Materials Science Forum Vol. 1196

Abstract: Utilizing these wastes not only helps reduce the volume of industrial waste but also adds value to the final product. The fabrication of test materials in this study employed the compression moulding method with variations in fly ash volume fractions of 5%, 10%, and 15%, as well as variations in compaction loads of 1 ton, 2 tons, and 3 tons. This study aims to investigate the effect of hydraulic compression load and fly ash volume fraction on the impact strength of sugarcane fiber-reinforced composite materials using the compression molding method. The compression moulding specimens were then subjected to impact testing to determine the impact strength and macro photography to analyze the fracture pattern of the material. The results showed that the higher the fly ash volume fraction at the same compression load and the higher the hydraulic load variation at the same volume fraction, the greater the increase in the material's impact strength. The average impact strength values for fly ash volume fractions of 5%, 10%, and 15% with a 1-ton load were 0.068 Joules/mm², 0.073 Joules/mm², and 0.085 Joules/mm², respectively. The average impact strength for specimens with a fly ash volume fraction of 5%, 10%, and 15% with a 2-tons load were 0.071 Joules/mm², 0.076 Joules/mm², and 0.087 Joules/mm². In the case of composite specimens with a fly ash volume fraction of 5%, 10%, and 15% with a 3-tons load, the impact strength values were 0.072 Joules/mm², 0.082 Joules/mm², and 0.096 Joules/mm², respectively.

Abstract: Natural fiber-reinforced composites have emerged as sustainable alternatives to synthetic composites owing to their biodegradability, high availability, and low cost. Among them, banana midrib fiber offers great potential as reinforcement due to its high cellulose content and abundance as agricultural waste. This study investigates the optimization of tensile strength in unidirectional banana midrib fiber-reinforced composites by examining the influence of fiber volume fraction. Banana midrib fibers were treated with 3% and 4% Natrium Hydroxide (NaOH) solutions to enhance interfacial bonding and then combined with polyester matrix to fabricate composite specimens. Tensile strength was evaluated experimentally according to ASTM D638 standards, while theoretical predictions based on the Rule of Mixtures and statistical modeling using Response Surface Methodology (RSM) were employed for validation and optimization. The results show that tensile strength increased with fiber content up to a critical volume fraction, which fiber agglomeration led to reduced performance. The maximum tensile strength of 44.4 MPa was achieved at a fiber volume fraction of approximately 42% with 4% NaOH solution. RSM demonstrated strong predictive accuracy, with results closely matching experimental data. These findings confirm that both fiber treatment and optimized fiber loading play a decisive role in achieving superior mechanical performance, supporting the use of banana midrib fibers in sustainable engineering applications.

Abstract: The growing environmental awareness has driven material industries to seek sustainable alternatives to synthetic fibers. Abaca fiber (Musa textilis), a superior natural fiber with excellent tensile strength and seawater resistance, presents significant potential for sandwich composite applications. This review paper aims to synthesize recent advancements in utilizing abaca fiber as a core and face sheet material in sandwich composite structures. A systematic literature review of indexed journal articles from the last decade was conducted. The review identifies that chemical treatments and hybrid configurations with other fibers significantly enhance the mechanical properties and moisture resistance of abaca-based sandwich composites. Furthermore, this paper analyzes the prospects and challenges of integrating this material into the shipbuilding industry, particularly for interior panels, partitions, and lightweight non-structural components. The analysis shows that while promising, widespread adoption in marine applications requires further research on long-term durability, material standardization, and life cycle analysis to comprehensively demonstrate its economic and environmental advantages.

Abstract: Natural fibers are increasingly recognized as sustainable alternatives to synthetic reinforcements in polymer composites due to their biodegradability, high availability, and low production cost. However, their mechanical performance is often inconsistent, making it crucial to evaluate predictive models that estimate tensile strength. This study investigates the reliability of theoretical predictions based on the Rule of Mixtures (ROM) in unidirectional composites reinforced with various natural fibers, including bamboo, coconut, pineapple, banana midrib, and sugar palm fibers. Fibers were subjected to alkali treatment prior to composite fabrication with a polyester matrix, and tensile tests were performed following ASTM D-638 standards. Theoretical predictions of optimum tensile strength were determined at minimum, Vmin and critical, Vcrit fiber volume fractions. The tensile strength based on theoretical prediction are then compared to the experimental results. The results show that bamboo fiber achieve optimum tensile strength of 51.92 MPa with relatively low fiber volume fractions. In contrast, the banana fiber achieves the lowest tensile strength of 39.10 MPa. Overall, the theoretical approach exhibited good agreement with experimental trends, particularly in predicting optimum fiber fractions, validating its utility as a preliminary design tool for natural fiber-reinforced composites.

Abstract: Conventional plastic waste poses a serious environmental problem due to its resistance to degradation. This study developed an eco-friendly bioplastic made from banana peel waste, reinforced with graphene oxide (GO) as a filler. The bioplastics were synthesized using the melt-blending method with GO concentrations of 0%, 0.5%, 1%, 1.5%, and 2%. Tensile strength tests showed that the bioplastic with 2% GO exhibited the highest mechanical performance, with a tensile strength of 26.15 N/cm² and a Young’s modulus of 130.73 MPa, compared to the non-graphene sample which only reached 22.64 N/cm² and 113.23 MPa. Biodegradability tests using the soil burial method over 6 days revealed that the non-graphene sample had the fastest degradation rate, with a weight loss of up to 45%, outperforming the graphene-reinforced variants. The results indicate that while GO enhances mechanical properties, it reduces the biodegradation rate. Therefore, banana peel-based bioplastic offers a promising, sustainable alternative to conventional plastics adaptable either for high-strength applications or for products designed to degrade more rapidly in natural environments.

Abstract: Epoxy is the most commonly used thermosetting polymer in various parts of aircraft, spacecraft, sports cars and construction owing to their long life, light weight and high strength. As epoxy is a thermosetting polymer, its recycling is a big challenge. After its usage, most of it goes to landfilling, which has a greater impact on soil pollution and degradation of soil fertility. In order to overcome this drawback, recycling of thermoset epoxy is necessary to save the environment as well as to reduce the supply of new material. This article describes the effect of recycled epoxy microparticle reinforcement on the flexural, hardness and impact behaviour of acrylonitrile butadiene styrene. In the process, specimens of composite with virgin ABS as a matrix material and recycled epoxy microparticles as a reinforcement are fabricated using a micro compounder with an injection moulding machine. The specimens are tested to assess mechanical properties such as flexural strength, impact strength and Shore D hardness. The ABS Epoxy (ABSE) composite mechanical properties have been slightly influenced by the cross-linked epoxy microfillers. The flexural strength increases with an increase in the proportion of cross-linked epoxy microparticles of up to 10%, then later reduces slightly compared to neat ABS. Izod Impact resistance of the composite decreases with an increase in cross-linked epoxy microparticle percentage. Shore D hardness of the composite increases with increases in epoxy proportion, and the maximum value of Shore D hardness is obtained for 20% cross-linked epoxy proportion. SEM images confirm uniform dispersal of filler material and shows fracture behaviour of the composite in correlation with test results obtained. ABSE composite with enhanced flexural property and hardness can be successfully used in structural and other engineering applications with more durability and sustainability as well.

Abstract: Diluted magnetic semiconductors (DMS) have the unique ability to manipulate both the spin and charge of electrons simultaneously. This property makes them potentially useful in spintronics and quantum computing, two fields that have attracted prolonged attention. The achievement of ferromagnetism at room temperature and the revelation of the origin of ferromagnetism of DMS pave the way for fabricating this material on an industrial scale. To date, reports of DMS achieving ferromagnetism at room temperature have mostly been carried out using sputtering, pulsed laser deposition, and sol-gel method. However, the lack of research reports on electrodeposition techniques for DMS films remains a notable gap in current knowledge. This review focuses on recent progress in fabricating DMS using the electrodeposition method, which is a non-vacuum, simple, and low-cost technique. This review aims to reveal the challenges and opportunities involved in developing this fabrication method. The important properties of DMS films fabricated by electrodeposition, such as their crystal structure, optical properties, morphology, and magnetic properties will be reviewed.

Abstract: In this work, iron oxide materials α-Fe₂O₃ and Fe₃O₄ were investigated as alternative electron and hole transport layers (ETL and HTL) in planar perovskite solar cells (PSCs). Devices were fabricated with the configuration ITO/α-Fe₂O₃/PCBM/Perovskite/Fe₃O₄/PEDOT:PSS/Ag using a spin-coating method. Structural, optical, and electrical properties were characterized by X-ray diffraction (XRD), UV–Vis spectroscopy, and current–voltage (J–V) measurements. XRD confirmed the presence of distinct α-Fe₂O₃ and Fe₃O₄ crystalline phases, while UV–Vis analysis revealed enhanced absorption and a reduced optical bandgap of 2.04 eV. Devices incorporating both oxide layers achieved improved charge separation and interfacial contact, leading to a power conversion efficiency (PCE) of 0.83%, nearly 30 times higher than the reference device without oxide layers. These findings highlight α-Fe₂O₃ and Fe₃O₄ as promising low-cost, stable transport layers for enhancing the efficiency and sustainability of PSCs.

Abstract: In this work, the growth behavior of individual austenite grains of C45 alloy at 1000-1300 °C was recorded by in-situ SEM and austenite growth kinetics was analyzed. The result shows that the equivalent grain size and the annealing time conformed to the Beck relation, and the mechanism of grain growth is discussed. Based on the grain boundary migration theory, the relationship between triple junctions and the velocity of grain boundary migration is also considered, and the effect of grain boundary curvature on grain boundary migration is analyzed. The results indicate that it is not rigorous to rely only on curvature to describe the rate of grain boundary migration in polycrystal, and that the role of triple junctions has often been underestimated in previous studies of polycrystalline grain boundary migration.

Abstract: Gray iron remains the dominant material for automotive brake discs due to its excellent thermal conductivity, wear resistance, castability, and cost-effectiveness. To enhance its performance, this study investigates the effect of varying carbon equivalent (CE) on the thermal conductivity of titanium-alloyed gray iron. Four compositions with CE ranging from 3.89 to 4.77 were cast and analyzed. Microstructural examination revealed a transition from hypoeutectic to hypereutectic structures, with increasing graphite size and reduced dendritic austenite as CE increased. Thermal conductivity measurements, conducted using the Hot Disk Thermal Constant Analyzer, showed that higher CE improved thermal conductivity, attributed to the presence of larger graphite flakes and reduced primary austenite. These results indicate that optimizing CE in Ti-alloyed gray iron can significantly enhance heat dissipation in brake discs, offering improved performance without substantial cost increases.