Key Engineering Materials Vol. 990

Abstract: The implementation of Industry 4.0 is based, among other things, on the digitization and greening of manufacturing systems. Most traditional manufacturing systems are known for low productivity and efficiency. They are also known for the impact they have on the environment, with relatively high carbon footprints. The paper transfers a series of knowledge on the steps to be taken to transition a traditional manufacturing system to a digitized and green one. Customization of this discussion is done for manufacturing systems that have joining processes (welding and soldering). Each set of measures, whether aimed at the transition to digital or aimed at the transition to green, has two components: a technical component, directly related to the transformation of the hardware system (equipment, devices, measuring instruments) and a component auxiliary which is related to the transformation of the human resource, the modification of the working conditions and the continuous optimization of the newly created system. As no change is possible without removing employee misunderstandings and suspicions, the communication to be implemented must be clear, prompt, cover all levels of staff and continuously provide confidence by presenting successful cases and related beneficial figures.

Abstract: The purpose of this paper is to study the strength characteristics of V4 resin components that are welded using ultrasonics. These components are created using the Low Force Stereolithography (LFS) technology, which reduces the printing forces for achieving the best possible finish. Welding components are 3D printed with a Form 3+ 3D printer, known for its high printing precision, employing a powerful laser and a spatial filter. Key characteristics of the ultrasonically welded components can be extracted, analysed, and summarized to provide guidance on the optimal resin selection.

Abstract: Designing and manufacturing a new mold is laborious work and requires well-trained human resources but also considerable material investments. The achizition and implementation the CAD/CAM softwares, three and five-axis machining centers, cutting tools with high performance are necessary to processing a mold. That is why it is frequently used to repair used molds. This repair is done by welding and then manufacturing on machines with numerical control. The present paper presents these stages of corrective maintenance of a mold. Starting from a concrete case, the solutions for remediation of the used mold are presented. The two basic operations in retrofitting, welding and computer-assisted processing on CNC machines are also analyzed.

Abstract: This paper presents a finite element modeling procedure to determine of crack growth behaviour of butt welded joints under the subject of load for mode I. This paper presents a computation procedure to determine the ratio of fatigue crack growth in butt welded plates for mode I fracture mechanics loading conditions. The presence of residual stresses in welded structures can significantly affect the material’s resistance to fatigue under cyclic loading. The presence of tensile residual stresses adversely affects the fatigue crack growth rate increased it. Change of microstructure and hardening material as a result of the welding process also has a negative impact on the growth of the crack. Accurate prediction and reliable assessment of the residual stress are important for the structural integrity and residual life assessment of welded parts design. Although there are several techniques for the determination of residual stresses, the finite element method (FEM) is one of the most convenient and useful. This paper presents a finite element modeling procedure to determine of crack growth behaviour of butt welded joints under tensile load for mode I. Keywords: Welding, Residual stress, Residual life, Crack growth, FEM, Butt welded joint

Abstract: Industrial requirements to establish metallic joints between dissimilar metals in the electric area. The ultrasonic welding process is an optimal process to joint thin sheets or foils. The goal of the research was to optimize the ultrasonic welding parameters to join thin nickel-coated copper sheets and aluminium sheets. It used a 0.5 mm thick high-purity copper (Cu-OF-R200) sheet coated with a 10 μm pure nickel layer and a 0.5 mm thick aluminium (1050A H24) sheet. The ultrasonic welding is made by a Branson Ultraweld L20 ultrasonic welder equipment. The mechanical properties and exacting geometrical tolerance of the joint were required. The welding parameter optimization is made empirically, with several welding tests. The optimal welding parameters were confirmed by non-destructive and destructive tests of the joints. The non-destructive tests were the visual inspection and geometrical measurements of the joint sizes. The destructive tests were tensile tests and macroscopic and microscopic tests. The completed test results confirmed the process applicability and the quality of the joint.

Abstract: This work only investigated the x-direction scanning of atomic force microscopy, which can accurately measure porous silicon's width, depth, and roughness. Pores on p-type Si (100) surfaces fabricated by electrochemical anodization method with the variation of resistivity and current density, i.e., 0.001-0.005 Ω.cm (high dopant) and 1-10 Ω.cm (low dopant), and 4, 6, 8, and 10 mA/cm², respectively. Macroporous silicon was obtained for both high and low dopants. Pore width, pore depth, and roughness of silicon increase with increasing the current density. Characteristics of porous silicon for high dopants are smaller than that for low dopants. It indicates that large amounts of dopant in silicon can slow the etching process.

Abstract: Imprinted ionic synthesis through the sol-gel process for Ni (II) adsorption has been carried out. Sodium silicate from rice husk ash (NaSiO_3(RHA)), N¹-(3 Trimethoxysilylpropyl) diethylenetriamine (TMPDT) and Ni (II) are stirred, then 6 M HCl is added until a gel forms. Furthermore, 0.1 M EDTA and 0.1 M HNO₃ were added to the dry gel to release Ni (II) to form-imprinted ionic material (SiO₂-TMPDT-Ni-Imp). The material was characterized using FTIR, SAA, and SEM-EDX. FTIR characterization of SiO₂-TMPDT-Ni-Imp indicated the appearance of-OH, -CH, -Si-O-and-NH absorption. The SAA characterization results show a surface area of 18.091 m2/g, a total pore volume of 0.033 cc/g, and an average pore radius of 16.739 Å. The optimum conditions for Ni (II) adsorption by SiO₂-TMPDT-Ni-Imp are pH four and a contact time of 100 minutes. The appropriate adsorption kinetic model for the absorption of Ni (II is pseudo-second order with an adsorption capacity of 6.9 mg/g. Keywords: Silica, imprinted ionic, rice husk ash, adsorption, Ni (II)

Abstract: The use of mesoporous material as a carrier is increasingly gaining significant attention in recent years. The carrier often exists in the form of organic polymers, including chitosan and starch-g-poly (L-lactide), as well as inorganic substances, namely zeolites, sulfur, and silica. In this context, silica has the greatest abundance in nature and is extensively applied as a carrier medium due to its high selectivity, excellent regeneration ability, and environmental friendliness. However, this material shows some limitations, such as high surface tension and large inter-particle bonding forces, which can be addressed through modifications of the surface area and pore size by adding surfactants. The modifications will transform silica into a mesoporous structure, suitable for use as a slow-release carrier in various applications, including catalysts, sensors, adsorbents, chromatography, drug delivery systems, and intelligent corrosion inhibitors.

Abstract: Emissions are substances that enter the air, whether or not they have the potential as pollutants. Emission gases can have adverse effects on the health of living beings, especially humans, and can contribute to an increase in the Earth's temperature. Therefore, separation efforts are needed to minimize the negative impacts caused by them. Adsorption method was categorized as absorption, cryogenic distillation, and membrane. Although there were shortcomings in adsorbing emission gases through the method, it remained a promising approach. Adsorption was recognized for its economic viability, technological effectiveness, thermally stability, corrosion resistance, high load capacity, and tunable surface properties. However, adsorption materials were categorized as porous carbon, zeolites, metal-organic frameworks (MOFs), porous polymers, and porous silica. A significant limitation of the method was its susceptibility to decreased capacity in the presence of water vapor. The analysis results showed that porous silica became a superior adsorption material due to its high porosity, which facilitated rapid gas diffusion. To enhance selectivity and adjust pore size, material modifications, particularly silica, became necessary. This showed that surface modification for silicasupported the improvements in selectivity and pore size.