Papers by Keyword: Alloy

Abstract: Hydrogen represents a promising clean energy carrier with exceptional gravimetric energy density (120 MJ/kg) [1]. Metal hydrides offer superior hydrogen storage through chemical absorption at interstitial sites, enabling performance optimization via alloy composition [2,3]. However, Mg-based hydrides, despite their high capacity, exhibit limitations including strong Mg-H bonding and sluggish kinetics, necessitating elevated dehydrogenation temperatures (600-700 K) [4,5]. Molecular dynamics (MD) simulations provide detailed atomistic insights into mechanical behavior under hydrogenation conditions [6]. This investigation employs MD to elucidate the effects of hydrogenation on the mechanical properties of Mg-Pd-Ni ternary alloys, aiming to identify compositions with enhanced structural durability for practical hydrogen storage applications.

Abstract: Aluminum-Air Batteries (AABs) are considered to be an attractive candidate as a energy storage technology due to their abundant raw material availability, high theoretical capacity, energy density, and safety. However, the development of these batteries is hindered by limited energy efficiency, primarily due to the high rate of self-corrosion of the aluminum anode in alkaline solutions, both under open-circuit conditions and during battery discharge. This research aims to enhance the performance of aluminum anodes in AABs by using commercials aluminum alloys as anodes and modifying their surfaces through the electrodeposition of zinc and manganese (Zn-Mn). The electrolyte used in this AAB is an alkaline solution consist of KOH 4M with 0,2M ZnO and 100mg/L CTAB as additive. The results show that electrodeposition was successfully conducted, leading to reduced corrosion rate as observed in linear polarization tests. Furthermore, electrodeposition contributed to increase battery cycle life, capacity discharge and energy discharge, as demonstrated by charge-discharge tests.

Abstract: Materials are a core part of the development in mechanical turbines, where there is always potential for life-improvement. The demand for alloys with durability, low cost, and long service cycles are evergreen. The materials used in turbomachinery must have excellent resistance to thermal fatigue, as well as high temperature oxidation and corrosion resistance. Good creep resistance is also an important consideration, especially for large blades and multi-airfoil latter stage nozzles. Development of new alloy compositions and material characterization plays a critical role in advanced machinery evolution. In this work, some of the available characterization methods are applied to analyze and study the effect of heat treatment, service effect and aging on alloys.

Abstract: Aluminum materials are used in a wide field for household appliances, aircraft, cars, ships, and construction. This research aims to obtain a new material based on aluminum magnesium silicon (AlMgSi) alloy as an alternative material to replace the steel base material in the shaft propeller product. In this paper, we will use the die-casting method to investigate corrosion resistance and the microstructure of the propeller shaft with AlMgSi aluminum alloy base material. The main base material used is 6063 aluminum alloy, with variations in the addition of Si (1, 2, 4 wt%). Alloy Al6063 is heated to a temperature of 720°C to reach a complete liquid state. Then the temperature is lowered to 645°C, then the Si element is inserted into the heating furnace and stirred. Then the temperature is lowered to 615°C, then the Mg element is added, then stirred thoroughly by a mechanical stirrer. The rotational speed of the stirrer is 70 rpm and the stirring time is 240 seconds. They were then heated to a pouring temperature of 680°C. The mold is heated to a temperature of 265°C. Then poured into the mold and pressed 7 MPa. The cast is cooled at room temperature. Then the casting products were heat treated with a solution treatment temperature of 485°C for 3600 seconds and quenched. After that, the casting products were treated with artificial aging. The results of this study show corrosion resistance increases along with the addition of variations of Silicon. The highest corrosion rate was obtained by adding Si as much as 4 wt% of 511.28 mm/y. With the addition of variations of Silicon 0 wt%, 1 wt% and 2 wt% showed the corrosion rate of 173.35 mm/y, 201.60 mm/y, 233.49 mm/y. The microstructure shows differences in grain structure. materials with variations of si 0 wt% and materials with variations of si 0 wt%, 1 wt%, 2 wt% and 4 wt% have different grain sizes. The intermediate phase (Mg₂Si) was mostly formed at Si 4% wt variation. So this study proves that adding silicon elements can increase grain sizes and refiner the propeller shaft.

Abstract: Innovation in the automotive field is now growing rapidly. New materials are considered to be incorporated in automotive design if they have economic and vehicle performance benefits. This research investigates the change of the Magnesium (Mg) addition and heat treatment to the mechanical properties and microstructure of the car chassis prototype with Al10Si Aluminum alloy base material. The process of casting using the High-Pressure Die Casting method. Variation of Mg (3, 4, 5 wt%) to increase the strength of mechanical properties of Al10Si aluminum alloy material. In the casting process, the first Al10Si heated up to 690°C. Mg is incorporated into the heating furnace, then stirred by a mechanical stirrer. Stirring speed of 90 rpm and stirring time of 120 seconds. After it has poured into the mold, the casting temperature is 740°C. Then cools the room to room temperature 39°C. Then performed, heat treatment, using the method of age hardening and artificial aging. The test results prove that the hardening heat treatment makes the grain size smaller. Small grain size, then increase the strength of the material with the addition of Mg elements.

Abstract: The effects of rare earth element Y addition on the structure, elastic modulus and hardness of Ti₈₀Nb_20-xY_x (x =0, 1, 2) alloys were investigated experimentally. The results showed that the structure of Ti-Nb-Y ternary alloys consist of the Ti-Nb matrix and Y-rich precipitates. Increasing the Y content can significantly improve the hardness and elastic modulus decreases with of Ti-Nb-Y alloys.

Abstract: The article describes the features of the casting process in the chill mold of magnesium alloys. The main factors affecting the quality of the castings obtained are indicated. The main defects of magnesium castings obtained by chill mold casting, as well as possible ways to eliminate them, are revealed. Options for improving the efficiency of the casting process by optimizing the process parameters are proposed, as well as options for heat treatment that increase the physical and mechanical properties of ready-made castings are presented.

Abstract: Copper-tin-zinc (Cu-Sn-Zn) ternary alloy coatings was successfully deposited from a less hazardous electrolyte containing copper (II) chloride, tin (II) chloride, zinc chloride, sodium hypophosphite and complexing agent. In this work, the impact of different complexing agent on morphology, chemical composition, current efficiency, microhardness, and corrosion rate were investigated by method of SEM equipped with EDX spectroscopy, weight gain measurements, XRD, Vickers microhardness test and potentiodynamic polarization measurement, respectively. It was discovered that, Cu-Sn-Zn alloys prepared using sodium formate shows the highest microhardness value. It is also can be concluded that, complexing agent have a significant impact on the appearance and the surface morphology of the Cu-Sn-Zn alloy electrodeposits.

Abstract: The development of modern high-tech industries of industrial production is impossible without the development of new methods for processing materials with high mechanical characteristics. There is a growing need for an increase in the proportion of parts made of aluminum alloys, a more complex configuration of cast parts, an increase in their reliability and durability in operation, etc. All this poses for metallurgists and foundry workers the task of creating new technologies for producing alloys, improving the technical and economic characteristics of structural materials, improving the quality and reducing the cost of castings.Hypoeutectic silumins have good casting properties, good weldability, machinability and corrosion resistance. However, they are prone to the formation of a coarse needle-like state, which reduces their useful characteristics. To eliminate this phenomenon, it is necessary to apply special technologies and the most common is their modification, which provides grain refinement. This makes it possible to use silumins for the manufacture of castings of complex shapes with increased density and low shrinkage porosity. Such parts can withstand average loads in critical units. Aluminum-silicon alloy AK7 or (ASi7Mg0.3) is a typical silumin, which is in demand in the automotive industry, construction, aircraft construction, machine, automobile and tractor production. It is appreciated for its good casting properties, weldability, machinability and corrosion resistance.

Abstract: The article deals with the role of electrodes materials in improving the industrial wastewater treatment from pollutants by electrochemical action. The instability constants of the complexes and coordinated ligand molecules were calculated. Based on the research conducted regarding the rationalisation of the poly-ligand electrolytes and electrolysis modes, a variative flow scheme of the coatings deposition by triple alloy has been developed. The corrosion resistance characteristics of the coatings obtained in the form of alloy, that were obtained from complex electrolyte that satisfy the necessary coatings requirements for effective treatment of wastewater have been researched. The obtained coatings have better corrosion resistance than in special steels of electrochemical purpose.