Papers by Keyword: Magnesium

Abstract: Magnesium aluminium of the magnesium-alloy variety have long been extensively utilized in different technical applications and are still capturing the attention of researchers because of their cost-effectiveness and lightness. Grain fractal sizes, microstructural relationships, and sphericity, as well as their relationship with service performance, were discovered for numerous frequently employed Mg-Al alloys. As a result, the influence of cow’s bone extracts calcium on the mechanical behaviours as well as microstructure of Magnesium aluminium alloy was investigated in this work. Calcium (0.5% weight) concentration, formations with uniform and non-uniform grain boundaries led to alloy hardening. 286.537MPa and 57.3 HB are respectively the highest tensile strength and hardness gotten.

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: Magnesium and its alloys display a non-usual relationship between flow stress and grain size at room temperature. Breaks in the Hall-Petch relationship have been reported in the literature. Inverse Hall-Petch behavior in which flow stress reduces with grain size decreasing has also been reported in pure magnesium and magnesium alloys with ultrafine and nanocrystalline structures. The present overview discusses these effects in terms of controlling deformation mechanisms. The distinct strength observed in pure magnesium and magnesium alloys with ultrafine grained structure is also discussed. It is shown that experimental data for fine and ultrafine grained magnesium alloys agree with a model suggested recently based on the mechanism of grain boundary sliding. It is also exhibited that the stability of the grain structure might control the strength of ultrafine grained samples.

Abstract: In this study, AZ91 alloy was used as the base material and calcium and cerium were added as alloying elements. Microstructural analysis through optical microscope (OM) and field emission scanning electron microscope (FESEM) revealed that AZ91 base alloy contains α-Mg matrix and β-Mg₁₇Al₁₂ interdendritic network. The inclusion of individual calcium and cerium resulted in a more homogeneous distribution of the interdendritic network in the AZ91-1wt.% Ca and AZ91-1wt.% Ce alloy. The secondary phase (Mg₁₇Al₁₂) was refined in the microstructure as a result of Ca and Ce addition where Ce addition forms a new rod-like phase that is recognized as Al₁₁Ce₃ and Ca addition forms a skeleton like structure of Mg₁₇Al₁₂ and Al₂Ca. Due to the formation of new Al₂Ca and Al₁₁Ce₃ intermetallics, the volume fraction of β-Mg₁₇Al₁₂ was more suppressed with Ca and Ce alloy additions. The grain size determined from Electron Backscatter Diffraction (EBSD) maps indicate the reduction in average grain size with individual Ca and Ce additions. The addition of these elements was found to improve the hardness of AZ91 alloy. Overall, the results of this study demonstrate the potential for using Calcium and Cerium as alloying elements in AZ91 alloy to improve its mechanical properties by modifying its microstructure.

Abstract: Industrial waste is primarily handled using landfills in both developed and developing countries. While there has been a significant rise in solid waste reduction, reuse, and recycling, landfill disposal will inevitably remain the most commonly used form of waste management. Although landfilling provides an economic means of waste disposal, it can lead to environmental degradation by releasing various contaminants if not managed properly. In this work, industrial waste from electrostatic precipitators (ESP) will be beneficial for the production of coatings on metal substrates. The sol-gel coating method have been attempted for deposition on pure Mg samples. Using the potentiodynamic polarization (PDP) method and hydrogen evolution analysis, the effectiveness of the coating, which is the corrosion resistance was analyzed. A minimal application of Tetraethyl orthosilicate (TEOS) in the ESP dust solution has been shown to substantially reduce the corrosion rate of Mg. This is likely due to the impact of its concentrations through the sol-gel process that could increase the size of the particle shape or growth.

Abstract: Developing Mg based implants for temporary applications based on their biodegradation in the physiological environment is a potential research area in the biomedical engineering. Assessing the bio-corrosion in simulated conditions helps to reduce the complexity of research studies associated with in-vivo experiments and can be used to assess the true behavior of the Mg implant in artificial solutions. On the other hand, assessing the corrosion behavior by using 3.5% NaCl solution is a standard ASTM protocol widely used in the industries. Hence, in the present work, degradation of pure Mg due to bio-corrosion in two different solutions i.e simulated body fluids (SBF) and 3.5% NaCl solution has been investigated. From the results, the weight loss measurements indicated higher degradation during the initial 24 h in SBF solution. However, with the increased immersion time to 72 h, due to the deposition of mineral phases from SBF as confirmed from the electron microscopy and X-Ray diffraction study, the degradation was observed as decreased in SBF compared with NaCl solution. Hence, the results demonstrate that the evaluation of degradation behavior of Mg based materials in simulated physiological environments is appropriate compared with the standard NaCl environment.

Abstract: The present paper deals with the study of magnesium alloy hybrid composites. AZ91 is a popular magnesium alloy with good specific strength at room temperatures. However, it suffers with poor mechanical properties at elevated temperatures. The reinforcement materials can be prepared by polymers and ceramic particles. The selection of proper material will have a greater response on the properties. Therefore, in order to increase the mechanical responses, preparation of composites is good idea with low cost. To ensure multiple properties, it is always necessary to go with Hybrid composites. In this context, this paper reviews the materials used in the fabrication of composites, fabrication Techniques, microscopic behaviours and mechanical responses. This paper also provides research potentials along with the latest developments in the area of AZ91 Composites.

Abstract: Biodegradability of magnesium alloys in physiological media is important for material use in implant manufacture industry. Two industrial Mg alloys ZQ71 and ZQ63 were investigated. Optical microscopy was used to put in evidence microstructure. The conclusions are correlated with obtained results after scanning electron microscopy investigations coupled with energy dispersive X-ray spectroscopy. The evaluation of the hydrogen released rate was analyzed in laboratory made simulated body fluid (SBF) and Hanks’ solution at 37°C for 10 days. Different degradation rates are obtained, and it can be concluded that they depend on chemical composition of the alloys and on immersion time of the samples in different physiological solutions.

Abstract: A growing demand for advanced composite materials as well as diverse design requirements offering significant weight savings in comparison to conventional materials have all contributed to a growing interest in composite materials. This review paper is focused on Powder Metallurgy (P/M) process to fabricate magnesium based metal matrix composites. The excellent oxidation and corrosion resistance and low density of Silicon carbide have made it a popular material even at very high temperatures. Despite their very high specific strength, magnesium matrix composites possess excellent cast ability, good damping capabilities, and greater machinability. Therefore, this review paper discusses the importance, fabrication, and properties of magnesium matrix composite materials for industry applications. An examination of the properties of recently produced magnesium matrix composites by various researchers is presented in this review paper.

Abstract: The magnesium is selected for the future implants material due to its excellent biocompatibility behavior. The biodegradable and biocompatible nature of Mg and its alloy make it prime choice for the development of bio-implants. The mechanical properties of Mg are similar to natural human bone therefore it can be used for temporary implantation for supporting a fracture bone. The rapid biodegradation of pure Mg before the healing time, raise the requirement to develop a metal matrix composites of Mg. The prominent technique of MMC fabrication is friction stir processing (FSP). The FSP is widely used for fabrication of surface composites and also used for grain structure refining and strengthening. The current article reviewed the various surface composites of Mg developed by FSP for alteration of biodegradation and mechanical properties. .