Improved Material Properties Research Articles

Research Progress on the Relationship Between Microstructure and Properties of AISI 321 Stainless Steel

AISI 321 stainless steel is widely used in chemical pipelines and nuclear power, prompting research on its high-temperature performance and corrosion resistance. This review focuses on the effects of alloy elements, second-phase particle formation, and heat treatment processes on the microstructure and properties of AISI 321 stainless steel. Fine tuning of alloying elements can affect the mode and effect of dynamic recrystallization, altering the high-temperature flow deformation of AISI 321 stainless steel. In order to achieve phase equilibrium, the relationship between corrosion resistance and high-temperature creep behavior and high-temperature mechanical behavior in the presence of second-phase particles was also analyzed. This review outlines the basic heat treatment procedures for improving material properties, providing a new perspective for solution treatment and improving corrosion resistance. In addition, the latest research progress on other factors affecting the high-temperature performance of AISI 321, such as coatings, was briefly introduced.

Effect of B/Pb ion replacement in B2O3-PbO-SiO2 glasses: Structural, thermal, optical and electrical properties

Due to its easy manufacturing process and outstanding physical and chemical characteristics, boron lead silicate glass is widely used in electronic packaging, optical fields, and sensor technology. Herein, new glass samples with different proportions of B2O3/PbO are prepared by a combined melting and annealing process. The glasses undergo structural and thermal characterization to investigate its composition, thermal behavior, optical properties, and dielectric properties. The results show that the glass structure changes gradually as [SiO4] and [PbO4] units were replaced by [BO3] units with increasing B2O3 content. This transformation has an impact on coefficient of thermal expansion and characteristic temperature of the glass. Additionally, it is observed that alterations in structure resulted in a decrease in both optical band gap as well as dielectric constant and loss. These findings provide insights into how variations in the B2O3/PbO ratio influence structural evolution and enhance properties for boron lead silicate glasses. This provides a theoretical basis for further advances to improve material properties and expand optical and electronic applications.

Numerical Simulation and Experimental Analysis for Microwave Sintering Process of Lithium Hydride (LiH)

Dense lithium hydride (LiH) is widely used in neutron shielding applications for thermonuclear reactors and space systems due to its unique properties. However, traditional sintering methods often lead to cracking in LiH products. This study investigates the densification sintering of LiH using microwave technology. A multiphysics model was established based on the measured dielectric properties of LiH at different temperatures, allowing for a detailed analysis of the electromagnetic and thermal field distributions during the microwave heating of cylindrical LiH samples. The results indicate that the electric field distribution within the LiH is relatively uniform, with resistive losses concentrated primarily in the LiH region of the microwave cavity. LiH rapidly absorbs microwave energy, reaching the sintering temperature of 520 °C in just 415 s. Additionally, the temperature difference between the low- and high-temperature regions during the sintering process remains below 5 °C, demonstrating excellent uniform heating characteristics. The microwave sintering process enhances interface migration within the LiH samples, resulting in dense metallurgical bonding between grains. In summary, this research provides valuable insights and theoretical support for the rapid densification of LiH materials, highlighting the potential of microwave technology in improving material properties.

Photooxidation of Polyolefins to Produce Materials with In-chain Ketones and Improved Materials Properties.

Herein, we report a selective photooxidation of commodity postconsumer polyolefins to produce polymers with in-chain ketones. The reaction does not involve the use of catalyst, metals, or expensive oxidants, and selectively introduces ketone functional groups. Under mild and operationally simple conditions, yields up to 1.23 mol% of in-chain ketones were achieved. Installation of in-chain ketones resulted in materials with improved adhesion of the materials and miscibility of mixed plastics relative to the unfunctionalized plastics. The introduction of ketone groups into the polymer backbone allows these materials to react with diamines, forming dynamic covalent polyolefin networks. This strategy allows for the upcycling of mixed plastic waste into reprocessable materials with enhanced performance properties compared to polyolefin blends. Mechanistic studies support the involvement of photoexcited nitroaromatics in consecutive hydrogen and oxygen atom transfer reactions.

Improved material properties of wire arc additively manufactured Al-Zn-mg-cu alloy through severe deformation interlayer friction stir processing and post-deposition heat treatment

In this study, Al-Zn-Mg-Cu alloys were prepared by wire arc additive manufacturing (WAAM) combined with interlayer friction stir processing (IFSP). To enhance the FSP region, an improved stirring pin was designed to broaden the stir zone effectively. Moreover, the effects of typical T6 and T73 heat treatments on the microstructure and mechanical properties of as-deposited (AS) specimen were meticulously investigated. The results indicated that heat treatments had minimal impact on grain size, dislocation density, and texture strength, but significantly altered the type, size, and distribution of precipitates. The differences in strength were primarily attributed to precipitation strengthening rather than grain boundary or dislocation strengthening. Following T6 heat treatment, the precipitates were predominantly η’, which were smaller in size and exhibited a significantly increased number density compared to AS specimen. Therefore, the average yield strength (YS) and ultimate tensile strength (UTS) increased by 39.51 % (500.21 MPa) and 15.84 % (584.26 MPa), respectively. In contrast, T73 treatment caused a substantial number of fine η’ to transform into coarser η, leading to a significant decrease in precipitate number density. Consequently, compared to T6 specimen, the average YS and UTS decreased by 47.19 % and 13.13 %, respectively.

Harvesting low-grade wind energy from highways using a triboelectric nanogenerator

In an era of growing global energy demands, the exploration of niche energy harvesting methods is becoming increasingly important, and harnessing wind energy from highways presents a promising approach to sustainable infrastructure development given the high traffic of many roads. In this work, we report a cylindrical spinning TENG (CS-TENG) for low-grade wind energy harvesting from highways. Through empirical analysis and theoretical modeling, we investigate the feasibility of integrating CS-TENG devices along highway barriers to capture the wind energy generated by passing vehicles, which could contribute to powering streetlights and other road infrastructure in a more eco-friendly way. Our findings highlight broader societal and environmental benefits including enhancing road safety, traffic management, and energy sustainability. A single 100 mm tall CS-TENG device was tested with approximately 4 m/s wind speed and produced an open circuit voltage of 8 V and a short circuit current of 800 µA. This electrical output can be increased with an elevation in the device number, the device size, and improved material properties. This study contributes to the growing discourse on sustainable infrastructure solutions, inspiring further research and innovation in renewable energy harvesting for carbon neutrality.

Facile construction of CeO2@MoS2 nanohybrid for enhancing tribological performance of electroplated Co-based composite coatings

Developing and manufacturing novel coatings with excellent tribological performance using environmentally friendly and simple methods hold significant potential and challenge for reducing energy consumption and carbon emissions. Here, we use a gentle method to synthesize the MoS2-load CeO2 nanohybrid (CeO2@MoS2) as an additive to construct a Co-CeO2@MoS2 composite coating with friction reduction and wear resistance through a low-cost electrodeposition technique. The friction measurement results show that CeO2@MoS2 nanohybrid effectively reduces the friction coefficient and increases the wear resistance compared to single CeO2 or MoS2. The synergistic effect of hard CeO2 and soft MoS2 gives the Co-CeO2@MoS2 coating with an extremely low coefficient of friction of about 0.05 and a wear rate of about 3.53×10−6 mm3(N·mm)−1. In addition, the Co-CeO2@MoS2 coating can maintain an extremely low coefficient of friction with long-term stability in tribological tests. This work provides a novel strategy for constructing coatings with remarkable tribological performances and promotes the application of CeO2@MoS2 nanohybrid as an additive to improve material properties.

Influences of symmetric tilt grain boundary on the stretching deformation behaviors of Cu bicrystals

The microstructure of grain boundary (GB) becomes an important factor affecting the strength of nanomaterials during plastic deformation. In this work, Cu bicrystals with different coincidence site lattice (CSL) interfaces are constructed, and the influences of the symmetric tilt interface on the mechanical properties and plastic deformation behaviors during uniaxial tension are studied by molecular dynamics simulation. The results indicate that the peak stress of tensile stress-strain curves for most bicrystals is lower than its monocrystalline samples, except CSL3, CSL11 and CSL57 bicrystals with a continuous and single structural unit. The CSL3 bicrystal has the highest strength, while CSL33 bicrystal has the lowest strength among all the tested samples. The CSL11 and CSL57 bicrystals with a lower GB energy have a higher stability of interface, which delays the yielding. Moreover, the generation of twin and stair-rod dislocation at the interfaces strengthens the CSL11 and CSL57 bicrystals. The CSL3 almost has the same parameters as its monocrystalline sample S3, massive research has confirmed that the sample with a higher density twin (CSL3 interface) exhibits higher combined properties of strength and plasticity. This work may provide a guideline for GB engineering to improve material properties by controlling the GB structure.

Improvement of magnetic properties and hardness by alloying Mo to a FeCrCo alloy

In most of the technologies used for improving material properties, the enhancement of some properties usually leads to the degradation of others. In this study, we demonstrated that we were able to simultaneously improve hardness, coercivity, and remanence by alloying an FeCrCo alloy with Mo by engineering its α → α1 + α2 spinodal decomposition. We prepared six Mo-alloyed samples and subjected them to the appropriate aging protocols. As aging progressed, hardness increased from 272 to 447 HV and coercivity increased from 47 to 592 Oe in the alloyed samples. Remanence gradually increased from 52 to 98 Am2/kg, and then decreased to 82 Am2/kg in the final stage of the aging process. By adding Mo to six individual FeCrCo samples aged to different stages, we increased the hardness of these samples by 3 %, 8 %, 7 %, 8 %, 5 %, and 10 %, respectively. At the same time, we increased their coercivity by 74 %, 13 %, 19 %, 4 %, 14 %, and 9 % respectively and their remanence by 82 %, 63 %, 4 %, 4 %, 9 %, and 13 %, respectively. We used data drawn from scanning transmission electron microscopy, first-principles calculations, and magnetic force microscopy in order to elucidate the reasons behind the observed enhancements of magnetic properties in the FeCrCoMo alloy.

Mechanical properties and stability of hot rolled Zn-0.8Mg alloy

Insufficient mechanical strength and mechanical instability are important factors limiting the application of zinc-based alloys as biodegradable materials. Currently, alloying and plastic deformation are effective methods to improve material properties. Therefore, this paper investigates the effect of hot rolling process on the mechanical properties and stability of Zn-0.8Mg alloys. The results show that after hot rolling, the internal grain of Zn-0.8Mg alloy is refined, the second phase is precipitated, the weaving strength is enhanced, and the overall mechanical properties are significantly improved. The contribution of deformation strengthening can reach about 90 %. The tensile strength, yield strength, and elongation of the alloy were 312.3 MPa, 249.5 MPa, and 15.6 % (141.72 %, 155.96 %, and 189.96 %, respectively) at a rolling volume of 70 %, which meets the clinical criteria for degradable material implants. However, this treatment reduced the stability of the mechanical properties of the Zn-0.8Mg alloy. During natural ageing, a small amount of Mg2Zn11 phase precipitated inside the alloy, reducing the elongation. Compared with cast alloys, hot rolled alloys have higher grain boundary density, which accelerates the precipitation of secondary phases, leading to more pronounced changes in the mechanical properties of the alloys after hot rolling.

Explosively welded SLM-AlSi10Mg/SLM-SUS316L: Unveiling superiority of interlayer welding for enhanced mechanical properties

Following the advent of three-dimensional (3D) printing technology, multi-material 3D printing has garnered significant attention due to its potential to enhance the flexibility and development of high-performance 3D printing materials. This study investigated the application of explosive welding to create multi-material 3D printed structures. Specifically, we explored the use of direct and interlayer explosive welding to fabricate SLM-AlSi10Mg/SLM-SUS316L explosive composites with the aim of further improving material properties. Our primary objective was to explore the unique interfaces and mechanical characteristics of 3D printed materials subjected to explosive impact loading. This study provides a new idea of 3D printing multi-materials, which is of great significance for the development of both explosive welding and 3D printing. The results demonstrated the feasibility of using explosive welding to create multi-material composites from 3D printed metals, including both direct and interlayer welding of SLM-AlSi10Mg/SLM-SUS316L. Interlayer welding exhibited superior mechanical performance compared to direct welding, with a 70%–250% increase in strength observed in the macro tensile shear test. Additionally, samples fabricated with a 40 mm explosive thickness displayed more stable and exceptional performance in the micro tensile test. Corrosion testing and X-ray computed tomography (XCT) analysis were employed to investigate the distribution of pores within the 3D printed materials.

Effects of multilayer MoS2 coating on the mechanical properties of metals: A competition between external force and interfacial adhesion

Molybdenum disulfide (MoS2) is a two-dimensional material that exhibits unique interfacial interactions with metals, making it potential coating material for improving material properties of metals. In this work, the effects of multilayer MoS2 coating on the mechanical properties and deformation behaviours of copper (Cu) and gold (Au) substrates are investigated by nanoindentation experiments and molecular dynamics (MD) simulations. Specifically, our experimental results indicate that the MoS2 coating greatly increases the Young's modulus and hardness of Au substrate throughout the indentation process. In the MoS2/Cu system, however, the MoS2 coating exhibits inverse effects at diffident indentation depths, which, specifically, has the weakening and enhancing effects at the early and late stages of the indentation process, respectively. MD simulations indicate that the different effects of the MoS2 coating on the mechanical properties of Au and Cu substrates are attributed to the different interfacial adhesion properties between the MoS2/Cu and MoS2/Au systems, as the binding energy of the MoS2/Au system is much larger than that of its MoS2/Cu counterpart. Moreover, it is also revealed in MD simulations that the load-bearing area of metal substrates can be significantly enlarged by the MoS2 coating, which leads to the dense dislocations distributed in metal substrates and thus the strain-hardening in MoS2/metal composites.

Synthesis of calcium sulfate whiskers via acidification exploiting FGD gypsum for improved binder properties

This research focuses on the synthesis of calcium sulfate whiskers using FGD (Flue Gas Desulfurization) gypsum as raw material through the acidification method and their utilization in gypsum binders. The acidification method using H2SO4 (1.5 mol/L) is distinguished by its sustainability and resource efficiency. The addition of Calcium Sulfate Whisker as an activator enhances the binder's properties by increasing its strength, durability, resistance to environmental factors, and overall structural integrity. The effects of different reaction parameters on the properties and microstructure of CSW have been studied. This research has the potential to bring about significant improvements in various applications, from construction materials to industrial products. Calcium Sulfate Whiskers act as pore fillers within the binder matrix which reduces the porosity and helps to decrease water absorption up to 12%. CSW is characterized by its needle-like structure, which provides an intricate network within the binder matrix. SEM images showed the strong interfacial bonding between the whiskers and the binder matrix, enhanced by the rough surface of the whiskers, which improves mechanical interlocking and adhesion. CSW demonstrates its potential as a highly active component in the binder. The whiskers facilitate efficient nucleation sites, accelerating the hydration reactions within the binder and enhancing the overall performance of the binder. CSW incorporation in the binder increases the compressive strength by up to 21.6% and flexural strength by 37%. The exceptional mechanical strength and efficient nucleation sites provided by CSW contribute to an increase in the workability of the binder and make it suitable for interior as well as exterior applications. These interconnected facets collectively position the project as a valuable and highly pertinent contribution, where sustainable innovation and improved material properties are of paramount importance. It potentially reduces the need for traditional additives with higher environmental impacts, making the binder formulation more eco-friendly.

Rational Design of Deep Learning Networks Based on a Fusion Strategy for Improved Material Property Predictions.

The success of machine learning in predicting material properties is largely dependent on the design of the model. However, the current designs of deep learning models in materials science have the following prominent problems. First, the model design lacks a rational guidance strategy and heavily relies on a large amount of trial and error. Second, numerous deep learning models are utilized across various fields, each with its own advantages and disadvantages. Therefore, it is important to incorporate a fusion strategy to fully leverage them and further expand the design strategies of the models. To address these problems, we analyze that the main reason is the lack of a new feedback method rich in physical insights. In this study, we developed a feedback method called the Chemical Environment Clustering Vector (CECV) of compounds at different thresholds, which is rich in physical insights. Based on CECV, we rationally designed the Long Short-Term Memory and Gated Recurrent Unit fused with Deep Convolutional Neural Network (L-G-DCNN) to explore the field of structure-agnostic material property predictions. L-G-DCNN accurately captures the interactions between elements in compounds, enabling more accurate and efficient predictions of the material properties. Our results demonstrate that the performance of the L-G-DCNN surpasses the current state-of-the-art structure-agnostic models across 28 benchmark data sets, exhibiting superior sample efficiency and faster convergence speed. By employing different visualization methods, we demonstrate that the fusion strategy based on CECV significantly enhances the comprehension of the L-G-DCNN model design and provides a fresh perspective for researchers in the field of materials informatics.

Enhancing ASTM B424 UNS N08825 Long Seam Weld Liner Material with Annealing Quenching Techniques in the Cladding Process on the Surface of Steel Pipes

The use of cladding methods in manufacturing corrosion-resistant pipes is crucial for industries such as oil and gas, chemical plants, and pressure vessel manufacturing. This study focuses on ASTM B424 UNS N08825, a corrosion-resistant alloy (CRA) to be used as the surface layer for steel pipes. The cladding method involves forming CRA sheets into longitudinal pipes, followed by welding the joints, annealing, and rapid cooling before high process expansion to surface layer the steel pipes. At a temperature of 930-990°C, the annealing process aims to reduce stress and improve material properties, followed by rapid cooling to stabilize the microstructure. Various tests were conducted on the CRA liner pipes with or without annealing and quenching, including tensile testing, hardness testing, chemical composition analysis, and microstructure examination. The results showed that the material's ultimate tensile strength and hardness significantly increased after the treatment, with better uniformity in the microstructure. This study concludes that annealing and rapid cooling enhance the mechanical properties and stability of ASTM B424 UNS N08825, allowing the cladding process on steel pipe surfaces to be performed flawlessly and making it suitable for high-performance applications in corrosive environments.

Toward Ultra-High Sensitivity Optical Thermometers and Bright Yellow LEDs Based on Phonon-Assisted Energy Transfer in Rare Earth-Doped La2ZnTiO6 Double Perovskite.

Double perovskites, a class of ceramic oxides with unique crystal structures and diverse physical properties, show promise for various technological applications including solar cells, photodetectors, and light-emitting diodes (LEDs). Despite limited research on rare earth-doped double perovskites, leveraging their ultrahigh luminous efficiency to achieve bright yellow LED emission and addressing energy transfer challenges between Yb3+ and Nd3+ ions in double perovskite La2ZnTiO6 with moderate phonon energy are explored in this work. Through phonon-assisted energy transfer, an ultrasensitive optical thermometer covering a wide temperature range is developed by utilizing the different temperature responses of Er3+ emission in the visible light region and Nd3+ emission in the near-infrared region based on the luminescence intensity ratio (LIR). All the results demonstrate that the rare earth (Yb-Er, Yb-Nd, and Yb-Nd-Er)-doped La2ZnTiO6 phosphors can be effectively utilized for ultrabright LED illumination and ultrahigh sensitivity self-calibrated temperature sensing. This research underscores the significance of phonon-assisted energy transfer in improving material properties and provides valuable insights for the advancement of multifunctional materials.

Analysis of crack propagation of PLA fabricated by the additive manufacturing technique

Understanding crack propagation is crucial for evaluating the structural integrity and reliability of additive manufacturing components, as cracks can compromise mechanical properties and potentially lead to catastrophic failures. The study of crack propagation in additive manufacturing components is used to develop strategies for mitigating crack initiation and growth, improving material properties, and optimising the design and manufacturing processes. Crack propagation in additive manufacturing components can be influenced by various factors, including material properties, design considerations, manufacturing defects, and loading conditions. Due to the identified issue, the study was carried out to investigate the crack propagation of the Fused Deposition Modeling (FDM) component using compact tension fracture testing. The experimental work started with fabricating the samples using PLA material, followed by a fracture test based on the compact tension specimen test to get a response of the structure and its crack propagation under tensile. Material properties were also collected using the dog bone tensile test. The material properties of the testing were then imported to Finite Element Analysis for further investigation of fracture mechanics. It was found that the maximum force of the sample was 141.7 ± 28 N at 1.70 ± 0.26 mm displacement, and cracks initiated around the tip and propagated upward or downward based on the initial crack location. The deformation patterns of PLA material have shown it to be brittle plastic deformation and low energy absorption before fracture.

Impact of biodegradable plastics on U.S. environmental conservation: A comprehensive review, exploring the effectiveness, challenges, and broader implications of bioplastics in waste management and eco-preservation

This study provides a comprehensive review of the emergence of biodegradable plastics as a paradigm shift in materials science, aiming to assess their development, implementation, and impact on environmental conservation and sustainable development. Employing a systematic literature review and content analysis methodology, the research scrutinizes academic databases and industry reports to explore the technological innovations, environmental benefits, and challenges associated with biodegradable plastics. The inclusion and exclusion criteria ensure a focused examination of peer-reviewed articles, highlighting advancements in biopolymer formulations, regulatory frameworks, and stakeholder perspectives. Key findings reveal that biodegradable plastics offer significant potential for reducing plastic pollution and mitigating climate change impacts due to their renewable origins and compostability. However, challenges such as technical limitations, higher production costs, and the need for specialized waste management infrastructure hinder their widespread adoption. The study underscores the importance of developing standardized biodegradation protocols, investing in research and development, enhancing waste management systems, and educating stakeholders to overcome these barriers. Conclusively, biodegradable plastics represent a promising avenue towards sustainable materials management, provided that concerted efforts are made to address the existing challenges. Strategic recommendations include fostering public-private partnerships, improving material properties, and implementing supportive policies to enhance the role of bioplastics in environmental preservation. Future research should focus on innovating bioplastic technologies and exploring effective strategies for their integration into the circular economy. Keywords: Biodegradable Plastics, Environmental Conservation, Sustainable Development, Waste Management.

N-doped carbon achieved by pyrolyzing urea and active carbon for the capacitive deionization coupled PMS oxidation system

Tetracyclines are among the most widely used antibiotics, and the saline organic wastewater generated during their production has caused serious environmental problems. Thus, it is imperative to develop effective methods for treating this antibiotic wastewater. In this study, we examined the structural characteristics and electrochemical performance of nitrogen-doped carbon materials and assessed the effects of nitrogen doping on the performance of a peroxymonosulfate (PMS)-coupled membrane capacitive deionization (MCDI) system for removing tetracycline (TC) and salt. Having optimized the carbonization temperature and system operating parameters, we observed that in response to an increase in carbonization temperature, there was an increase in the abundance of surface functional groups in the material, which promoted the ion migration capacity of the electrode and PMS activation sites. In addition, we observed that nitrogen doping can alter the electrical properties of carbon materials, provide a larger number of adsorption sites, and enhance the interactions between carbon structures and salt ions, thereby improving material properties. Under optimal operating conditions, the salt adsorption and tetracycline removal rates reached 30.2 % and 61.8 %, respectively. Our findings in this study provide a feasible method for the treatment of saline tetracycline wastewater.

A Comprehensive Study of Friction Stir Processing Technique

Friction Stir Processing technique is a surface modification method that transforms heterogeneous microstructures into homogeneous ones, enhancing the mechanical properties of metal sheets. This single-step process, introduced by The Welding Institute (TWI) in 1991, offers advantages such as superior strength and formability, especially in aluminum alloys. FSP's simplicity, cost-effectiveness, and environmental friendliness make it preferable over traditional methods. Despite challenges in aerospace and transportation applications, FSP shows promise for forming lightweight alloys at room temperature. However, producing ultrafine grain sheet metals remains a challenge. Overall, FSP presents a viable solution for improving material properties and processing efficiency in various industrial applications. This study includes the literature review of research publications from different researchers to develop the understanding regarding friction stir processing technique.