Journal of Material Science and Technology Research

Enhancing Mechanical Properties of a Lightweight TiAlCrNbVZr Medium-Entropy Alloy: Fine-Tuning Alloy Composition and Thermomechanical Treatment

Po-Sung Chen — 2024-03-04

Abstract: The quest to reduce fuel consumption and environmental pollution in the transportation sector has heightened the demand for developing lightweight alloys with enhanced mechanical properties. Accordingly, this study focused on optimizing the mechanical properties of a lightweight Ti₆₅(AlCrNbV)₂₈Zr₇ medium entropy alloy (MEA) by strategically adjusting its Al, Cr, Nb, and V elemental contents. Hardness testing indicated a strengthening ability hierarchy of Cr > Al > V > Nb. Furthermore, tensile tests revealed that although a high Cr content significantly enhances strength, it also reduces the ductility of an MEA. Drawing on mechanical insights gained from a previously studied Ti₆₀Al₁₀Cr₁₀Nb₁₀V₁₀ MEA and the present findings, a novel Ti₆₀Al₁₀Cr₄Nb₁₀V₉Zr₇ (Ti60Zr7) MEA was developed. This new alloy retains a single body-centered cubic structure and demonstrated exceptional mechanical performance in tensile testing, with a yield strength of 1066 MPa and 22% ductility. The Ti60Zr7 MEA underwent a series of thermomechanical treatments, including 50% hot rolling, 80% cold rolling, and rapid annealing up to 800 °C at a rate of 25 °C/s. After thermal processing, the Ti60Zr7 MEA not only preserved its single body-centered cubic structure but also achieved a remarkable combination of yield strength (>1200 MPa) and ductility (measured as >15% elongation). These advancements underscore the alloy’s considerable potential for application in sports equipment and transportation vehicles.

Formation Mechanism of Eutectic Microstructure for Ca(Zr,Hf)O3/(Zr,Hf)O2 by Rapid Solidification Process at High Temperature

Shunkichi Ueno — 2024-08-07

Abstract: Ca(Zr_1-x,Hf_x)O₃/(Zr_1-xHf_x)O₂(x=0, 1/3, 0.5) eutectic film was prepared by rapid solidification process using high power laser irradiation method. The coating process was performed in an electric furnace at 1300°C. Solidified film with fine lamellar structure were obtained. When the Zr site was substituted with Hf, the lamellar spacing increased with the amount of the substitution. Separate from the solidification film prepared by laser irradiation, rapidly solidifying sample with x=0.1 composition was prepared using optical floating zone apparatus. The melt of the sample was free-fallen onto a copper dish. No film-like rapidly solidified sample was obtained. Hf ion was homogeneously solid-soluble in both phases of CaZrO₃ and phase ZrO₂.

Evaluation of Mechanical Properties and Hydrophilicity of Alkaline and Plasma Treated Abaca Fiber Epoxy Composite with Mineral Waste as Fillers

Praneeth D. Bangaru — 2024-08-16

Abstract: Natural fiber composites (NFC) are increasingly recognized for their sustainability and versatility. Abaca fiber is one of the prominent natural fibers that are sourced from the leaf sheaths of the abaca plant. This study provides an overview of the comparison of the mechanical properties and water uptake behavior of surface-modified N₂ plasma and alkali treated abaca fiber-reinforced epoxy composites with granite powder used as fillers. It mentions the use of varying filler content (0 wt.%, 10 wt.%, 20 wt.%, and 30 wt.%) in both the pre-treated composites and compares their properties. Plasma-treated granite filler samples showed superior tensile strength and flexural properties, despite a negative effect on impact properties. A lower water absorption is observed in plasma-treated composites with fillers compared to those without fillers. Overall, the potential of surface modification techniques with granite-based mineral fillers is apparent in improving the performance of N₂ plasma treated NFCs, thus expanding their applications across different industries aiming for the good mechanical hygroscopic properties.

Vibrocasting of Silicon Carbide Based Concrete Materials

O.D. Pashkov — 2024-08-21

In order to reduce the water demand of silicon carbide vibratory casting masses with high-alumina cement additives, the impact of various deflocculant of different natures to silicon carbide vibratory casting masses was investigated. The deflocculants used included polycarboxylate ether-based, sodium polyacrylate, high-molecular-weight poly-N-vinylpyrrolidone, and sodium salts of polymethylene-β-naphthalenesulfoxylic acid. Multifractional compositions of silicon carbide (2-3 mm, 1-2 mm, 0,5-1 mm, 0,2-0,5 mm, 0,063-0,12 mm fractions) with high-alumina cement and silicon additives, as well as with deflocculants, were studied. The firing of the materials was conducted in an oxygen atmosphere at temperatures between 1000 and 1400˚С. The adverse effect was demonstrated for deflocculant based on sodium polyacrylate and high-molecular-weight poly-N-vinylpyrrolidone, as the usage of these additives increases the water demand of the mix. A smaller amount of water used for the mass production allows the processing of more dense materials with reduced open and closed porosity. Using deflocculants, the moisture content of the material is reduced to 6.5%.

Material Selection and Design for Assembly Applied in the Development of an Energy Generating Device

Eduardo Luis Schneider — 2024-09-20

This study used the Design for Assembly (DFA) and material selection methods as tools to aid the development of a conceptual design of a functional device to transform alternate movement into rotational movement on the axis of a microgenerator. Also, material selection software was used to define the most suitable thermoplastic materials for some components of the projected device, focusing both on performance and low cost. There was a considerable reduction in the number of parts in the set from the basic device (prototype), which had 47 parts, to the conceptual design I, with 34 parts, and the conceptual design II, with 14 parts. The total mass of the set was also considerably reduced, from 160 grams for the basic device to 57.01 grams in the conceptual design I and, finally, 18.30 grams in the conceptual design II. Of thermoplastic materials analysed, considering a selection focused only on performance the most promising candidate, with an ideal set of properties is PEEK. But for a selection that considers the price, that is one of the key variables in the materials selection for most products, PEEK shows is prohibitively price.

Organic and Inorganic Modified Montmorillonite as a Scavenger of Formaldehyde in Modified Urea-Formaldehyde Composites

Marija Krstić — 2024-09-24

This research used montmorillonite (K10) modified with Hexadecyltrimethylammonium bromide (HDTMABr), and sulfuric acid (H₂SO₄). The samples are marked with MMT, OMMT for organic-modified montmorillonite, and AMMT for inorganic-modified montmorillonite. UF resin with a molar ratio FA/U = 0.8 was synthesized in situ with modified and unmodified MMT. X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), non-isothermal thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to characterize the MMT samples. The degree of activation was determined based on the measurement of specific surface area, which was determined by the Sears method. The sulfite method was used to determine free and released formaldehyde from synthesized urea-formaldehyde/montmorillonite (UF/MMT) composites. SEM analysis showed changes in the OMMT morphology and the formation of a hollow network, affecting the clay's absorption capacity. Measurement of the specific surface area shows that higher values were obtained for AMMT (183 m²/g) compared to OMMT (13.5 m²/g). Despite that, the free and released formaldehyde amount was 0.06% and 4.6% for UF/AMMT and 0.1% and 1.0% for UF/OMMT. The larger interlayer spacing and hydrophobic nature of OMMT make it an effective barrier within the UF resin matrix.

Circular Economy: A Network Analysis of the Solid Waste Collection in the City of Rome (Italy)

Giorgio Tosato — 2024-09-25

Solid waste management represents a complex issue involving political, socioeconomic, institutional, urbanistic and environmental aspects. Separate collection of waste in the Municipality of Rome is a matter of particular interest due to the size of the city (with an urban area of 1,287 km²) and the considerable amount of waste produced (approximately 1,690,000 tons/year). In this context, this paper proposes an in-depth analysis with the aim of optimizing the delivery of waste to collection centres. The optimization focuses on several key elements, including the strategic distribution of collection centres within the city to make them easily accessible, particularly in densely populated areas or where waste production is higher.

Based on the data provided by the Municipality of Rome, the waste materials that should be advantageously recycled as part of the Life Cycle Assessment (LCA) have also been identified. This comprehensive approach can improve the city’s waste management system, promoting the efficient use of resources and reducing environmental impact for greater urban sustainability.

Detecting Magneto-Optical Interactions in Nanostructures

Luana Hildever — 2024-09-30

Effects due to magneto-optical interactions are responsible for most of the phenomena discovered in optoelectronics and spintronics. Magneto-optical interactions can generate elementary excitations of the order of light-magnetic matter, which can flow under certain conditions. Here, we observe the intensities of magneto-optical interactions in hexagonal arrays of magnetic nanowires using experimental measurements and simulations. Nanowires of three materials (cobalt-Co, iron-Fe, and nickel-Ni) were electrodeposited on alumina membranes by the AC electrodeposition method. Our results reveal that the magneto-optical behavior can produce, under certain conditions, a kind of avalanche of magneto-optical interactions, which is dynamic. Such an observation shows the possibility of generating a magneto-optical current (spin-opto current).

Bacterial Cellulose: A Multifunctional Platform for Biomedical Applications

Ricardo Barbosa de Sousa — 2024-10-08

Bacterial cellulose (BC), a biopolymer synthesized by various bacterial species, has emerged as a promising material for biomedical applications due to its unique properties, including high purity, biocompatibility, mechanical strength, and structural similarity to the extracellular matrix. This review explores the advancements in BC research over the last decade, focusing on its applications in tissue engineering, wound healing, and drug delivery systems. While BC offers numerous benefits, challenges such as large-scale production, structural modification, however regulatory approval hinder its broader clinical use. Recent studies have introduced innovative solutions, such as using agro-industrial waste to lower production costs and combining BC with other materials to enhance its bioactivity. As research progresses, BC has the potential to revolutionize the field of biomedicine, offering sustainable, versatile, and effective solutions for a wide range of medical applications.