Diffusion Foundations and Materials Applications Vol. 35

Abstract: Polymer-metal hybrid nanocomposites have garnered significant attention in recent years due to their exceptional electrical and dielectric properties, which find applications in a wide range of industries, including electronics, energy storage, and advanced materials. This review article provides a comprehensive overview of the current state-of-the-art in the field of polymer-metal hybrid nanocomposites, with a particular focus on their electrical and dielectric properties. The first section of the review delves into the synthesis and fabrication techniques employed to create these nanocomposites, highlighting the importance of controlling the dispersion and distribution of metal nanoparticles within the polymer matrix. Various approaches, such as in-situ polymerization, melt mixing, and electrospinning, are discussed in detail, along with their respective advantages and limitations.The subsequent sections explore the influence of metal nanoparticles on the electrical conductivity and dielectric constant of the nanocomposites. The role of factors such as nanoparticle size, shape, and concentration in determining these properties is thoroughly examined. Moreover, the impact of metal surface modifications and the choice of polymer matrix on enhancing electrical and dielectric performance are also addressed. In addition to discussing fundamental aspects, this review highlights practical applications of polymer-metal hybrid nanocomposites in the development of high-performance capacitors, sensors, electromagnetic shielding materials, and flexible electronics. The potential for these materials to revolutionize various technological sectors is discussed, emphasizing their role in advancing miniaturization, energy efficiency, and durability. Furthermore, the review outlines current challenges and future prospects in the field, including the need for a deeper understanding of the underlying mechanisms governing electrical and dielectric behavior in these nanocomposites. Emerging trends such as the incorporation of 2D materials and the development of multifunctional hybrid systems are also explored, hinting at exciting avenues for further research and innovation. In conclusion, polymer-metal hybrid nanocomposites offer a promising platform for tailoring electrical and dielectric properties to meet the demands of modern technology. This review serves as a valuable resource for researchers, engineers, and scientists seeking to explore the potential of these materials and drive advancements in the field of electrical and dielectric engineering.

Abstract: Wire-arc additive manufacturing is a method of 3D printing metal using welding techniques. However, due to heat, the mechanical properties of the deposited material may be affected. Various methods have been proposed to mechanically improve the properties. In this study, cold deformation was introduced to enhance the properties. The effects of a few parameters, including welding speed, wire feed rate, heat input, thickness ratio, and types of material, were studied. Based on the result, the hardness, tensile, and wear properties of the manufactured part improved, while other properties, like impact toughness, had a lower value. Based on the preliminary result, cold deformation shows potential alternatives for part repair or reconstruction of worn or broken parts.

Abstract: This research investigates the part distortion of WAAM process by utilizing advanced numerical simulation. The WAAM component is made of a stainless steel SS316L deposition layer that is deposited on top of a mild steel S235 substrate plate to create a hollow, rectangular structure with a thin wall. In this study, Goldak's double-ellipsoid was used as the heat source model, and an isotropic hardening rule based on the von-Mises yield criterion was used. MSC Marc/Mentat is utilized as the numerical FE software for this research. The commercial S235 mild steel for substrate and the evolved SS316L was scanned by JMATPRO as the input for material modelling. In order to reduce the computational time of the numerical WAAM process, an Inherent Strain Method (ISM) is proposed for a numerical WAAM simulation in Marc. There are two ISM methods proposed for this study, the first is the analytical ISM based on the calculations and second is the calibration-based ISM using Virtual Calibration Test (VCT). On obtaining the ISM value based on the result of VCT, the mathematical software MATLAB were utilized to find the optimized ISM value. This research has a final purpose to determine which numerical simulation model that has a clear advantage on predicting the component deformation result in term of result accuracy as well as computational time. The expected final outcome of this study is the implementation of ISM method on numerical WAAM simulation is able to predict a part distortion in an accurate manner similar to TMM model with significantly faster computational time. Keywords: WAAM, Part Distortion, Numerical Simulation, Inherent Strain Method, Computational Time.

Abstract: This work is devoted to the analysis of the influence of the triaxiality factor and the Lode parameter on the ductile fracture of a stainless steel tube. A micromechanical-based model incorporating several deformation mechanisms and formulated in the framework of the dislocation density theory is chosen to model the viscoplastic behavior of the 316L stainless steel. After adaptation of the implementation of the model into the finite element code Abaqus 2020 and the calibration of the model parameters with experimental available results, simulations of healthy and notched tubular specimens were carried out. In order to vary the triaxiality and Lode angle, we used specimens of different sizes and notch shapes. The results showed the capacity of the model to reproduce the experimental results of tubular structures. It was found that the strength and ductility of the specimens depend on the Triaxiality Factor and Lode Parameter.

Abstract: In the present study, titanium dioxide (TiO₂/Chitosan) nano-particles layer coatings were fabricated by electrophoretic deposition on 316 Austenitic Stainless steel substrate. Aims to enhance antibacterial properties by coating the surface with a bio ceramic (TiO₂) nano-powders. TiO₂, were made on 316 austenitic stainless steel substrate with an EPD (electrophoretic deposition) technique, charged particles suspended in ethanol at a concentration of 50 g/L, for each powder with ideal conditions of 20V and a deposition time of (2, 4 and 6 min). The surface tests of coated substrates, such as, micro-hardness, surface roughness and wettability antibacterial test were evaluated and compared to that of the uncoated substrates. The showed results the electrophoretic deposition is a favorable technique to make a bio coating on 316 Austenitic Stainless steel substrate with excellent properties and structure for applications biomedical. The results demonstrated that the coated sample under coating conditions (20V, 2min) which is close to the ratio found in living bone. the average micro-hardness of the TiO2 coated sample is 1483 HV compared with that of uncoated substrates is 460 HV. The results also of the wettability test showed that the contact angle of the deposited paint is 5.9 degrees, and this positive result is useful for biomedical applications and proved that the coating is hydrophilic.

Abstract: In the present study, (TiO2/HAP) and TiO2 coatings were fabricated with electrophoreticdeposition on substrate for titanium alloy. This study aims to increase improve this alloyantibacterial properties by coating the surface with a bio ceramic (TiO2 and TiO2/HAP)nano-powders. Coating on Ti-6Al-4V with an electrophoretic deposition(EPD) technique,ideal conditions of 20V and a deposition time of (4 min). The surface properties of coatedsubstrates, such as, micro-hardness, surface roughness and wettability antibacterial test wereevaluated and compared to that of the uncoated substrate. The results showed that theelectrophoretic deposition is a favorable technique to make a bio coating on Ti-6Al-4Vsubstrate with excellent properties and structure for applications biomedical.The average micro-hardness of the TiO2/HAP coated sample is 1024 HV compared withthat of uncoated substrates is 80 HV. The average thickness of TiO2/HAP coating isdetermined to be (18µm) on the substrate surface at factor deposition time (4 min). The resultsof previous research indicate that the high wettability and surface roughness at the micronscale were for the synergistic effect of reduction on cell adhesion and growth.