Papers by Keyword: Aluminium

Abstract: Particulates of cow bone (CB) and coconut shell (CS) were infused within the microstructure of 1170 aluminium alloy and studied for their influence on the corrosion resistance of the resulting aluminium matrix composites in 3.5% NaCl, 0.05 M H₂SO₄ and 3.5% NaCl/0.05 M H₂SO₄ solution by weight loss method. Corrosion rate data shows CB and CS significantly influenced the electrochemical properties of the composite. Protection performance data at 336 h of exposure shows CB and CS particulate significantly reduced the corrosion resistance of the aluminium alloy at all weight compositions in 3.5% NaCl solution. In 0.05% H₂SO₄ solution, CB improved the corrosion resistance of the composite at 5% - 15% weight composition (37.8%, 23.22% and 23.22%), while CS improved the corrosion resistance at 10% and 20% weight composition (37.65% and 28.52%). The corresponding values for CB in 3.5% NaCl/0.05 M H₂SO₄ solution occurred at 5% - 15% weight composition (34.26, 31.71% and 22.68%) while for CS it occurred at 10 and 15% weight composition (40.52% and 46.05%). Data from ANOVA statistical tool shows particulate weight composition and exposure time are both relevant determinant variables (greater than the theoretical significance factor) influencing the protection performance outputs of CB and CS with values ranging between 41.82% to 92.5% for weight composition and 5.68% and 53.03% for exposure time. Standard deviation data for CB particulate varied minimally only at 20% weight composition in 3.5% NaCl solution. The corresponding data at other CB weight compositions and for coconut shell at all weight compositions varied significantly due to thermodynamic instability.In 0.05 M H₂SO₄ and 3.5% NaCl/0.05 M H₂SO₄ solutions, all standard deviation values for CB and CS particulates (excluding CB at 29% weight composition) at all weight compositions vary minimally from the mean data signifying thermodynamic stability of the electrochemical reactions on the composite surfaces with respect to exposure time. The proportion of data above 20% protection performance for CB and CS particulates in 3.5% NaCl solution is 0% at margins of error of 0%. The corresponding values in 0.05 M H₂SO₄ solution are 15.18% and 15.32% at margins of error of 40% and 43% while the values from 3.5% NaCl/0.05 M H₂SO₄ solution are 14.78% and 15.5% at margins of error of 35% and 50%.

Abstract: The cold spraying process is numerically modeled using Lagrangian and Arbitrary Lagrangian Eulerian (ALE) techniques. The simulations were performed to predict the critical velocity of spherical aluminum particles deposited on the aluminum substrate. ALE technique was found to be more suitable than the Lagrangian technique. Using Lagrangian and ALE techniques, the critical velocity for aluminum was predicted as 605 m/s and 770 m/s. Critical velocity was in between 770-775 m/s, as reported in the literature. The Lagrangian technique's capability is limited in capturing large deformations associated with cold spraying. However, this technique requires less computational ability and is quicker than the ALE technique. The jet formation was prominent in the case of the Lagrangian technique, and hence the difference between the numerically estimated value of critical velocity and experimentally measured velocity is more. The Compression ratio was found to increase with an increase in impingement velocity.

Abstract: Surface marks, such as scratches or cosmetic marks, commonly appear during the manufacturing phase of metallic components, because of the contact between tools and sharp edges with the surface of the parts. Scratches, depending on their width, depth, and root radius, cause a decrease in the fatigue life of metallic alloys. In particular, the presence of scratches with a size comparable to the grain size favors the generation of fatigue cracks in these features. In the aerospace industry, the presence of surface marks is a common cause of rejection. The low hardness of aluminium, a material widely employed in the manufacture of aerospace structures, contributes to the generation of surface marks. In this paper, a preliminary geometrical characterisation of scratches is established. It aims to define a set of parameters to characterise exhaustively the different scratches and to generate different behavior models for each type of scratch. Parameters such as scratch length, path radius, and burr height are considered in addition to the well-known parameters such as scratch depth, root radius, and open angle.

Abstract: Lightweight, robust, and anti-rust properties of aluminium foam might be a solution for reducing the effect of traffic accidents and for minimum fuel consumption. This research investigated the crashworthiness of vehicle crash-box filled with aluminum foam by varying its cross-sectional structure and its loading angle such as 0°, 10°, 20°, 30°. The variations consisted of structures for example single wall foam filled and double wall foam filled. The material used to construct the wall was Aluminum Alloy 2024 and Aluminium foam. The finite element model using Abaqus CAE Software was operated for both designing the crash-box and analyzing its crashworthiness. Some parameters were determined To obtain the best crash-box design, the finite element analysis was carried on total energy absorption, specific energy absorption, maximum load, average load, and crush-force efficiency. Double wall foam filled crash-box was shown to have better energy absorption ability and this structure of crush box is considered fpr vehicle structure in future.

Abstract: In the present work, the effect of cryo-rolling on the processed LM6 alloy samples has been studied. The solution treated (ST) sample of LM6 alloy has been processed through cryo-rolling with reduction of its thickness with values such as 30%, 40%, and 75%. One of the key material properties i.e., fracture toughness has been studied and equivalent energy fracture toughness ( ) is being evaluated according to the ASTM E 992 standard. The microstructure evolution after processing through cryorolling (CR) has been carried out with the help of optical microscopy and Scanning Electron Microscopy (SEM). Then, the calculated values of fracture toughness parameter i.e., equivalent energy fracture toughness ( is being correlated with the microstructure evolution after processing of LM6 alloy. It was found out that there is an improvement in equivalent energy fracture toughness ( ) as the reduction values increases. The 75% CR sample showed great increment of 67% as compared to ST alloy sample. The microstructure evolution also signifies the mix-mode fracture visualized through Scanning Electron Microscopy (SEM) and as the reduction values increase, the ductile fracture zone dominance increases on brittle fracture zone indicating there is improvement in fracture toughness of the ultra-fined grain LM6 alloy due to the grain refinement, dislocation strengthening and grain boundary strengthening.

Abstract: Aluminium matrix composite is a type of innovative technical material that have applications in aerospace, automotive, biotechnology, electronics, and a lot more. Non-metallic reinforcements can be injected into an aluminium alloy to provide advantages over base metal (Al) alloys. Better mechanical properties, improved microstructure, and corrosion resistance are the benefits that have been noticed upon reinforcements. The proportion of reinforcement, kind, size, and forms of aluminium matrix are all important factors in improving mechanical and tribological properties. Investigation in the creation of highly advanced tailored materials using liquid and solid-state processes and the impact it has on the properties and application are the subject of this work. The current research summarizes recent breakthroughs in aluminium-based composites and other particle reinforcement effects. The experiment findings revealed that strengthening the aluminum matrix with reinforcements increased mechanical properties and improves the microstructure. Also, stir casting was seen to be the most popular liquid metal approach because of its cost effectiveness and processing parameters which could easily be adjusted and monitored. It is concluded that aluminum matrix composites have greater mechanical characteristics, microstructure, and corrosion resistance than unreinforced aluminum alloys.

Abstract: Nowadays, there is an ever-increasing demand for lightweight, robust, and low-cost materials. The desire for increasingly exotic and superior materials has become unavoidable as science progresses. The manufacturing industry is looking for more complex geometries. For example, composite materials are a sort of innovative material that blends the properties of its constituent materials. One of the most extensively used composite materials is metal matrix composites. Aluminium matrix composites are lightweight, high-performance structural and functional materials used in a variety of industries, including defense, aerospace, automotive, heating systems, and sports and entertainment. It is really good for the environment to use by-products from agricultural sectors, such as rice husk, as reinforcement with MMCs. The purpose of this research is to use powder metallurgy technology to build an aluminum-based composite with rice husk ash (RHA) and evaluate how its properties may be enhanced. Whereas metal casting can be used to fabricate composites, powder metallurgy is more cost-effective because it allows for the production of parts that are closer to net shape, and castings cool slowly from the liquid state, causing workability concerns as well as other restrictions such as segregation limitations. Good microstructure in the finished product is possible to obtain as powder particles are small and homogenous, resulting in improved mechanical properties. The experiment was conducted using an L27 orthogonal array with four different input parameters from prior studies: composition (wt.% of RHA), compaction pressure (CP), sintering temperatures (STE), and sintering time (ST). On the aluminium based composite, several mechanical tests, such as density and hardness, as well as tribological testing, such as the wear test, were conducted, with each test yielding noteworthy results. To satisfy the industry's needs, a comparison study was conducted.

Abstract: Metal matrix composite materials are a novel material generation capable of handling the implementation of advanced technology's growing needs. Aluminium-based metal matrix composites are widely used in automobiles and aerospace, as well as other industries, including defence and marine systems, due to their relatively low processing costs as compared to other matrices such as magnesium, copper, titanium, and zinc. Ceramic particles were shown to improve mechanical properties like hardness and tensile strength. The product's compactness and price, however, were both boosted. Agricultural waste materials are widely available today in significant amounts, and researchers have focused on using wastes as reinforcing fillers in composites to counteract pollution. Rice husk ash added to an aluminium alloy matrix increases the composite's mechanical properties while also increasing its wear resistance. According to scanning electron micrographs of the composite, the ash from rice husks is evenly distributed all over the aluminium matrix. Wear can vary from micro-cutting to oxidation at high temperatures in an aluminium alloy. Strain fields are produced and composite material wear resistance is improved due to the difference in coefficients of thermal expansion between the matrix and reinforcing materials. This study focuses on the production process, properties, and performance of an aluminium alloy composite incorporating rice husk ash, which has high hardness as well as wear resistance.

Abstract: As additive techniques such as laser powder bed fusion find increasing adoption industry, the ability to adapt these processes to industrially relevant materials is paramount. This adaptation can represent a significant challenge when working with wrought alloy feedstocks, which often result in brittle or porous parts lacking the mechanical properties of their conventionally wrought counterparts. One such alloy, aluminium 6061, is a highly used alloy in the aerospace, automotive, and semiconductor manufacturing industries. The conventionally manufactured components can have complex morphologies and may be assemblies of multiple individual components. As such, the ability to use an additive approach, and produce these as single parts can lead to significant benefits.In this work, we examine laser powder bed fusion of aluminium alloy 6061. The effects of process parameters such as laser power, beam scan speed, hatching distance, spot size was examined with a view towards developing an optimised process for this traditionally wrought alloy. Parts were examined for porosity and microstructure, with an aim to develop greater than 95% relative densities. To aid in process optimisation, in-situ pyrometry was deployed to understand the effects of the process parameters and develop a robust and repeatable process for producing 6061 components.

Abstract: In the simulation of bulk forming processes the validation of the applied simulation models is necessary. Then, predictive simulations are possible. A visualisation method is an advanced way to create additional evaluation parameters. In this work, the upscaling of a newly developed non-destructive method from semi-industrial to near-industrial scale for metal extrusion of aluminium alloys is presented. A copper coating, which deforms with the billet material, was applied to one half (in the longitudinal direction) of a cast billet and detected by computed tomography (CT). The copper pattern was applied by a plasma coating technology to determine the deformation of the billet material during the process until the final profile. A detailed analysis of the upscaled method with improved geometric setup shows the superiority of the newly chosen properties enabling a complete determination of strain state also in the profile.