb aspect ratio, and total floor height affect the seismic performance of this type of coupled shear wall, providing a reasonable range for axial compression ratios and coupling ratios for composite coupled shear walls with steel plate-fiber reinforced concrete coupling beams. Based on the obtained reasonable axial compression ratio and coupling ratio, and using the analytical solution of the continuum method, a method for controlling the seismic performance of coupled shear wall structures was proposed. Results show that the composite coupled shear walls with steel plate-fiber reinforced concrete coupling beams exhibit high load-bearing capacity and lateral stiffness under inverted triangular horizontal loads, with good displacement ductility and strong energy dissipation capability, making it an excellent seismic performance coupled shear wall system. As the axial compression ratio increases, the displacement corresponding to the yield point and peak point of the structure gradually decreases, and the displacement ductility coefficient shows a trend of first increasing and then decreasing; it is recommended that when designing steel plate-fiber reinforced concrete coupling beam-coupled shear walls, the axial compression ratio should not exceed 0.3. Numerical analysis of coupling ratio-related parameters indicates that in high-intensity seismic design areas, the range of coupling ratios should be between 45% and 60%.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"32 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141548629","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}

{"title":"An EPR study of point defects in zinc oxide thin films","authors":"Jinan Fadel Mohammad Ali Heydari and Mehmet Hikmet Yükselici","doi":"10.1088/2053-1591/ad5a6a","DOIUrl":"https://doi.org/10.1088/2053-1591/ad5a6a","url":null,"abstract":"We studied ZnO thin films deposited on glass slides by thermal evaporation in vacuum followed by heat treatment in open air or Ar flow. The samples were characterized using x-ray diffraction, Raman scattering, photoluminescence (PL), and electron paramagnetic resonance (EPR) spectroscopy. We observed a broad PL band in the visible region at spectral positions of 504 and 560 nm and a low-intensity band in the UV region at 390 nm. The EPR spectra display a clear first derivative structure at at temperatures below 200 K. The PL spectrum shows red-shifted valence to conduction band emission due to electron hole recombination through shallow surface states. We found an activation energy of Ea = 4.2 meV using the Arrhenius plot and estimated concentrations of paramagnetic defects and spin–spin relaxation time constants of 1016 m−3 and 10–14 s, respectively.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"128 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141516860","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}

{"title":"Impact of cyclic thermal shocks on the electrochemical and tribological properties of Fe-based amorphous coating","authors":"Muhammad Yasir, Muhammad Arslan Hafeez, Muhammad Atiq Ur Rehman and Cheng Zhang","doi":"10.1088/2053-1591/ad594e","DOIUrl":"https://doi.org/10.1088/2053-1591/ad594e","url":null,"abstract":"Fe-based amorphous coatings hold immense potential for marine industries due to their remarkable properties, including high hardness, exceptional corrosion resistance, and outstanding wear resistance. However, their performance under thermal shock conditions, particularly in high-temperature applications, remains a topic requiring further investigation. In this work, a Fe-based amorphous coating with a composition of Fe48Mo14Cr15Y2C15B6 was successfully developed using High-velocity oxygen fuel thermal spraying. To assess the thermal shock resistance of the amorphous coating, we subjected them to thermal cycles at 300 °C for 150 times, followed by cooling in two different mediums: saltwater quenching and air cooling. The results revealed that the coating maintained excellent contact with the substrate and preserved mainly amorphous structure both in the as-sprayed condition and after thermal shocks. Interestingly, the differential scanning calorimetry (DSC) results indicated that the air-cooled samples exhibited greater structural relaxation and crystallization compared to the brine-quenched samples. This microstructure changes in the air-cooled samples resulted in inferior mechanical properties, such as wear resistance and hardness, compared to the brine-quenched and as-sprayed samples.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"56 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141531073","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}