Materials Science Forum Vol. 1177

Abstract: In regard to shaping up a complex-shaped, largely strained industrial forming part, sheet hydroforming (SHF) is one of the primary processes utilized to address these challenges. Before actual tooling fabrication, the finite element (FE) simulation is, nowadays, commonly employed to assess the feasibility of the process and tooling design. Therein, material modelling, especially of the distinguishing deformation anisotropy unavoidable in cold rolled sheet metal, plays a vital role. This study, therefore, seeks to enhance the capability of the FE simulation on sheet hydroforming of an SPC270 mild steel sheet comparatively through the von Mises, Hill’48, and Yld2000-2d yield criteria. Additionally, the hybrid Swift-Voce (HSV) model is applied to refine and extend the experimentally determined uniaxial flow stress curve. The prediction accuracy is evaluated on the basis of two geometrical deviations such as the sheet thickness distribution and tank surface profile. The results show that the Yld2000-2d yield model obviously leads to the most accurate geometric estimation for both evaluation criteria.

Abstract: In the highly competitive situation of die-making, the importance of improving die production process efficiency is highlighted. However, complex sheet metal forming processes often encounter springback issues, which can impact dimensional accuracy and increase die tryout iterations. To address this challenge, this research develops the so called “full-cycle simulation” by which multi-stage forming process simulation is iteratively performed along with the JSTAMP’s auto-compensate functionality to enhance the die design performance. The innovative simulation technique is applied to perform the forming process simulation of an automobile hood outer panel made from the AA6000-IH-E aluminum alloy. The Hill’48 yield criterion is employed to accurately capture the anisotropic deformation behavior of the material. Two full-cycle simulations are conducted under the same material and boundary conditions but different die design concepts. The results demonstrate significant improvement in the draw-in profile, sheet thinning distribution and springback reduction, compared to any straightforward forming process simulation. The model, incorporating the lighter die design concept, outperforms the other model in all aspects. It is therefore put into practice. An accurate physical hood outer panel is eventually realized.

Abstract: This research demonstrates the production of membranes utilizing polyethersulfone (PES). Cellulose Acetate (CA) at 5% and Polyethylene Glycol (PEG) at 5% are incorporated into the PES membrane as additives, while ethanol serves as a variable non-solvent in the coagulation bath. The incorporation of CA and PEG additives serves to enhance the performance and characteristics of PES membranes. Fabrication of PES membranes utilizing the non-solvent induced phase separation (NIPS) technique. The impact of additive incorporation was assessed through various characterization tests, including Swelling degree, Tensile strength, contact angle, Scanning Electron Microscopy (SEM), and Fourier transform infrared (FTIR). The results indicated that the swelling degree value increased from 13.66% (PES) to 39.40% with the addition of PEG and CA. Nevertheless, the membrane's mechanical strength was diminished as a result of the inclusion of PEG. PES/CA exhibits the highest tensile strength value at 1.8 MPa, while PES/PEG has a peak of 1.4 MPa. The optimal contact angle measurement was achieved on the PES/CA/PEG membrane at 50°. The SEM characterization results indicated an increase in membrane pore size, with the modified membrane exhibiting a pore size range of 0.331-0.664 μm. The incorporation of 60% ethanol as a non-solvent resulted in the maximum swelling degree value of 41.05%. In conclusion, the characteristics of the membrane are influenced by the combination of additive Cellulose Acetate (CA) and Polyethylene Glycol (PEG) through blending.

Abstract: As the demand for energy and technological advancements continues to grow, the need for efficient and high-capacity energy storage devices is also increasing. Supercapacitors have emerged as a potential solution, offering advantages such as high specific capacitance, shorter charging times, and longer lifespan. Metal-Organic Framework (MOF) materials have shown promise potential as various electrodes applications due to their superior surface area and porosity. This study focuses on the development of MOF materials based on HKUST-1 with bimetallic modification at a 1:1 ratio, using cobalt and nickel as the metal center. The synthesis, characterization, and electrochemical testing were conducted to evaluate the potential of each material as an electrode for supercapacitor applications. The synthesis was carried out using the coprecipitation method. SEM and XRD characterizations revealed poor crystallinity, with a morphological change to polyhedral shapes with the addition of Ni and elongated shapes with the addition of Co. Electrochemical tests using cyclic voltammetry and galvanostatic charge discharge techniques demonstrated poor supercapacitor performance, with non-ideal voltammetry curves and relatively low specific capacitance compared to common supercapacitor materials. The trend shows that secondary metals improves the characteristics of HKUST-1 as supercapacitor. It is shown that the HKUST-1 which has been added with Co and Ni is better than regular HKUST-1, with Co being the best out of all three. This trend is also supported by DFT calculations which shows stronger adsorption in Co active sites, followed by Ni and lastly Cu.

Abstract: This work aims to evaluate the effect of extraction methods for Grewia bicolor (GB) fiber in the reinforcement of a biosourced material with a Detarium Microcarpum (DM) tannin matrix. GB fibers were extracted by biological retting and chemical extraction in sodium hydroxide (NaOH) solutions at concentrations of 2% and 5%, respectively, and sampled from three plant zones: bottom, middle, and top. These different fiber families were physically characterized (moisture content, water absorption, density) and mechanically tested under tensile loading, followed by multivariate statistical analysis using Multivariate Analysis Of Variance (MANOVA). Tannin extracted from DM bark was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-ToF) mass spectrometry, and its reactivity with formaldehyde was evaluated. A biosourced resin was then formulated using DM tannin and Acacia nilotica as a natural hardener. This resin was characterized by measuring hydrogen potential (pH), dry extract, and gel time. Composite panels were produced by combining the formulated resin with the various fiber families at a 30% reinforcement rate. These composites were characterized physically (water absorption, thickness swelling, density) and mechanically in terms of modulus of elasticity (MOE), modulus of rupture (MOR), and internal bonding (IB) strength. The results demonstrated that fibers extracted with 2% NaOH provided the best overall performance. MANOVA combined with Tukey's test at a 95% confidence level showed statistically significant differences among the extraction methods but not between the bottom and middle fibers regardless of the method. The characterization of DM tannin showed its potential use in resin production. The performance of the composites manufactured was better than those made with the fibers extracted in the 2% NaOH solution, showing that GB fibers and DM tannin are promising local resources for the production of furniture panels working in a dry environment in compliance with the requirements of NF EN 312.

Abstract: This study investigates the potential of typha domingensis fibers to be used as reinforcement in composite materials. Morphological, mechanical, and thermal analyses were conducted on fibers extracted from leaves and stems using various methods. The leaf fibers (LNF-00, LRD-41, LRS-41), with transverse dimensions ranging between 185 to 244 µm, were on average 48% thinner than stem fibers (SNF-00, SRD-20, SRS-20), whose transverse dimensions ranged from 305 to 334 µm. Transverse dimensions variations were most pronounced for fibers retted in distilled water (65%), followed by those retted in seawater (47%) and mechanically processed fibers (37%). Stem fibers subjected to seawater retting (SRS-20) exhibited less dispersion in mechanical properties, with a Young’s modulus of 2.2 GPa and a tensile strength of 55.9 MPa. Overall, leaf fibers outperformed stem fibers, with average increases of 38, 60, and 31% for Young’s modulus, tensile strength, and elongation at failure, respectively. Finally, thermal analysis revealed that fibers retted in distilled water provided the highest thermal stability, attributed to a reduction in lignin and hemicelluloses.

Abstract: Sugarcane bagasse which is generally only wasted or burned after the sugarcane extracted will cause environmental pollution. Sugarcane bagasse contains fibers that can be used as reinforcement in composite materials. Utilization of sugarcane bagasse fiber made into particle board composite material in addition to reducing waste is also an added value of the waste itself. Alkalization treatment of sugarcane fibers with NaOH solution at concentrations 3%, 5% and 7% was carried out to modify the surface to improve the bond between fibers and epoxy resin. The alkalization results were tested for bending properties to see the effectiveness of fiber treatment. The best treatment is added basalt powder as a material that has heat resistance with different sizes of mesh 100, 200, and 325 to make particle board composites. The particleboard composites were tested for flammability, bending properties and strength. The results show that treatment with NaOH solution is quite effective in improving fiber and resin bonding as evidenced by the results of the bending test which increased significantly by 179% after NaOH treatment compared to without treatment. Treatment with 5% NaOH showed the best bending strength 15.40 MPa. After adding basalt powder even though it has not been able to stop the flame but the rate of flame propagation is reduced from 27.37 mm/min to 20.90 mm/min, this indicates that basalt powder works but not yet optimal. Bending and compressive strength increases when basalt powder is added compared without basalt, getting smaller basalts size the strength increases. Composites made from sugarcane bagasse fibers, basalt and epoxy resin have potential to reach the minimum standard of mechanical properties for particleboard applications.

Abstract: Mycelium-based composite (MBC), as a new engineering biocomposite, is receiving numerous interests due to its environmental sustainability. The study aimed to address the challenge of optimizing the physical properties of MBC for a more efficient production process. The study investigated the impact of hot or cold pressing, different pressing temperatures (120 °C, 160 °C, and 200 °C), pressing pressures (low, medium and high) and sequences (before and after drying process) on the physical properties of MBC such as density, shrinkage, moisture content and hardness. Mycelium millets were mixed with kenaf, carbon carbonate, wheat bran and wheat flour. The pressing methods and sequences significantly affected the properties of the MBC. Cold pressing had no effect on reducing shrinkage and moisture content of MBC but improved density. Hot pressing increased hardness at higher temperature and pressure, with strong mycelium-substrate bonding and less porosity observed in SEM image. The post processing sequence involving drying followed by hot pressing at 200°C exhibited higher density, hardness, less shrinkage and controllable moisture content of MBC for better dimensional stability and quality control purpose. It was crucial to optimize MBC pressing techniques for specific applications and ensure that it satisfied the demanding standards of companies looking for sustainable alternatives and cost-effective production.

Abstract: Hydrogen, a zero-carbon energy source with high energy density, is widely used in Proton Exchange Membrane Fuel Cells (PEMFC), where Membrane Electrode Assembly (MEA) plays an important role. This study examines the fabrication of MEAs using the Catalyst Coated Membrane (CCM) technique by airbrush spray and ultrasonic spray methods, using Pt/C catalysts on activated carbon from kepok banana peel (soft carbon) and carbon nanotubes (CNT). Activated carbon soaked with 1M NaOH for 3 hours showed a surface area of 163.075 m²/g, exceeding that of CNTs (101.466 m²/g). The Pt/C catalyst with 1M3H-1 configuration achieved the highest Pt content (52.99 wt%). The ultrasonic spray ensured an even distribution of the catalyst, with a power density of 0.167 mW/cm² (1M3H-1) achieved faster. Although the airbrush spray reaches 0.889 mW/cm² (CNT1), the time required is longer, making the ultrasonic spray more efficient.