Papers by Keyword: Aluminium

Abstract: Magnesium alloys are used more and more in automotive industry due to specific strength (ratio between tensile strength and density) of 158kNm/kg versus 46kNm/kg in case of structural steel [1]. Another advantage of magnesium alloys is machinability, aspect and automated caste/extrusion. With this last procedure is possible to achieve high rate of productivity for complicate pieces, needed in automotive sector. Technologically, a big issue of magnesium alloy is its reactivity in contact with carbon steel, accentuated by high temperature and pressure from extrusion chambers.

Abstract: Modern engineering components require composites that are robust, lightweight, and inexpensive as integrated particulate for solid strengthening and corrosion resistance alloy. This study envisions a snail shell particulate (SSP) as a potential biofillers on aluminium alloy due to its inherent characteristics. The fabrication of the developed alloy was done through liquid stir casting method with determination to examine the correspondent physical, optoelectrical, electrochemical, and microstructural behaviour for chemical application. Composite infringement varies from 10% - 25% SSP after optimization using design of experiment. The result of electrochemical analysis showed a notable decrease in corrosion rate with increased SSP content from 12.06 mm/yr, of control sample to (75Al-25SSP) which had a corrosion rate of 7.59 mm/yr, resulting in a 40.1% drop-in degradation rate. Notably, microhardness properties increase from 28.1 to 45.5 HRB as a result of solid strengthening characteristics of doped fillers. Opto-electrical assessment demonstrated decreasing resistivity with higher SSP content, indicating improved current flow resistance. The microstructural properties showcased SSP's distinctive dispersion with few micro pores. The intermetallic phases confirmed their integration into the metal matrix by providing an enhancing adhesion and solid crystalline structure.

Abstract: This study investigates the stress corrosion cracking (SCC) behavior of Aluminum in chloride solutions, focusing on varying bending angles (0°, 90°, and 180°), temperatures (25°C, 35°C, and 45°C), and NaCl concentrations (1%, 2%, and 3.5%). Bending tests using a universal testing machine and corrosion tests employing the open circuit potential (OCP) method and anodic polarization Tafel method were conducted. Results revealed that the highest balanced potential (-0.33684 V) occurred at a 0° bend angle in distilled water, while the lowest (-1.02513 V) was at a 180° bend angle in 3.5 wt% NaCl solution. The lowest corrosion rate (0.002403953 mmpy) was observed at a 0° bend angle in distilled water at 25°C, and the highest (2.18789227 mmpy) at a 180° bend angle in 3.5 wt% NaCl solution at 45°C. Surface characterization indicated significant pitting corrosion in NaCl solutions, particularly at a 180° bend angle, while no pitting was seen in distilled water. These findings highlight the substantial impact of bending angle and chloride concentration on the SCC behavior of Aluminum, providing valuable insights for its application in corrosive environments.

Abstract: The need to obtain a uniformly distributed reinforced particulate on AA6063 aluminium alloy for improved mechanical, corrosion and structural properties has necessitated this study. A well synthesised biocompactable particulate of rice hulls/periwinkle shells under varying matrix of 85Al-9.0RHA-6.0PSA, 85Al-7.5RHA-7.5PSA, and 85Al-6.0RHA-9.0PSA was developed and compared with the control for manufacturing application. The microstructural evolution was observed using SEM/EDS quantification. The intermetallic assessment was done using X-ray Diffractometer (XRD). The diameter of indentation was used to measured the microhardness respnses. The corrosion rate and polarization resistance was examined using Liner polarization resistance technique and open circult potential route under simulated 3.65% NaCl. From the results, 85Al-9RHA-6PSA composite sample exhibited slightly lower Cr, lower j_corr, and higher Pr of 0.3562 mm/year, 3.066E-05 A/cm² and 139.33 Ω, respectively against the control sample. An indication of a significant passive characteristics. The 85Al-9RHA-6PSA composite sample also exhibited few dimples, shrinkage cavities and micropores. With composite alloys, good crystalline were observed inform of Al₁₆Co₇Zr₆Al₁₅Co₄ and Al_0.52Co_0.48Al₁₆Co₇Zr_6. The hardness properties improvement from 54.8 to 63.8% provides a significant effect of solid strengthening performance of the hulls/shells as a biocompactability infringement of structural alloy.

Abstract: Aluminium Metal Matrix Composites (AMMCs) play a significant role in diverse industries such as automotive, aerospace, and structural sectors due to their unique characteristics, including low density, high hardness, wear-resistance, and corrosion resistance. Typically, these composite materials employ synthetic reinforcements like SiC and Al2O3, which contribute to higher production costs. However, agricultural waste materials, which are abundantly available worldwide and pose environmental and health risks, have shown potential as suitable reinforcement materials for AMMCs. This study focuses on the development of a novel aluminium metal matrix composite by incorporating Palm Kernel Shell (PKS) particles into AA 7075 in varying percentages (5wt%, 10wt%, 15wt%, 20wt%). Stir casting was employed to produce the composite samples. Mechanical and anticorrosive experiments were conducted to evaluate the resulting materials. The research findings indicate a significant enhancement in the tensile strength and hardness of the composites, along with a reduction in corrosion rates. The most favorable samples exhibited an 8.25% increase in tensile strength, a 23.9% improvement in hardness, and a remarkable 61.6% decrease in corrosion rate.

Abstract: This study aims to investigate the wear behavior of AA7075 alloy with the reinforcement of Silicon carbide (SiC) and Boron carbide (B4C) particles. Process parameters are crucial for component quality improvement, particularly in metal matrix composites (MMCs), a unique class of materials used in a variety of technical applications, such as but not limited to automobiles, marine, and aeronautics.These are frequently utilized in challenging applications due to their significantly better strength to weight ratios, stiffness, and then standard materials. However, it has numerous disadvantages, including high weight ratios, high deformation and stresses, poor fatigue life cycle, early wear and friction, and so on. Up till now, numerous reinforcements have been employed to address these crucial problems. Due to its superior properties, aluminum matrix composites (AMCs) have been used in many different applications. This work attempts to examine the wear behavior of AA7075 alloy reinforced with silicon (SiC) and boron (B4C) particles utilizing the stir casting process AA 7075-(SiC)-(B4C) composites were produced by employing AA 7075 as the matrix material with silicon carbide (SiC) and boron carbide (B4C) particles as reinforcement in various percentages of weight (5%, 10%, and 15%). Parameters of the composites, including wear behavior, coefficient of friction, frictional force, and pin temperature were assessed through graphical representation.

Abstract: A growing number of additive manufacturing (AM) applications use induction heating because of its precision, affordability, safety, and cleanliness. It is widely used in many industrial processes, such as melting, welding, brazing, and preheating. Wire is a considerably more efficient material to use than powder when used as feedstock. Unfortunately, there is still much to learn about the application of induction heating as a heat source in extrusion-based metal additive manufacturing, particularly when wire feedstock is used. This gap was filled by investigating, inhouse developed metal AM system which consists of the combination of induction heating as a heat source and metal wire as a feedstock in additive manufacturing. For this kind of application, induction heating is especially useful since it produces heat inside the workpiece by creating eddy currents. Finite element analysis was initially used to analyze the suitability of extruder material for printing aluminum material. After this investigation, the ability to print aluminum alloy in an extrusion-based metal wire additive manufacturing process with a cast iron extruder has been evaluated through experimentation. Simulation and experimentation results confirm the suitability of cast iron as an extruder material for printing aluminium alloys in a semi-solid state. The tensile test results of wire samples printed through induction heated metal additive manufacturing have been comparable to those of the original wire due to printing the same in a semi-solid state. Though they did not reach the levels attained by wire arc additive manufacturing and casting processes, it was found that the new extrusion-based wire samples showed better elongation and yield strength than the original wire.

Abstract: Health care associated infections or nosocomial infections (NI) is the fourth leading cause of disease and the most common complication affecting hospitalised patients in addition to a minimum of 175,000 deaths every year in industrialised countries. The Center for Disease Control and Prevention (CDC) states that influenza is transmitted from person to person primarily via large virus-laden droplets or through direct or indirect contact with respiratory secretions when touching surfaces contaminated with influenza virus and approximately 80% of the infections are transmitted via touch surfaces. In the year 2020 the Coronavirus (Covid 19) spread has affected the global community and also caused a great concern for the people and health care workers with a global infected population of more than five million. With the ongoing population rise in the cities growing drug resistant bacteria, increasing infection rate in hospitals and communities, ageing world population strongly indicates the need to minimise the spread of infections via touch surfaces. Metals (and products manufactured from them) such as copper and silver are known to exhibit antimicrobial properties. These metals, or composites containing them, can be used as additives and incorporated into other materials such as paints, plastics and powder coatings to imbue these materials with antimicrobial properties. In this paper we present the inherent antimicrobial properties of a copper containing alloy, two alloys of hospital grade steel (304 and 316), extruded aluminium (606013), anodized aluminium (606013) and zinc clad aluminium (3003-7072). Additionally, these materials were coated in epoxy resin powder coating with and without silver based antimicrobial additive. The ability of these metal alloys to reduce the population of inoculated microorganism numbers was assessed via the international standard (ISO) 22196:2011 Measurement of antimicrobial activity on plastics and other non-porous surfaces.

Abstract: The automotive industry faces a significant challenge in meeting the increasing demand for lightweight and eco-friendly vehicles with reduced energy consumption and lower air pollution. This challenge is driven by factors such as consumer preferences, strict government regulations, technological complexities, cost considerations and market acceptance. Aluminium metal matrix composites (AMMCs) are novel materials with high suitability to address this challenge. Currently, AMMCs used in the automotive industry are reinforced with conventional synthetic ceramic particulates and they have shown tremendous improvements over unreinforced alloys. These composites have wear resistance and strengths equivalent to that of cast iron but with about 67% less density. However, synthetic reinforcements are expensive, have limited availability, possess high abrasiveness, cause unwanted reactions, pose recycling difficulties and their production leads to the emission of greenhouse gases. It is now pertinent to consider the use of agricultural waste derivatives as possible substitutes for these conventional reinforcements. In this work, the various agricultural waste derivatives that have been used to reinforce Al matrixes were reviewed and the potentials of the resulting composites as promising candidates for lightweight automotive applications were assessed. It was concluded that agricultural waste derivatives contained hard ceramics particles which improved the mechanical, tribological, thermal and corrosion properties of AMMCs, making agro-waste derivatives reinforced aluminium metal matrix composites promising for the production of novel lightweight automotive components.

Abstract: This paper integrated two severe plastic deformation methods, namely frictional extrusion, and friction stir spot welding to obtain synergetic benefits and create a friction extrusion spot welding (FESW) process. The FESW process was carried out with the use of AA1xxx Al alloy by interchanging the location of the predrilled extrusion hole (between the upper and bottom plates). The microstructure, tensile-shear load, and fracture behaviours of the welds were investigated. The results revealed the presence of no weld discontinuities/flow-aided defects while the FESW process was effective in filling the extrusion holes irrespective of the location of the predrilled holes. An inverse relationship was found to ensue between the tool’s rotating speed and the tensile-shear load of the bottom plate hole-friction extrusion spot welded joint joints while a direct correlation occurred between the tensile-shear load and the rotational speed (up to 1100 rpm) in the top plate hole-friction extrusion spot welded joints. The difference in the tensile and fracture behaviours of the two weld categories is attributed to the disparity in the hole-filling mechanisms. The maximum tensile shear load of 3.1 kN (at 710 rpm) and 3.3 kN (at 1100 rpm) were obtained in the bottom plate hole-and top plate hole-FESW joints respectively.