Papers by Keyword: Alloys

Abstract: In today's changing times, more and more people will use automobiles to get around, and this will consume a lot of natural resources to supply cars, in order to make energy efficiency, reducing the overall weight of the automobile is a direct way to reduce the weight of the automobile, and we need to use materials that can make the weight lighter while maintaining a certain level of strength. This review paper explores the properties of five custom materials: aluminum alloys, magnesium alloys, titanium alloys, carbon fiber, and ceramics. By comparing specific strengths and fatigue resistance, researchers found that customizing aluminum alloy are the most suitable materials for improving energy efficiency and reducing total vehicle weight, while still maintaining a certain level of stiffness. According to the data on the specific strength and fatigue resistance of aluminum alloy, it reaches conclusion that custom aluminum alloys can be used in the design of automotive vehicles as a function of improving fuel efficiency by reducing weight.

Abstract: The development of tailored alloys is an important aspect for enhancing efficiency across diverse applications in mechanical engineering. The use of computer-aided modelling offers an opportunity to enable a more efficient and targeted material development. In the present work, new iron-based alloys with specific properties were developed using the CALPHAD method. The alloy design developing process was carried out by using the simulation software JMatPro® and the data evaluation software EDA®. Using a full factorial plan, various alloys were modelled on the basis of the elements iron, nickel, vanadium, carbon, niobium and chromium. Afterwards, the alloys were narrowed down with regard to the criteria of carbide phase content, formability, and corrosion resistance. Subsequently, two final alloys were chosen based on their properties. Afterwards the selected final alloys were produced by mechanically blending different powder alloys and elements. These alloys were welded onto unalloyed steel using Plasma Transferred Arc welding and were characterised by using x-ray diffraction, scanning electron microscopy, hardness measurements, spark spectrometry and metallography. Subsequently, a verification of the welded samples regarding to chemical composition, phases, and corrosion resistance was carried out. The investigations showed that it was possible to simulate alloys with specific properties using computer-based software, which corresponded with the experimental studies.

Abstract: In this work, the preparation and processing of aluminum-copper alloys, which added amounts of copper to aluminum in different parentages (2, 4, 5%) so that it does not exceed the saturation limit for aluminum (6% Copper). After adding these specific amounts of copper to aluminum, have been melting each alloy to thaw copper in aluminum fully and diffusion copper atoms in it, and after that the specimens were prepared and quenched at 8-30 hours and rapid cooling in the water, and then were studied parameters of heat treatment and different percentages of copper. It is clear from the schemes and experimental results that each weight ratio of copper in aluminum has a different approach to reach the best mechanical properties. After performing mechanical tests and tests, it was found that the highest hardness of the (aluminum-copper) alloy in the case of (2% Cu) amounted to (120 HB) and in the case of (4% Cu) the amount (211 HB) and in the case of (5% Cu) the amount (188 HB).

Abstract: Aluminum with –2.5wt.% Cu–2.5wt.% Mg – 5wt.% Zn alloy was synthesized by die cast and spray formed technique. The average density of die cast and spray formed Al alloy was measured by water displacement method. The compression strength, hardness and tribological properties of the Al alloy produced by die cast and spray formed technique was studied as per the ASTM test standards and recorded the average values. The surface morphology of die cast Al alloy depicts the dendritic structures and spray formed Al alloy contains the equiaxed grains, coarse grains and fine grains across the surface. The elemental analysis of both die cast and spray formed Al alloy was measured by using scanning electron microscope. Average percentage of porosity of die cast and spray formed aluminum alloy is 1.79 ± 0.23 and 1.10 ± 0.3 respectively. The hardness of spray formed Al alloy is 10.54 % lesser than that of die cast Al alloy. Average ultimate compression strength of spray formed and die cast Al alloys are 360.07 ± 9.58 MPa and 353.33 ± 5.56 MPa respectively. The study also recorded the wear rate and coefficient of friction of die cast and spray formed Al alloy at different load and speed conditions. The precipitation strengthening mechanism is found to be involved in spray formed alloy.

Abstract: Seven multiphase YNi₃ and YN₄ based alloys have been prepared by arc-melting. Based on X-ray phase and structural analysis synthesized alloys depending on its composition contain intermetallics with PuNi₃, Gd₂Co₇ and CaCu₅ structure types. The influence of Y/La and Ni/Co/Mn/Al substitution on the discharge characteristics of the AB₃ and AB₄ electrodes was studied. Substitution Y by La and further Ni by Mn and Al lead to increasing discharge capacity from 40 to 341 mAh/g. Positive effect of Ni/Co/Al or Ni/Mn/Al substitution was also observed for the AB₃ electrodes. The high discharge capacities of 318 mAh/g and 340 mAh/g were seen for the YNi_2.65Co_0.2Al_0.15 and YNi_2.65Mn_0.2Al_0.15 electrodes.

Abstract: Following the rapid growth of the automotive and communication industries, components with high quality and low cost are eagerly desired in China. Various technologies have been developed in China to meet the demand, while semi-solid processing (SSP) of alloys and composites is one of the most successfully developed and practically applied technologies. The major SSP applied in China is the rheocasting in terms of the Swirled Enthalpy Equilibration Device (SEED) process. In this review, we start with a brief reviewing some common slurry preparation methods and recent innovations of the SEED process. Subsequently, we describe the general situation and some recent examples of successful development and applications of SSP in China. Lastly, the future directions in SSP of alloys and composites are highlighted in this frontier research field at the end of this review.

Abstract: This paper presents the results of the application of new unique techniques based on plasma nanotechnology in metallurgy and materials science. In recent years, a team of authors have developed the solutions for extraordinary problems arising in the conditions of metallurgical enterprises related to the production of synthetic materials and control of manufactured products, namely, the methods for the production of various structural materials and optimization of methods for their non-destructive testing by atomic emission spectral analysis (AESA). The paper points out some aspects of ongoing research, in particular, an innovative technique that allows obtaining ultrapure samples of white corundum by plasma melting of alumina in a reactor. This method also allows obtaining ultrapure aluminum at the output, which can be used for the purposes of hydrogen energy. In the course of the research, the criteria for thermal protection, temperature conditions and optimal parameters of the plasmatron were determined. In order to carry out the studies of metals and alloys by AESA method, a new global analytical method was developed, which made it possible to take into account the influence of various important parameters, including third elements, background plasma radiation, etc. This method has been preliminary tested on emission spectrometers made in Russia and can significantly reduce the error in the determination of low concentrations of elements. In addition to the consideration of these parameters, the method makes it possible to perform high-precision calibration of atomic emission spectrometers of the same type (produced in series), using not a set of several tens of approved standard samples, but only two standard samples. For each area, patent applications were formed and filed.

Abstract: Hot corrosion is the main reason of failure of boiler tubes used at high temperature in thermal power plants. This paper is an attempt to investigate the effect of different composite coatings on boiler tube steel in corrosive environment of Na₂SO₄ – 60%V₂O₅ at 900°C for 50 cycles. The coatings have been deposited with high velocity oxy fuel process. The samples were exposed to hot corrosion in a Silicon tube furnace at 900°C for 50 cycles. The kinetics of corrosion behaviour were analysed by the weight gain measurements after each cycle. Corrosion products were analysed with weight change statistics, X-ray diffraction, and scanning electron microscopy. It is found that 100Cr₃C₂ composite coatings provided the higher resistance to corrosion as compared to other types of coatings. Cr carbide layer was formed on the surface and these layers provided the protection from hot corrosion.

Abstract: One of steel 08H14N5M2DL scopes in the industry is an aircraft industry, to be exact, production of racks of the chassis for airplanes and helicopters which test cyclic types of loadings (take-off/landing). Despite the margin of safety which is put at the design of the aircraft, an important role plays, both quality of the material and its ability to save the mechanical properties during all assigned resource for the aircraft. Therefore the development of necessary conditions of production of steel under which the highest mechanical properties and also the ability to save them on the maximum period will be received becomes relevant and today. Work purpose: Identification and prevention of the most significant negative factors having an impact on mechanical properties of steel 08H14N5M2DL in the course of its receiving. In the work, 257 melting of steel of VNL-3 brand in the open IST-0.16 induction furnace with lining from a ground, magnesite brick is investigated. Methods of research are control of the content of austenite and existence of δ - ferrite in structure there were by measurement of values of a magnetic flux density cold and hot tests on the IFSS-1 device and also calculations of the number of products of wear, the solubility of nitrogen in steel VNL-3 and saturation nitrogen. It is revealed that negative impact on mechanical properties of VNL steel – 3 is rendered by nonmetallic inclusions, the maintenance of δ-ferrite and nitrogen. It is established that for stabilization of mechanical properties of steel, aging temperature after tempering in 500 °C allows to support and save steady indicators of mechanical properties. The fact that δ the ferrite exception of solid steel will allow reducing the oxygen content in it not less, than for 0.019% is confirmed owing to what iron crystallizes in γ-phase, passing δ-modification. The presented results confirm prospects of the developed approach in receiving the high-quality steel intended for use in the aviation industry.

Abstract: The article discusses the features of the casting process of non-ferrous metals, the basic properties of various alloys, affecting the appearance of various defects of the resulting casting. The proposals to improve the efficiency of the casting of non-ferrous metals in metal molds and specific recommendations for improving the performance properties of metal depending on the melt being poured are given.