Papers by Keyword: Bimetallic

Abstract: This study uses numerical simulation to examine the influence of variations in laser power and transition zone length on the tensile behavior of bimetallic samples designed to be manufactured by selective laser melting (SLM). The materials studied are 316L stainless steel-copper, chosen for their complementary mechanical properties and functional relevance in high-stress applications. The transition between the two materials was modeled by modulating the laser power according to different profiles (linear, concave or convex) and over different lengths (d(x) = 0 mm, 10 mm, 20 mm) in order to evaluate their impact on the simulated mechanical performance. The numerical results show that a gradual transition in laser power, combined with an extended transition zone, significantly improves stress distribution and leads to better mechanical integrity. Simulations performed in ANSYS provide an in-depth analysis of stress fields and highlight the crucial role of manufacturing parameter management. This study thus highlights the importance of precise control of manufacturing parameters in the 3D printing of bimetallic components and demonstrates, through numerical modeling, that optimized transition management can improve the mechanical integrity of parts produced by SLM. Experimental validation of these results will be an essential prospect for future work.

Abstract: An electrical insulator known as a dielectric material is a substance that can be solid, liquid, or gaseous. Having a high specific resistance, a dielectric material is a non-metallic substance. A dielectric function as the perfect capacitor, storing and dissipating electrical energy. Due to the rising need for capacitors, semiconductor devices, Liquid Crystal Displays, electrical transformers, and other products, properties including electric susceptibility, dielectric polarisation, dispersion, relaxation, and tunability have received a great deal of attention. Advanced materials must be developed in order to further enhance their performance. Metal-organic frameworks (MOFs), a class of porous crystalline solids, have shown to be ideal models for synthesising functional materials that may be used to make supercapacitor electrodes. Greater electrical conductivity, a higher charge capacity, and variable electrochemical activity are just a few benefits that bimetallic MOFs and their derivatives have over monometallic MOFs. This study focuses on the usage of MOF-derived bimetallic in dielectric materials, with particular attention paid to understanding the cause of the enhanced performance and covering the most recent advancements in the area with a variety of applications.

Abstract: — The catalytic oxidative desulfurization (Cat-ODS) process has been introduced as a new technology to achieve ultra-low sulphur levels in diesel fuels. In this study, the performance of the alumina supported iron oxide based catalysts doped with cobalt, synthesized via wet impregnation method on the Cat-ODS of the model diesel with the total sulphur 500ppm was investigated using tert-butyl hydroperoxide (TBHP) as an oxidizing agent and N,N-dimethylformamide as an extraction solvent. A series of dopant was being screened. Co/Fe-Al₂O₃ (10:90) and Co/Fe-Al₂O₃ (20:80) prepared at 400°C. Overall, the catalytic activity decreased as dopant ratio increased. Catalyst with 10 wt% of Co was successfully removed 96% of thiophene, 100% of DBT and 92% of 4,6-DMDBT in model diesel. Further investigation, potential catalyst that calcined at 400°C contributed higher sulphur removal compared to the catalyst calcined at 500°C. X-ray diffraction analysis (XRD) result showed that Co/Fe-Al₂O₃ (10:90) prepared at 400°C was amorphous, while micrograph of the field emission scanning electron microscopy (FESEM) illustrated an inhomogeneous distribution of various particle sizes. The energy dispersive X-ray analysis (EDX) result have confirmed the presence of Fe and Co in all of the prepared catalyst.

Abstract: The purpose of this study was to investigate (simulation of environment for salt treatment of roads in winter and the simulation of the environment of condensed exhaust gas) the galvanic corrosion phenomena which can exist in the construction coupling of cars. The electrochemical behaviour of the hot dip galvanized steel and aluminium alloy, stainless steel and aluminium alloy and stainless steel and silumin which were investigated by electrochemical methods in 3 % NaCl solution and in SEG solution. The open corrosion potential measurement was used to obtain the values of the potential for each couple. The measurement showed a greater bimetallic risk for hot dip galvanized steel with aluminium alloy, where there was ΔE_SCE > 500 mV and this couple is not suitable either for use in aggressive environment. Calculation of the rate of corrosion attack results from the determination of corrosion currents as measured by Taffel and Evans. The extent of corrosion damage was analysed by means of a light microscope. Keywords: bimetallic; aluminium alloy; stainless steel; silumin; exhaust gas; corrosion potential; electrochemical method;

Abstract: The knowledge of elastic fields caused by dislocation networks is a network that is sometimes indispensable for the interpretation of images obtained by electron microscopy and for the understanding of physical phenomena. In this axis, the present work makes it possible to determine the elastic behavior of a thin bimetallic isotropic elasticity in the case where the hetero-interface is covered with a parallel network of wedge type detuning dislocations. The topology of the free surfaces is calculated according to the total thickness of the bimetallic strip until a relaxation is reached for a thickness "h" called critical thickness.

Abstract: Light weight aluminium alloys and low-density materials have drawn the attention of researchers as potential structural materials for transportation sector due to the requirement of effective reduction in fuel consumption, stringent emission norms and higher payload capacity. Functionally Graded Materials (FGM) provides variation in properties and better functional performance within a component. Sequential casting is fairly a new technique to produce functionally graded materials and components by controlled mould filling process. Bimetallics of aluminium alloys are prepared by sequential casting using A390-A319 alloy (cast-cast alloy) and A390-A6061 alloy (cast-wrought alloy) combination and solidified under gravity. The effect of temperature of the two melts and gap between pouring of the melts on microstructure and properties of the bimetals are investigated. The microstructures show good interface bonding between the two different alloy metals. The hardness testing shows higher hardness at hypereutectic alloy region. The process described in this study shows potential and effective approach to create good bonding between two different aluminium alloys to develop advanced functional and structural materials which can be used in various automobile components to reduce the overall weight of the vehicle, by which better fuel efficiency and performance can be achieved.

Abstract: Bimetallic castings are widely employed as working elements in winning machines which work in conditions of intensive friction wear. The main features of wear are: dynamic percussive loads, intensive abrasive wear caused by erosion and corrosion. Three cylindrical rods cavities of the same dimensions of φ 20x200 mm were made in sand mould. Different amount of liquid iron alloy with carbon equivalent of 4.14, Mn of 0.58 and Cu of 0.17 wt% was poured into the three rod cylindrical cavities over the solid 304 stainless steels cylindrical desks inserts. Good coherent interfaces for all liquid/Solid volumes (16 to 24) are produced and multi-layers interfacial microstructure bimetal are produced. Increasing the liquid/solid volumes from 16 to 24 increases the thickness of transient layer from 52 to 89 μm and decreases the amount of ledeburite in the structure of solidified gray cast iron.

Abstract: Nowadays, ultraviolet (UV) irradiation heterogeneous Fenton-like reactions have widespread used in organic wastewater treatment. In this paper, Fe²⁺ and Cu²⁺ were load in Na-Y molecular sieve using impregnation method. Fe-Y, Cu-Y and Fe-Cu-Y catalysts were obtained. The Fe-Cu-Y catalyst showed good performance in the degradation of 6-nitryl wastewater. When the volume of 6-nitryl wastewater is 100 mL, the optimal reaction conditions were found to be 3mL of hydrogen peroxide, 7.5g of catalyst weight, 250W of UV power. Under these conditions, the degradation rate of COD_Cr can be up to 97.0%.

Abstract: Present heat exchangers should ensure very good heat transfer while having as small size, high durability and the optimum performance at low prices. Thus to achieve these goals is used as base material, aluminum in various forms, of which can be made the heat exchangers energetic efficient. Realization of aluminum heat exchangers can be properly with present requirements using the brazing joint elements. Brazing achieved joining with temperature for two base materials using a filler metal with a melting point above 450°C. A properly brazed joint is performed with a metallurgical connection between two or more metals, which is generally as strong as or stronger than the base metal used.

Abstract: In this paper we propose to analyze drawing of bimetallic sheets joined by brazing. Drawing is the transformation of a plan workpiece to the drawn part or workpiece transformation with decreasing of depth corresponding transverse dimensions. The brazing process is based on the difference in the melting points of the base materials and filler metal. During the brazing process, the bimetallic sheets to be assembled are heated for at a temperature between the melting temperatures of the two alloys, this process tends to modify the geometry and the microstructure of the brazed sheets.