Advances in Science and Technology Vol. 120

Abstract: This work emphasize on utilization of fly ash in to novel aluminium alloy (Al-2024). The Al-2024 alloy and composites (≈10%flyash) prepared by stir casting technique. The composites is cold forged and identified properties (mechanical, structural and stress distribution in component). Upset tests at room temperature, during the deformation process, provide representative behaviour. The metallographic structure of alloy revelled dendritic and composites shows fine spherical prime segment split and regularly dispersed intermetallic compounds. The stress intensity and distribution of temperature were examined in depth at different input combinations. Compression tests were conducted on Ø 12 mm cylindrical specimens at an H/D ratio of 1.0 and 1.5 for alloy and fly ash composites (2, 6 and 10 wt %). In determining the forging load, the upset ratio defined as the mainly important factor. The strain in composites increased with increasing % of reduction in size and decreased with % of fly ash.

Abstract: Graphene is a wonder material, and it has remarkable mechanical property not only limited to few kind of mechanical properties. This included electrical, optical, thermal capability and resistivity. It is hypothetically an excellent method to approach with Reinforcement in metal matrix composites. This paper totally depends on review of Aluminum – super extended graphite material, super extended graphite is commonly known as a ‘Graphene’. This paper focuses on the review about fabrication methodology and problems faced in fabrication of Al-Graphene based composite, and we analyzed flexible and high possible path to economic consideration. This article covers a step-by-step process for enhancing a composite material for a commercial application. In this study analysis, the mechanical behavior of aluminum-graphene composite is made by potentially reinforced metal matrix method with particulate stir casting method. The main objective of this study is to provide the functional process of graphene based composite effectively. The aluminum (Al-7075 Alloy) is a metal matrix and has 1% of graphene. In recent decades, a hype of graphene material and carbon nano tubes have come due to technological advancement as it leads to commercial establishment. Composite material played the important role in the recent years to replace the traditional material in the easiest manner. Graphene based composite has wide variety of uses and enormous applications to drive for a better future.

Abstract: The usage of reinforcing fibers extracted from nature is increasing in the present decade due to increasing the demand for biodegradability and environmentally friendly materials. In this paper, biodegradable sisal fiber and corn starch powder mixed thermoset and thermoplastic composite are prepared and tested for Young’s modulus. The effect of sisal fiber weight fraction on the Young’s modulus is identified at constant content of corn starch powder. Later, using Micromechanics approach and Finite Element Method simulation studies are performed to estimate transverse Modulus, Shear modulus, major and minor Poisson’s ratio of the sisal and starch based polymer composites. It is found that the composites prepared with sisal fiber and corn starch powder are a promising replacement for plastic reinforced composite to promote the biodegradability, especially under high weight fraction of sisal fiber

Abstract: Titanium and its alloys are potential candidates widely used to manufacture medical implants. In spite of possessing excellent properties suitable for a biomaterial, Ti suffers from lack of ability to bond with the local tissue termed as “bioactivity”. Several strategies have been adopted to increase the bioactivity of titanium for bone implant applications. Micro arc oxidation (MAO) is one of such promising surface treatments which produces an oxide layer on the surface of Ti which promote better tissue interactions at the surface Ti. Hence, in the present work, commercial pure Ti (CP-Ti) has been treated with MAO process and the produced surface was characterized to study the oxide layer developed on the Ti surface. X-Ray diffraction studies demonstrated the formation of TiO₂ layer on the surface of CP-Ti. Scanning electron microscope images and EDS analysis confirms the porosity in the produced oxide layer which is favorable towards better cell interactions. The presence of considerable amount of phosphorous in the oxide layer which is form the electrolyte used during MAO process was also observed. The preliminary findings demonstrate the simple and effective way to produce porous oxide layer on Ti for biomedical applications.

Abstract: Upgrading of reinforcements with suitable combinations in Aluminum-based hybrid metal matrix composites became a key area of research in the current manufacturing era. These advanced materials have enriched Properties like specific strength, wear resistance, and low thermal expansion. With these perceptions, the current research paper was focused on AA-2024/MoS2/Al2O3 HMMCs. Taguchi L18 orthogonal array was adopted to design the experiments. Hybrid composites containing MoS2 and Al2O3 reinforcements were fabricated by the stir casting method. The pin on disk tribometer was used for finding the wear rate and coefficient of friction of prepared composites by considering sliding speed, applied load, and sliding time as wear parameters. Further, the influence of wear parameters on Wear Rate and Coefficient of Friction (COF) was presented. Consequently, the significance of the parameters on wear rate and COF are analyzed by analysis of variance (ANOVA).

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: Research on developing degradable implants from metals is one of the potential research fields in the biomedical engineering. Magnesium (Mg), iron (Fe) and zinc (Zn) are the three metallic systems widely investigated as potential materials to manufacture degradable orthopedic and stent applications. Among them, magnesium-based implants have shown promising properties suitable for orthopedic and stent applications. In spite of several benefits such as biocompatibility, non-toxicity and degradability, magnesium is associated with a few limitations including rapid corrosion and evolution of hydrogen during the degradation in the biological environment. Several materials engineering strategies have been employed to address the limitation of magnesium. Developing composites by incorporating suitable reinforcements into Mg is such promising route to develop Mg based implants with tailored properties. The present review provides a snap shot of the developments reported in development of Mg based composite for degradable implant applications. Different phases used to incorporate into Mg and the influenced properties with the future scope and the challenges are presented.

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: Present usage of Metal Matrix Composites is high in engineering applications. Especially, Al 6065 aluminum alloy is finding suitable for many applications of engineering components. In this work, a metal matrix composite has prepared with the pure Al 6065 aluminum alloy as matrix and Calcium silicate (CaSiO₃) as reinforcement using bottom pour stir casting machine. The percentage of Calcium silicate (CaSiO₃) has been increased from 1 % to 4 % in steps of 1% by weight. The reinforcement has been distributed over the matrix for which micro structural analysis and hardness test has been performed. The hardness values are found to be increasing with increase of reinforcement.