Journal Description
Materials
Materials
is an international peer-reviewed, open access journal on materials science and engineering published semimonthly online by MDPI. The Portuguese Materials Society (SPM), Spanish Materials Society (SOCIEMAT) and Manufacturing Engineering Society (MES) are affiliated with Materials and their members receive discounts on the article processing charges.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within Scopus, SCIE (Web of Science), PubMed, PMC, Ei Compendex, CaPlus / SciFinder, Inspec, Astrophysics Data System, and other databases.
- Journal Rank: JCR - Q2 (Metallurgy & Metallurgical Engineering) / CiteScore - Q2 (Condensed Matter Physics)
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 13.9 days after submission; acceptance to publication is undertaken in 2.7 days (median values for papers published in this journal in the second half of 2023).
- Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
- Testimonials: See what our editors and authors say about Materials.
- Companion journals for Materials include: Electronic Materials and Construction Materials.
Impact Factor:
3.4 (2022);
5-Year Impact Factor:
3.8 (2022)
Latest Articles
Goldene: An Anisotropic Metallic Monolayer with Remarkable Stability and Rigidity and Low Lattice Thermal Conductivity
Materials 2024, 17(11), 2653; https://doi.org/10.3390/ma17112653 (registering DOI) - 31 May 2024
Abstract
In a recent breakthrough in the field of two-dimensional (2D) nanomaterials, the first synthesis of a single-atom-thick gold lattice of goldene has been reported through an innovative wet chemical removal of Ti3C2 from the layered Ti3AuC2.
[...] Read more.
In a recent breakthrough in the field of two-dimensional (2D) nanomaterials, the first synthesis of a single-atom-thick gold lattice of goldene has been reported through an innovative wet chemical removal of Ti3C2 from the layered Ti3AuC2. Inspired by this advancement, in this communication and for the first time, a comprehensive first-principles investigation using a combination of density functional theory (DFT) and machine learning interatomic potential (MLIP) calculations has been conducted to delve into the stability, electronic, mechanical and thermal properties of the single-layer and free-standing goldene. The presented results confirm thermal stability at 700 K as well as remarkable dynamical stability of the stress-free and strained goldene monolayer. At the ground state, the elastic modulus and tensile strength of the goldene monolayer are predicted to be over 226 and 12 GPa, respectively. Through validated MLIP-based molecular dynamics calculations, it is found that at room temperature, the goldene nanosheet can exhibit anisotropic tensile strength over 9 GPa and a low lattice thermal conductivity around 10 ± 2 W/(m.K), respectively. We finally show that the native metallic nature of the goldene monolayer stays intact under large tensile strains. The combined insights from DFT and MLIP-based results provide a comprehensive understanding of the stability, mechanical, thermal and electronic properties of goldene nanosheets.
Full article
(This article belongs to the Special Issue Thermal Management of Two-Dimensional Materials and Their Van der Waals Heterostructures)
►
Show Figures
Open AccessArticle
Inspection of Liner Wall Thinning and Interface Debonding in Bimetallic Lined Pipes Using Pulsed Eddy Current Testing
by
Weifan Chen, Xiaofeng Zhou, Baixi Liu, Zhiping Li, Zan Luo and Zhiyuan Xu
Materials 2024, 17(11), 2652; https://doi.org/10.3390/ma17112652 - 30 May 2024
Abstract
Bimetallic lined pipe (BLP) has been increasingly used in offshore and subsea oil and gas structures, but how to identify the invisible inner defects such as liner wall thinning and interface debonding is a challenge for future development. A nondestructive testing (NDT) method
[...] Read more.
Bimetallic lined pipe (BLP) has been increasingly used in offshore and subsea oil and gas structures, but how to identify the invisible inner defects such as liner wall thinning and interface debonding is a challenge for future development. A nondestructive testing (NDT) method based on pulsed eddy current testing (PECT) has been proposed to face these difficulties. The inspection of the BLP specimen (AISI1020 base tube and SS304 liner) is implemented from outside of the pipe by using a transmitter–receiver-type PECT probe consisting of two induction coils. By simplifying the BLP specimen to stratified conductive plates, the electromagnetic field interaction between the PECT probe and specimen is analytically modeled, and the probe inspection signals due to liner wall thinning and interface debonding are calculated. In order to highlight the weak response (in microvolts) from the liner, the inspection signals are subtracted by the signal, which is calculated in the case of only having a base tube, yielding differential PECT signals. The peak voltage of the differential signal is selected to characterize the liner wall thinning and interface debonding due to its distinguishable and linear variation. Experiment verification is also carried out on a double-walled specimen simulated by a combination of a Q235 casing pipe and SS304 tubes of different sizes. The experimental results basically agree with the analytical predictions. The peak value of the PECT signal has an ascending and descending variation with the increase in the remaining liner wall thickness and debonding gap, respectively, while the negative peak value shows opposite changes. The peak value exhibits a larger sensitivity than the negative peak value. The proposed method shows potential promise in practical applications for the evaluation of the inner defects in BLP lines.
Full article
(This article belongs to the Special Issue Sensing and Monitoring Technologies in Composite Materials)
Open AccessArticle
Experimental Study Based on Box–Behnken Design and Response Surface Methodology for Optimization Proportioning of Activated Lithium Slag Composite Cement-Based Cementitious Materials
by
Weixing Shao, Wenhua Zha, Xueyun Zhou and Tao Xu
Materials 2024, 17(11), 2651; https://doi.org/10.3390/ma17112651 - 30 May 2024
Abstract
Cement-based cementitious materials occupy a central position in the construction industry, but the problem of high carbon dioxide(CO2) emissions from cement production has attracted global attention. To meet this challenge, finding low-carbon alternative materials has become a top priority in the
[...] Read more.
Cement-based cementitious materials occupy a central position in the construction industry, but the problem of high carbon dioxide(CO2) emissions from cement production has attracted global attention. To meet this challenge, finding low-carbon alternative materials has become a top priority in the research of new building materials. At the same time, the problem of large amounts of lithium slag piling up needs to be solved, and resource utilization has become its potential way out. In this study, the volcanic ash activity of lithium slag was activated by composite activation means of high-temperature calcination and sodium silicate, and it was used as an alternative mix to cement. The Box–Behnken design and response surface method (BBD-RSM) was utilized to optimize the ratio of activated lithium slag composite cement-based cementitious materials, and high-performance new solid waste cementitious materials were prepared. The results show that activated lithium slag composite cementitious materials activated lithium slag exhibit excellent performance when activated lithium slag mass fraction is 7.3%, the sodium silicate dosage is 8.8%, and water–solid ratio is 0.6:1. The composite cementitious material under this ratio shows excellent performance, with fluidity 235.69 mm, gelation time 73.54 s, water evolution rate 1.123%, 3d and 28d compressive strengths, respectively, are 11.54 MPa and 22.9 MPa. Compared with ordinary Portland-cement-based cementing materials, the uniaxial compressive strength, modulus of elasticity, and tensile strength at break of activated lithium slag cementitious material solidified body were increased by 34.33%, 36.43%, and 34.98%, and the compressive deformation and tensile deformation were enhanced by 37.78% and 40%. This study not only provides a theoretical basis and experimental foundation for the preparation of new solid waste cementitious materials, but also provides a new solution for the reinforcement of crushed rock bodies in engineering practice, which is of great significance for promoting the low-carbon development of the construction industry.
Full article
(This article belongs to the Section Construction and Building Materials)
►▼
Show Figures
Figure 1
Open AccessArticle
Failure Analysis for Overall Overturning of Concrete Single-Column Pier Bridges Induced by Temperature and Overloaded Vehicles
by
Yelu Wang, Yongjun Zhou, Yuxin Xue, Changwei Yao, Kailong Wang and Xuchang Luo
Materials 2024, 17(11), 2650; https://doi.org/10.3390/ma17112650 - 30 May 2024
Abstract
Several overloaded-induced overturning incidents of girder bridges with single-column piers have occurred in recent years, resulting in significant casualties and economic losses. Temperature, in addition to overloading, may also play a role in exacerbating bridge overturning. To investigate the association between temperature and
[...] Read more.
Several overloaded-induced overturning incidents of girder bridges with single-column piers have occurred in recent years, resulting in significant casualties and economic losses. Temperature, in addition to overloading, may also play a role in exacerbating bridge overturning. To investigate the association between temperature and bridge overturning, an explicit finite element model (EFEM) of a three-span concrete curved continuous bridge considering nonlinearities was developed to simulate overall collapse. The effects of uniform and gradient temperatures on the overall overturning stability of curved and straight bridges were evaluated based on the EFEMs. Furthermore, the temperature–bridge coupling model and temperature–vehicle–bridge coupling model were utilized to examine how gradient temperature influences bridge overturning. The results show that the overall overturning collapse of a bridge follows four stages: stabilization, transition, risk and overturning. Variations in uniform temperature from −30 °C to 60 °C had a negligible effect on the ultimate vehicle weight for bridge overturning, with a variation of less than 1%. As the gradient temperature ranged from −30 °C to 60 °C, curved bridges show less than a 2% variation in ultimate vehicle weights, compared to a range of −6.1% to 11.7% for straight bridges. The torsion caused by positive gradient temperature in curved bridges can exacerbate bridge overturning, while negative gradient temperature in straight bridges can lead the girder to ‘upward warping’, facilitating girder separation from bearings. Monitoring the girder rotation angle and vertical reaction force of bearings can serve as important indicators for comparing the stability of bridges.
Full article
(This article belongs to the Topic Recent Advances in Structural Health Monitoring, 2nd Volume)
►▼
Show Figures
Figure 1
Open AccessReview
Research Progress on Helmet Liner Materials and Structural Applications
by
Xingyu Zhang, Bin Yang, Jinguo Wu, Xin Li and Ronghua Zhou
Materials 2024, 17(11), 2649; https://doi.org/10.3390/ma17112649 - 30 May 2024
Abstract
As an important part of head protection equipment, research on the material and structural application of helmet liners has always been one of the hotspots in the field of helmets. This paper first discusses common helmet liner materials, including traditional polystyrene, polyethylene, polypropylene,
[...] Read more.
As an important part of head protection equipment, research on the material and structural application of helmet liners has always been one of the hotspots in the field of helmets. This paper first discusses common helmet liner materials, including traditional polystyrene, polyethylene, polypropylene, etc., as well as newly emerging anisotropic materials, polymer nanocomposites, etc. Secondly, the design concept of the helmet liner structure is discussed, including the use of a multi-layer structure, the addition of geometric irregular bubbles to enhance the energy absorption effect, and the introduction of new manufacturing processes, such as additive manufacturing technology, to realize the preparation of complex structures. Then, the application of biomimetic structures to helmet liner design is analyzed, such as the design of helmet liner structures with more energy absorption properties based on biological tissue structures. On this basis, we propose extending the concept of bionic structural design to the fusion of plant stalks and animal skeletal structures, and combining additive manufacturing technology to significantly reduce energy loss during elastic yield energy absorption, thus developing a reusable helmet that provides a research direction for future helmet liner materials and structural applications.
Full article
(This article belongs to the Special Issue Advances in Materials Science for Engineering Applications)
►▼
Show Figures
Figure 1
Open AccessArticle
Separation of Adjacent Light Rare Earth Elements Using Silica Gel Modified with Diglycolamic Acid
by
Takeshi Ogata and Hirokazu Narita
Materials 2024, 17(11), 2648; https://doi.org/10.3390/ma17112648 - 30 May 2024
Abstract
The separation of adjacent rare earth elements (REEs) is a challenging issue due to their chemical similarity. We have investigated the separation of adjacent REEs using four types of adsorbents consisting of silica gel modified with diglycolamic acid with different functional groups at
[...] Read more.
The separation of adjacent rare earth elements (REEs) is a challenging issue due to their chemical similarity. We have investigated the separation of adjacent REEs using four types of adsorbents consisting of silica gel modified with diglycolamic acid with different functional groups at the amide position. For all the adsorbents, the adsorption ratio of REEs increased with the increase in atomic number from La to Sm and then became constant for heavy REEs. Among them, EDASiDGA, an adsorbent containing secondary and tertiary amides, showed a high separation factor for Nd/Pr of 2.8. The EDASiDGA-packed column was tested for individual recovery of Pr, Nd, and Sm. After the adsorption of these REEs from 0.10 M HCl, desorption tests were performed with 0.32 and 1.0 M HCl. As a result, Pr and Nd were eluted separately with 0.32 M HCl, and Sm was recovered with 1.0 M HCl. Since the EDASiDGA-packed column showed excellent separation of Pr/Nd/Sm without any chelating agent, it is promising for practical use.
Full article
(This article belongs to the Special Issue New Trends of Functional Materials for Wastewater Treatment Applications)
►▼
Show Figures
Graphical abstract
Open AccessArticle
Analysis of Underwater Melting Process and Leakage Plugging Performance of Phase-Change Materials
by
Shenghang Zhang, Lei Tang, Fei Li, Po Li, Yao Sima and Song Zhao
Materials 2024, 17(11), 2647; https://doi.org/10.3390/ma17112647 - 30 May 2024
Abstract
►▼
Show Figures
Leakage is a high-incidence disease of embankment dams, and efficiently addressing this disease guarantees the safe operation of dams. Underwater leakage self-priming plugging technology is a new technology that utilizes the melting and solidifying characteristics of phase-change materials and the negative pressure in
[...] Read more.
Leakage is a high-incidence disease of embankment dams, and efficiently addressing this disease guarantees the safe operation of dams. Underwater leakage self-priming plugging technology is a new technology that utilizes the melting and solidifying characteristics of phase-change materials and the negative pressure in the leakage entry area to accurately plug the leakage. However, little is yet known about the underwater melting process of phase-change materials and how their characteristics influence the plugging effect. In this study, three kinds of phase-change materials, namely, paraffin, rosin, and stearic acid, were used to conduct underwater leakage self-priming plugging tests, observe and analyze the underwater melting process, and compare the plugging effects. The results showed that the underwater melting process of phase-change materials exhibited different plugging window periods depending on their melting points, specific heat capacities, and mobilities, which were the main factors affecting their plugging effects. In the final plugging stage, paraffin had the best plugging effect, but the material strength was low; rosin had good plugging compactness, but the fluidity performance was poor, and the material effective utilization was low; stearic acid had a low melting point but dispersed easily. Therefore, a blocking material with a suitable blocking window period can be produced by adjusting the material properties accordingly for an improved blocking effect.
Full article
Figure 1
Open AccessArticle
Properties and Possibilities of Using Biochar Composites Made on the Basis of Biomass and Waste Residues Ferryferrohydrosol Sorbent
by
Katarzyna Wystalska, Mariusz Kowalczyk, Tomasz Kamizela, Małgorzata Worwąg and Magdalena Zabochnicka
Materials 2024, 17(11), 2646; https://doi.org/10.3390/ma17112646 - 30 May 2024
Abstract
►▼
Show Figures
Biochar enriched with metals has an increased potential for sorption of organic and inorganic pollutants. The aim of the research was to identify the possibility of using biochar composites produced on the basis of waste plant biomass and waste FFH (ferryferrohydrosol) containing iron
[...] Read more.
Biochar enriched with metals has an increased potential for sorption of organic and inorganic pollutants. The aim of the research was to identify the possibility of using biochar composites produced on the basis of waste plant biomass and waste FFH (ferryferrohydrosol) containing iron atoms, after CO2 capture. The composites were produced in a one-stage or two-stage pyrolysis process. Their selected properties were determined as follows: pH, ash content, C, H, N, O, specific surface area, microstructure and the presence of surface functional groups. The produced biochar and composites had different properties resulting from the production method and the additive used. The results of experiments on the removal of methylene blue (MB) from solutions allowed us to rank the adsorbents used according to the maximum dye removal value achieved as follows: BC1 (94.99%), B (84.61%), BC2 (84.09%), BC3 (83.23%) and BC4 (83.23%). In terms of maximum amoxicillin removal efficiency, the ranking is as follows: BC1 (55.49%), BC3 (23.51%), BC2 (18.13%), B (13.50%) and BC4 (5.98%). The maximum efficiency of diclofenac removal was demonstrated by adsorbents BC1 (98.71), BC3 (87.08%), BC4 (74.20%), B (36.70%) and BC2 (30.40%). The most effective removal of metals Zn, Pb and Cd from the solution was demonstrated by BC1 and BC3 composites. The final concentration of the tested metals after sorption using these composites was less than 1% of the initial concentration. The highest increase in biomass on prepared substrates was recorded for the BC5 composite. It was higher by 90% and 54% (for doses of 30 g and 15 g, respectively) in relation to the biomass growth in the soil without additives. The BC1 composite can be used in pollutant sorption processes. However, BC5 has great potential as a soil additive in crop yield and plant growth.
Full article
Graphical abstract
Open AccessArticle
Effect of Carbon Fiber and Potassium Titanate Whisker on the Mechanical and Impact Tribological Properties of Fe-Based Impregnated Diamond Bit Matrix
by
Zhiming Wang, Chengkai Guan, Wucheng Sun, Songcheng Tan, Longchen Duan and Xiaohong Fang
Materials 2024, 17(11), 2645; https://doi.org/10.3390/ma17112645 - 30 May 2024
Abstract
Various contents of carbon fibers (CFs) and potassium titanate whiskers (PTWs) were added to an Fe-based impregnated diamond bit (IDB) matrix to enhance its adaptability to percussive–rotary drilling. A series of mechanical tests were conducted successively to find the effects of the reinforcing
[...] Read more.
Various contents of carbon fibers (CFs) and potassium titanate whiskers (PTWs) were added to an Fe-based impregnated diamond bit (IDB) matrix to enhance its adaptability to percussive–rotary drilling. A series of mechanical tests were conducted successively to find the effects of the reinforcing materials on the properties of the Fe-based IDB samples. Then, the fracture surfaces of the samples were analyzed via scanning electron microscopy (SEM) and energy-dispersive spectroscopy, and the worn surfaces and abrasive debris of the samples were analyzed using a laser scanning confocal microscope and SEM. The results show that both the CF and PTW can effectively improve the hardness and bending strength of an Fe-based IDB matrix, and those parameters reached their maximum values at the additive amount of 1 wt%. However, the CF had a better enhancement effect than the PTW. Furthermore, the CF improved the impact wear resistance of the IDB matrix, with a minimum wear rate of 2.38 g/min at the additive amount of 2 wt%. However, the PTW continuously weakened the impact wear resistance of the IDB matrix with increases in its content. Moreover, the morphologies of the worn surfaces indicated that the minimum roughness of the CF-reinforced IDB matrix decreased significantly to as low as 4.91 μm, which was 46.16% lower than that without CF, whereas the minimum roughness of the PTW-reinforced samples decreased by 11.31%. Meanwhile, the abrasive debris of the CF-reinforced samples was more uniform and continuous compared to that of the PTW-reinforced samples. Overall, the appropriate addition of CF or PTWs can enhance the mechanical properties of Fe-based IDB matrices, which can be used on different formations based on their impact wear resistance.
Full article
(This article belongs to the Section Advanced Materials Characterization)
►▼
Show Figures
Figure 1
Open AccessArticle
Microstructure Evolution, Hardness, and Tribological Behaviors of Ti-50.8Ni SMA Alloy with Ultrasonic Surface Shot Peening Treatment
by
Zihan Chen, Xuanpeng Li, Yong Li, Yu Wang and Yongxin Jian
Materials 2024, 17(11), 2644; https://doi.org/10.3390/ma17112644 - 30 May 2024
Abstract
To explore a new method to improve the wear resistance of TiNi shape memory alloy (SMA), Ti-50.8Ni alloy was treated by the method of ultrasonic surface shot peening. The microstructure evolution, hardness, and tribological behaviors have been further investigated to evaluate the effect
[...] Read more.
To explore a new method to improve the wear resistance of TiNi shape memory alloy (SMA), Ti-50.8Ni alloy was treated by the method of ultrasonic surface shot peening. The microstructure evolution, hardness, and tribological behaviors have been further investigated to evaluate the effect of ultrasonic surface shot peening (USSP). The surface microstructure can be refined to some extent while the basic phase composition has little change. USSP can facilitate the martensitic transformation in the surface layer, which benefits improving the surface hardness. Additionally, the hardness of Ti-50.8Ni alloy increases first and then decreases with the increase of applied load, but the USSP-treated alloy tends to be more sensitive to load. USSP treatment can improve the wear resistance and reduce the coefficient of friction (COF) in case of a low sliding wear speed of 5 mm/s. However, the tribological properties of USSP-treated alloy are reversely worse in the case of 10 mm/s. This is mainly attributed to the combined effect of stress-induced martensite transformation and degeneration resulting from the frictional heating during the dry sliding wear process.
Full article
(This article belongs to the Special Issue Advanced Ceramic-Based Materials/Coatings for Anti-wear and Corrosion Applications)
►▼
Show Figures
Figure 1
Open AccessArticle
Realizing the Creep and Damage Effect on Masonry Panel Design Based on Reliability Analysis
by
Jung Joong Kim
Materials 2024, 17(11), 2643; https://doi.org/10.3390/ma17112643 - 30 May 2024
Abstract
In this study, a masonry panel under a high compressive stress to strength ratio is considered. The panel is modeled as a composite structure by considering a repeated unit cell of mortar and brick. Load redistributions due to creep in mortar and brick
[...] Read more.
In this study, a masonry panel under a high compressive stress to strength ratio is considered. The panel is modeled as a composite structure by considering a repeated unit cell of mortar and brick. Load redistributions due to creep in mortar and brick as composite materials are accounted for. A step-by-step in-time analysis is performed to calculate the load redistribution in the composite masonry. Time-dependent system reliability analysis of the masonry panel is performed by defining the component and system limit state functions at each time step. While the reliability index of ductile materials depends on the load level in each part of masonry, the reliability index of brittle materials depends only on the overall load. By proposing the reliability index of quasi-brittle materials being between these two reliability index bounds, the reliability index of quasi-brittle materials depends on both the load level in each part and the overall load. Using the proposed reliability index of quasi-brittle materials, partial safety factors for masonry panel design considering creep and damage are calibrated based on the Hasofer and Lind method. A design example using the proposed partial safety factor is presented.
Full article
(This article belongs to the Special Issue Defect Identification and Analysis in Building Materials: Emphasizing Concrete, Masonry, and Mortar Systems)
►▼
Show Figures
Figure 1
Open AccessArticle
Effect of Cyclic Ice Plug Deformation on Microstructure and Mechanical Behaviors of Nuclear-Grade Low-Carbon Tubular Steel
by
Minglei Hu, Wei Zhang, Ke Xu, Bin Hu, Dongsheng Li, Lan Wang, Rencai Liu and Xiaohua Zhao
Materials 2024, 17(11), 2642; https://doi.org/10.3390/ma17112642 - 30 May 2024
Abstract
This study subjected nuclear-grade 20# pipeline steel to cyclic freeze–thaw ice plugging tests, simulating the plastic deformation experienced by pipes during ice plug removal procedures. Subsequently, the dislocation morphology and mechanical properties of the specimens post cyclic ice plugging were examined. The cyclic
[...] Read more.
This study subjected nuclear-grade 20# pipeline steel to cyclic freeze–thaw ice plugging tests, simulating the plastic deformation experienced by pipes during ice plug removal procedures. Subsequently, the dislocation morphology and mechanical properties of the specimens post cyclic ice plugging were examined. The cyclic ice plugging process led to an increase in the dislocation density within the specimens. After 20 and 40 cycles of ice plugging, the internal dislocation structures evolved from individual dislocation lines and dislocation tangles to high-density dislocation walls and dislocation cells. These high-density dislocation walls and cells hindered dislocation motion, giving rise to strain hardening phenomena, thereby resulting in increased strength and hardness of the specimens with an increasing number of ice plugging cycles. In addition, a large stress field was generated around the dislocation buildup, which reduced the pipe material’s plastic toughness. The findings elucidate the effects of cyclic ice plugging on the microstructure and properties of nuclear-grade 20# pipeline steel, aiming to provide a theoretical basis for the safe and stable application of ice plugging technology in nuclear piping systems.
Full article
(This article belongs to the Special Issue Advanced Steel Materials: Recrystallization, Phase Transformation and Microstructure Analysis)
►▼
Show Figures
Figure 1
Open AccessArticle
Enhancing Mesopore Volume and Thermal Insulation of Silica Aerogel via Ambient Pressure Drying-Assisted Foaming Method
by
Jinjing Guo, Kaiqiang Luo, Wenqi Zou, Jun Xu and Baohua Guo
Materials 2024, 17(11), 2641; https://doi.org/10.3390/ma17112641 - 30 May 2024
Abstract
Ambient pressure drying (APD) of silica aerogels has emerged as an attractive method adapting to large-scale production. Spring-back is a unique phenomenon during APD of silica aerogels with volume expansion after its shrinkage under capillary force. We attribute the intense spring-back at elevated
[...] Read more.
Ambient pressure drying (APD) of silica aerogels has emerged as an attractive method adapting to large-scale production. Spring-back is a unique phenomenon during APD of silica aerogels with volume expansion after its shrinkage under capillary force. We attribute the intense spring-back at elevated drying temperatures to a dense structure formed on the surface and the formation of positive internal pressure. Furthermore, an APD-assisted foaming method with an in situ introduction of NH4HCO3 was proposed. NH4HCO3 decomposing at drying temperatures hastened the emergence of positive pressure, thereby increasing the expansion volume. Compared to the previous method, the porosity of silica aerogel increased from 82.2% to 92.6%, and mesopore volume from 1.79 cm3 g−1 to 4.54 cm3 g−1. By adjusting the amount of the silicon source, silica aerogels prepared by the APD-assisted foaming method generated higher volume expansion and lower thermal conductivity. After calcination to remove undecomposed ammonium salts, the hydrophobic silica aerogel with a density of 0.112 g cm−3 reached a mesopore volume of 5.07 cm3 g−1 and a thermal conductivity of 18.9 mW m−1·K−1. This strategy not only improves the thermal insulation properties, but also offers a significant advancement in tailoring silica aerogels with specific porosity and mesopore volume for various applications.
Full article
(This article belongs to the Special Issue The 15th Anniversary of Materials—Recent Advances in Materials Chemistry)
►▼
Show Figures
Figure 1
Open AccessArticle
Effects of Mixing Techniques and Material Compositions on the Compressive Strength and Thermal Conductivity of Ultra-Lightweight Foam Concrete
by
Tongyu Xu and Harald Garrecht
Materials 2024, 17(11), 2640; https://doi.org/10.3390/ma17112640 - 30 May 2024
Abstract
The research focuses on ultra-lightweight foam concrete with a dry density below 200 kg/m3, primarily used as insulation material. Factors that may affect material properties are categorized into mixing techniques and material composition, and experimental investigations were conducted on the impact
[...] Read more.
The research focuses on ultra-lightweight foam concrete with a dry density below 200 kg/m3, primarily used as insulation material. Factors that may affect material properties are categorized into mixing techniques and material composition, and experimental investigations were conducted on the impact of these factors on the rheological properties of cement slurry, density at different time intervals, compressive strength, and thermal conductivity of foam concrete samples. The experimental results indicate the influence of mixing speed and mixing duration on the instrument during the cement slurry production and mixing process with foam. Additionally, variations in foam concrete sample properties are observed due to the water-to-cement ratio, foam content, and foam density in the selected material compositions. By analyzing the material density at different time intervals, the relationship between the ambient air trapped during the mixing process and the viscosity of the material can be indirectly observed. This analysis can also reveal the correlation between the unplanned air content and the properties of the material.
Full article
(This article belongs to the Section Construction and Building Materials)
►▼
Show Figures
Figure 1
Open AccessArticle
Influence of Pre- and Post-Contouring Strategies to Downskin Sloped Surfaces in Laser Powder-Bed Fusion (L-PBF) Additive Manufacturing
by
Nismath Valiyakath Vadakkan Habeeb, Rabiul Islam and Kevin Chou
Materials 2024, 17(11), 2639; https://doi.org/10.3390/ma17112639 - 30 May 2024
Abstract
Among various metal additive manufacturing (AM) technologies, L-PBF is known for fabricating intricate components. However, due to step edges and powder particle attachments, attaining a good surface finish is challenging, especially on downskin surfaces. Contour scanning has potential to improve surface quality because
[...] Read more.
Among various metal additive manufacturing (AM) technologies, L-PBF is known for fabricating intricate components. However, due to step edges and powder particle attachments, attaining a good surface finish is challenging, especially on downskin surfaces. Contour scanning has potential to improve surface quality because such scanning may dominate the surface formation of sloped features. This study evaluates the effects of pre- and post-contouring strategies on the sloped downskin surfaces fabricated using a commercial L-PBF system with Ti6Al4V powder. L-PBF parts printed at inclination angles 30°, 45° and 60° were investigated. A double-contouring approach with varying processing conditions was employed and surface characteristics were analyzed using data acquired by white light interferometry. The average surface roughness, Sa, surface skewness, Ssk, and percentage area of powder particles attached onto surfaces were statistically evaluated. The lowest Sa obtained for pre- and post-contoured samples is 14.08 µm and 18.88 µm, respectively. For both strategies, the combination of a low laser power and a high scan speed on the interface of downskin surface and underneath powder results in smoother surfaces. However, while comparing both strategies, pre-contouring gives better surface finish for samples built at similar processing conditions, with a difference of nearly 5 µm in Sa.
Full article
(This article belongs to the Special Issue Design, Optimization, Simulation, and Defect Detection for Additive Manufacturing)
►▼
Show Figures
Figure 1
Open AccessArticle
A Top-Down Approach to the Fabrication of Flame-Retardant Wood Aerogel with In Situ-Synthesized Borax and Zinc Borate
by
Mingzeng Lin, Xiangkun Guo, Yinchao Xu, Xuejin Zhang and Donghao Hu
Materials 2024, 17(11), 2638; https://doi.org/10.3390/ma17112638 - 30 May 2024
Abstract
►▼
Show Figures
In this study, a top-down approach was employed for the fabrication of flame-retardant wood aerogels. The process involved the removal of lignin and the removal of hemicellulose utilizing NaOH concomitantly with the incorporation of ZnO and urea. Subsequently, an in situ reaction with
[...] Read more.
In this study, a top-down approach was employed for the fabrication of flame-retardant wood aerogels. The process involved the removal of lignin and the removal of hemicellulose utilizing NaOH concomitantly with the incorporation of ZnO and urea. Subsequently, an in situ reaction with boric acid was conducted to prepare flame-retardant wood aerogels. The morphology, chemical composition, thermal stability, and flame retardancy of the samples were studied. The results show that the NaOH treatment transformed the wood into a layered structure, and flame-retardant particles were uniformly distributed on the surface of the aerogel. The peak heat release rate (PHRR) and total heat release (THR) of the flame-retardant aerogel were significantly reduced compared with the control samples. Meanwhile, its vertical burning test (UL-94) rating reached the V-0 level, and the Limiting Oxygen Index (LOI) could exceed 90%. The flame-retardant wood aerogel exhibited excellent flame retardancy and self-extinguishing properties.
Full article
Figure 1
Open AccessArticle
Enhanced Hydrogen Generation through Low-Temperature Plasma Treatment of Waste Aluminum for Hydrolysis Reaction
by
Marius Urbonavicius, Sarunas Varnagiris, Ainars Knoks, Ansis Mezulis, Janis Kleperis, Christiaan Richter, Rauan Meirbekova, Gudmundur Gunnarsson and Darius Milcius
Materials 2024, 17(11), 2637; https://doi.org/10.3390/ma17112637 - 29 May 2024
Abstract
This study investigates the low-temperature hydrogen plasma treatment approach for the improvement of hydrogen generation through waste aluminum (Al) reactions with water and electricity generation via proton-exchange membrane fuel cell (PEM FC). Waste Al scraps were subjected to ball milling and treated using
[...] Read more.
This study investigates the low-temperature hydrogen plasma treatment approach for the improvement of hydrogen generation through waste aluminum (Al) reactions with water and electricity generation via proton-exchange membrane fuel cell (PEM FC). Waste Al scraps were subjected to ball milling and treated using two different low-temperature plasma regimes: Diode and magnetron-initiated plasma treatment. Hydrolysis experiments were conducted using powders with different treatments, varying molarities, and reaction temperatures to assess hydrogen generation, reaction kinetics, and activation energy. The results indicate that magnetron-initiated plasma treatment significantly enhances the hydrolysis reaction kinetics compared to untreated powders or those treated with diode-generated plasma. Analysis of chemical bonds revealed that magnetron-initiated hydrogen plasma treatment takes advantage by promoting a dual procedure: Surface cleaning and Al nanocluster deposition on top of Al powders. Moreover, it was modeled that such H2 plasma could penetrate up to 150 Å depth. Meanwhile, electricity generation tests demonstrate that only 0.2 g of treated Al powder can generate approximately 1 V for over 300 s under a constant 2.5 Ω load and 1.5 V for 2700 s with a spinning fan.
Full article
(This article belongs to the Special Issue Advanced Designs of Materials, Machines and Processes in a Circular Economy)
Open AccessArticle
Research on Resource Recovery and Disposal of Copper-Containing Sludge
by
Jinao Yu and Yongmin Zhou
Materials 2024, 17(11), 2636; https://doi.org/10.3390/ma17112636 - 29 May 2024
Abstract
Copper-containing sludge is a common by-product of industrial activities, particularly electroplating and metal processing. This type of sludge contains high concentrations of heavy metals such as copper, which can pose a potential threat to the environment. Therefore, its treatment and disposal require special
[...] Read more.
Copper-containing sludge is a common by-product of industrial activities, particularly electroplating and metal processing. This type of sludge contains high concentrations of heavy metals such as copper, which can pose a potential threat to the environment. Therefore, its treatment and disposal require special attention. Due to its efficient mass and heat transfer characteristics, the suspended state technology has shown significant potential for application in a number of key processes, including the drying, decomposition, and reduction of copper-containing sludge. This paper presents an in-depth analysis of the current status of the application of the suspended state technology in the treatment of copper-containing sludge. Based on this analysis, a device for the treatment of copper-containing sludge in the suspended state was designed, through which the characteristics of copper-containing sludge in the oxidative decomposition and reduction phases are investigated. The research objects were gas concentration, temperature, contact state, and particle size time. Orthogonal experiments were initially employed to investigate the relationship between the influencing factors and the conversion rate of copper oxides. This was followed by a single-factor influence study, which led to the determination of the optimal process parameters for the decomposition experiments of the Cu-containing sludge in an oxidizing atmosphere. The 100 μm Cu-containing sludge was reacted with 10% O2 gas at a flow rate of 1 m/s for 3 min under the condition of 900 °C. The process parameters were then determined as follows: The research objects were gas concentration, temperature, contact state, and particle size time. Orthogonal experiments were employed to investigate the relationship between the influencing factors and the copper conversion rate. This was followed by a single-factor influence study, which determined the optimal process parameters for the copper-containing sludge reduction experiments. The 200 μm copper-containing sludge was reacted for 5 min at a flow rate of 7% carbon monoxide at a flow rate of 1.5 m/s under the condition of 800 °C.
Full article
(This article belongs to the Topic Technologies for Wastewater and Sludge Treatment)
Open AccessArticle
Effects of Misalignment of c-axis on the Properties of Hydrogenation–Disproportionation–Desorption–Recombination Particles
by
Xuhua Wang, Zilong Wang, Yuanfei Yang, Ningtao Quan, Zhongkai Wang, Haijun Peng, Hongbin Zhang, Xiaojun Sun, Shuai Cui, Dunbo Yu and Yang Luo
Materials 2024, 17(11), 2635; https://doi.org/10.3390/ma17112635 - 29 May 2024
Abstract
Hydrogenation–Disproportionation–Desorption–Recombination (HDDR) Nd2Fe14B particles have excellent magnetic properties, but the magnetic properties of powder are not uniform across different particle sizes. The remanence and maximum magnetic energy products of samples with a particle size of 120 μm are 14.0
[...] Read more.
Hydrogenation–Disproportionation–Desorption–Recombination (HDDR) Nd2Fe14B particles have excellent magnetic properties, but the magnetic properties of powder are not uniform across different particle sizes. The remanence and maximum magnetic energy products of samples with a particle size of 120 μm are 14.0 kGs and 41.35 MGOe, while the products of samples with a particle size of 60 μm are only 13.3 kGs and 36.31 MGOe. The macroscopic morphology of HDDR Nd2Fe14B particles and the gradient distribution of microstructures in different micro-regions were observed. By modifying the macroscopic morphology of the particles, the poorly oriented clusters on the surface of the particles were precisely eliminated, and the remanence and maximum magnetic energy products of the particles increased to 14.5 kGs and 45 MGOe, respectively. Compared with the original particles, the samples after mechanical grinding had better grain arrangement. The effects of the nanocrystalline c-axis and field misalignment angle θ on the magnetic properties of HDDR Nd2Fe14B particles were investigated through micromagnetic simulation. The targeted removal of macroscopic defects on the particle surface contributed to a 3.6% increase in remanence and an 8.8% increase in the maximum magnetic energy product, offering a promising approach to enhance the microstructure of high-performance HDDR Nd2Fe14B particles.
Full article
Open AccessReview
The Utilization of Shape Memory Alloy as a Reinforcing Material in Building Structures: A Review
by
Lidan Xu, Miaomiao Zhu, Jitao Zhao, Ming Chen and Mingfang Shi
Materials 2024, 17(11), 2634; https://doi.org/10.3390/ma17112634 - 29 May 2024
Abstract
Shape memory alloy (SMA), a type of smart material, is widely used in the design of reinforcement and repair, isolation, and shock absorption of building structures because of its outstanding characteristics, such as the shape memory effect (SME), superelasticity (SE), and high damping.
[...] Read more.
Shape memory alloy (SMA), a type of smart material, is widely used in the design of reinforcement and repair, isolation, and shock absorption of building structures because of its outstanding characteristics, such as the shape memory effect (SME), superelasticity (SE), and high damping. It not only improves the bearing capacity, ductility, and mechanical properties of the structural components of buildings but can also effectively slow down the strong response of engineering structures under the effect of an earthquake. It plays a key role in energy dissipation and shock absorption as well as sustainable development. To promote the application of SMA in building structures, this paper summarizes the research on the use of SMA as a reinforcing material in building structures, including work related to SMA material characteristics and types, SMA-reinforced structural components, and SMA isolation devices. In addition, the shortcomings of SMA applications in building structures are analyzed, and valuable suggestions for future research methods are put forward. SMA has been applied to engineering practice in the form of embedded and external reinforcement, which shows that it has broad application prospects in future buildings.
Full article
(This article belongs to the Special Issue Modeling and Design Based on Shape Memory Behavior)
►▼
Show Figures
Figure 1
Journal Menu
► ▼ Journal Menu-
- Materials Home
- Aims & Scope
- Editorial Board
- Reviewer Board
- Topical Advisory Panel
- Instructions for Authors
- Special Issues
- Topics
- Sections & Collections
- Article Processing Charge
- Indexing & Archiving
- Editor’s Choice Articles
- Most Cited & Viewed
- Journal Statistics
- Journal History
- Journal Awards
- Society Collaborations
- Conferences
- Editorial Office
Journal Browser
► ▼ Journal BrowserHighly Accessed Articles
Latest Books
E-Mail Alert
News
Topics
Topic in
Energies, Materials, Processes, Solar, Sustainability
Solar Thermal Energy and Photovoltaic Systems, 2nd Volume
Topic Editors: Pedro Dinis Gaspar, Pedro Dinho da Silva, Luís C. PiresDeadline: 31 May 2024
Topic in
Bioengineering, JMMP, Materials, Micromachines, Polymers
Advances in Filament Engineering for Biomaterials
Topic Editors: Ming-Wei Chang, Zeeshan Ahmad, Hui-Min David WangDeadline: 30 June 2024
Topic in
Catalysts, Coatings, Crystals, Energies, Materials, Nanomaterials
Interfacial Bonding Design and Applications in Structural and Functional Materials
Topic Editors: Junlei Qi, Pengcheng Wang, Yaotian YanDeadline: 20 July 2024
Topic in
Coatings, CMD, Materials, Metals, Molecules
Corrosion and Protection of Metallic Materials, 2nd Edition
Topic Editors: Sebastian Feliú, Jr., Federico R. García-Galván, Lucien VelevaDeadline: 31 July 2024
Conferences
Special Issues
Special Issue in
Materials
Surface Inspection and Description in Metrology and Tribology (Second Volume)
Guest Editors: Chris Brown, Pawel Pawlus, Rafał Reizer, Alejandro Pereira, Michal Wieczorowski, Maxence BigerelleDeadline: 31 May 2024
Special Issue in
Materials
Structural Health Monitoring of Polymer Composites
Guest Editors: Patricia Krawczak, Salim ChakiDeadline: 10 June 2024
Special Issue in
Materials
Thermal Behavior of Polymeric and Other Advanced Materials
Guest Editors: Małgorzata Maciejewska, Magdalena RogulskaDeadline: 30 June 2024
Special Issue in
Materials
Advances in Nanomaterials and Molecules and Their Applications on Environment Recovery and Release Systems
Guest Editors: Fernando Gomes de Souza Junior, Diganta Bhusan DasDeadline: 20 July 2024
Topical Collections
Topical Collection in
Materials
3D Printing in Medicine and Biomedical Engineering
Collection Editor: Filip Górski
Topical Collection in
Materials
Catalysts: Preparation, Catalytic Performance and Catalytic Reaction
Collection Editors: Gina Pecchi, Cristian H. Campos
Topical Collection in
Materials
Microstructure and Corrosion Behavior of Advanced Alloys
Collection Editor: Marián Palcut
Topical Collection in
Materials
Manufacturing Engineering and Mechanical Properties of Composite Materials
Collection Editor: Aminul Islam