Grade Aluminum Research Articles

Mathematical modelling to predict angular distortion in MIG welding of aluminium 6063 plates

Goal of the present investigation is to see how different operational factors such as voltage, weld speed, nozzle plate distance (NPD), torch angle, and wire feed rate affect the angular distortion of welds on aluminium 6063 plates. This grade of aluminium has extensive applications ranging from industrial to domestic usage. A structured set of experiments were carried out using the statistical approach of design of experiments. The CCRD (central composite rotatable design) approach developed a mathematical model relating the response, angular distortion and input parameters. The adequacy of this model was checked by using the ANOVA technique. For studying the results graphically, RSM (Response Surface Methodology) is applied. The developed model optimises the input parameters to minimise the resultant angular distortion. Such a prediction of angular distortion before welding could be of significant help in improving and maintaining weld joint quality.

The Significance of Size Screening on the Pretreatment of Low Grade Bauxite: A Case Study of Block E70 / 3160 in Darling Range of Australia

In this paper, the size screening method and X-ray fluorescent spectroscopy were used to analyze low-grade bauxite samples from Darling Range, Australia. The results showed that the Av Al / Re Si(available alumina to reactive silica ratio) of samples JDB225 and JDB364 increased by 34.5% (8.7% to 11.7%) and 11.2% (8.9% to 9.9%); the available aluminum increased by 11.2% (27.8% to 30.9%) and 4.9% (30.9% to 32.4%) respectively. In screening, the optimum particle sizes of the two samples were 4 mm and 2.8 mm respectively. The results show that the best screening particle size can be determined by the size screening method, which can achieve the optimal combination of available aluminum grade, Av Al / Re Si and mass recovery rate, so as to significantly improve the grade and Av Al / Re Si of low-grade bauxite.

Influence of aluminum ion on the structural, optical, and electrical properties of CuO thin films for the PN-Junction diode application

Pure and (1, 3, and 5 wt%) Aluminum-doped copper oxide(Al:CuO) thin films were prepared using the JNS spray-pyrolysis technique using analytical grade copper chloride and aluminum chloride as a precursor. The monoclinic structure of the CuO film has been confirmed by an X-ray diffraction (XRD) study. The microstructure of the films is analyzed with the help of a scanning electron microscope (SEM). The optical characteristics of the grown films have been examined with the help of UV–vis spectroscopy, from which the bandgap of the materials of the coated films are calculated. Electrical properties such as conductivity and the diode activity of the films are studied using I-V characterization, which shows the improved electrical conductivity with the increase in doping concentration. Diodes are fabricated using pure and Aluminum-doped p-type CuO thin films coated on the n-type silica wafer by the JNS technique, and the rectification behavior is found to improved at a higher doping concentration of Al3+ ions.

Metallographic analysis of in-house developed marine grade aluminum alloy AA5086friction stir welds

A friction stir welding (FSW) setup was developed and performed trial experiment on marine grade aluminum alloy 5086 in the present work. The input parameters were traverse speed (56 and 80 mm/min) and spindle speed (750 and 1000 rpm). From study it was observed that the spindle speed has an immense influenced on joint formation compared to feed speed. The rotational speed of 750 rpm produced defect joints due to inadequate welding heat generation and joints without defect were achieved at 1000 rpm spindle speed. The metallographic analysis and mechanical testing were conducted for the defect-free weld joints.

Mathematical Modelling to predict dilution in MIG welded aluminium 8011 plates

During MIG (Metal Inert Gas) welding, mixing of the base metal with the filler metal deposited onto the weld causes a change in the composition of the weld metal called as dilution which generally is undesirable. The degree of dilution depends on the type of joint and joint edge preparation, the welding process, process parameters, and the technique used. The purpose of this study is to look at the effects of different input parameters on dilution in MIG welding. 5 mm thick 8011 grade aluminum plates were used for this experiment and using the statistical technique of design of experiments, a mathematical model to relate dilution to various input factors is built. The dilution is calculated by taking the ratio of penetration area to the total area of the weld bead. To create the design matrix for the trials, the central composite rotatable design (CCRD) is employed. With the help of Response Surface Methodology (RSM), the findings are graphically examined. The developed model is employed to optimize the input parameters in order to achieve the lowest possible dilution.

Study of wear properties of Al7075-SiC-Gr composites using Taguchi and ANOVA methods

This research work aims to study the wear properties of Al7075 grade aluminium based MMCs reinforced with SiC and Gr particles. Powder metallurgy process was followed to fabricate the composites with Al7075 particle sizes of 24 μm and 50 μm, SiC with varying weight amounts of 6, 12 and 18% and graphite (Gr) with constant weight of 4%. The composite samples were tested for wear loss and coefficient of friction using pin-on-disc wear test apparatus under dry conditions with varying sliding speed, distance and applied load. The experiments were designed using Taguchi L18 orthogonal array. The findings from S/N ratio and ANOVA approaches revealed that the most significant parameters influencing the wear loss were SiC content and applied load, while for the friction coefficient were applied load and sliding distance. Composite properties were improved by the amalgamation of smaller matrix particles (24 μm) and a higher reinforcement content (18 wt%).

Finite element simulation of liquid nitrogen temperature rolling of marine grade aluminium alloy 5754

Now days, numerical approaches are becoming an efficient practical tool for the analysis of elastoplastic behavior of various engineering materials. Present study elaborates about the numerical investigation of liquid nitrogen temperature (LNT) plate rolling operation of marine grade aluminium alloy 5754 (AA 5754) by finite element method. To serve this purpose, commercially available ANSYS software package has been utilized to perform LNT-rolling simulation. In literature, it is well documented that LNT-rolling immensely increases mechanical strength through grain refinement technique. During rolling at liquid nitrogen temperature, the dynamic recovery process is inhibited which leads in accumulation of high rate of dislocation defects. Consequently, with due rolling these accumulated dislocations attributed towards formation of ultrafine grain (UFG) structure. The aim of this work is to formulate an efficient method to numerically investigate the deformation characteristics of AA 5754 during LNT-rolling. Geometrical and experimental parameters like roller diameters, dimensions of flat plate, roller speed, friction coefficient etc. are incorporated in the preprocessor module of ANSYS software. An optimized meshed domain is selected for simulation of 40% thickness reduction of AA 5754. The temperature effect and corresponding stress distribution in the flat plate of AA 5754 is well captured and comparative analysis with the experimental practices has been successfully carried out. Numerical results obtained in the form of uniform thickness reduction, elastoplastic stress and strain contour plots, pressure force exerted by roller etc. are in good agreement with the experimental rolling operation.

The effect of lithium fluoride compound on slag decomposition in the process of casting aluminum prepared details

The article analyzes the dependence of a lithium-fluorine-containing compound on the release of slag in the manufacture of cast parts from aluminum alloys. Experimental samples were obtained by firing in a resistance furnace at 750° C. In the experiments, a different amount of fluorine-lithium compound was used as a flux. Aluminum grades AK7 and D16 were used in the research. The article also presents the authors’ conclusions about the effect of the fluorine-lithium compound on the release of slag based on the experiments conducted.

Locating Cracks in 1050 Aluminium Alloy by Digital Image Correlation

In this paper deformation of commercial 1050 grade aluminum alloy is studied by digital image correlation (DIC) technique using open-source software, Ncorr. For this purpose, samples of aluminum alloy were subjected to uniaxial deformation under a scanning electron microscope (SEM) till the initiation of crack. Intermittently images were captured during deformation and by using DIC technique, variations in the microstructure of the deformed samples were identified in terms of displacement. Using these displacements, normal strains Exx, Eyy, and Exy shear strain were estimated to subpixel accuracy. By superimposing the region of crack and distribution of strains in the microstructures, it was possible to show that near the crack, strains not only attain high values but also show large fluctuations. Various aspects relating to the nature of strain distribution are discussed in the paper.

Study on the weldability of AA2519 armor grade aluminium alloy

This paper describes series of studies concerned with welding of Sc-modified AA2519 at the Military University of Technology. The modification of AA2519 alloy contains a higher concentration of scandium and zirconium and it has been developed in The Institute of Non Ferrous Metals, Light Metals Division in Skawina. The examination involves friction stir welding (FSW) and laser beam welding (LBW) of 5 mm thick AA2519-T62 extrusion. FSW process parameters were: 600 rpm tool rotation speed, 100 mm/min welding velocity, 4.8 mm depth plunge, and MX Triflute tool type. The used LBW parameters were as follows: 3.2 kW laser power, 1.1 m/min welding velocity, 0.2 mm laser beam width, 10° laser beam inclination angle, 10 L/min shielding gas (argon) flow with the laser beam focused on the workpiece surface (f=0). In this work selected results have been presented containing some problems and features typical for investigated joints. Butt joints produced by FSW and LBW have been compared in terms of microstructure (grains), microhardness distribution, joint efficiency, localization of failure, etc. The basic features of weld zones have been discussed together with the distributions of microhardness on the joint’s cross-sections. Both welding techniques cause a reduction of microhardness in the weld zone, but the drop from the base material’s value (135-140 HV0.1) is far higher in the case of LBW (85-90 HV0.1) than FSW (120 HV0.1). The established values of joint efficiency were 80% (376 MPa) and 66% (314 MPa) for FSW and LBW, respectively. The FSW joints tend to fail in the thermo-mechanically affected zone and LBW in the fusion zone.

Constitutive relations for materials with strain state dependent properties

Many materials demonstrate a dependence of mechanical properties on the type of stressed or deformed states. This is most noticeable in the dependence of the processes of shear and bulk deformation. Such materials include rocks, structural graphite, concrete, some grades of steel, cast iron, and aluminum. The main properties of these materials are an absence of a "single curve" relationship between the intensity of stresses and the intensity of deformations. Under shear conditions, bulk deformations can occur. Such materials can be described by constitutive equations that depend on the parameter of the type of a stress state, which is the ratio of the first invariant of the stress tensor to the stress intensity. Thus, these defining relations give the dependence of the strain tensor components on the stress tensor components. Such defining relations can be quite cumbersome, and therefore do not allow an analytical treatment to obtain defining relations that give the dependence of the components of the stress tensor on the components of the strain tensor. The paper proposes the constitutive relations obtained from the analysis of test results of various materials, which properties depend on the type of deformed state. Conditions are derived for material constants that ensure the uniqueness of the solution of boundary value problems. Based on experimental data obtained under the conditions of the proportional loading of various rocks: limestone and talcochlorite, as well as the results of mechanical tests of several grades of concrete, the constants of the mathematical model are determined. The results of the experimental studies are compared with theoretical dependencies predicted by the model. The limited applicability of the proposed constitutive relations is established.

TRIBOLOGICAL CHARACTERISTICS OF ANTIFRICTION COMPOSITES OF POLYAMIDE AND ULTRA-HIGH MOLECULAR WEIGHT POLYETHYLENE

Analysis of current trends in improving the designs of tribo-couplings of agricultural machinery has shown that the use of polyamide 6 as an antifriction material is limited by its low moisture resistance, which leads to a significant deterioration in its elastic-strength and tribological characteristics during moisture saturation. The paper shows the possibility of using ultra-high molecular weight polyethylene as its analogue, which allows increasing the durability of tribo- couplings of hydraulic systems of agricultural machinery. (Research purpose) The research purpose is in to study the processes of friction and wear of polyamide PA 6 composites and ultra-high molecular weight polyethylene nanocomposites with obtaining dependencies linking tribological characteristics (friction coefficient and wear intensity) with operational factors (temperature, sliding speed and contact pressure). (Materials and methods). Polyamide PA 6 of the 210/310 brand was used in the work; composite of the UPA 6-15A brand, consisting of 85 percent polyamide PA 6 and 15 percent fibrous carbon filler; ultrahigh molecular weight polyethylene of the GUR 4120 brand; Tuballmatrixbeta concentrate of activated carbon nanotubes; hydrophobic nanocrystalline silicon dioxide with a dispersion of 20 nanometers, Nafen grade aluminum oxide nanofiber with a dispersion of 10- 20 nanometers. Samples were made to study the elastic-strength and tribological characteristics of composites by thermal pressing on a Gibitre hydraulic press. Samples were tested on the UAI-7000 M bursting machine and the Haake MARS III rheometer. (Results and discussion) The values of the intensity of linear wear and the dependence of the friction coefficients of composites on the sliding speed, contact pressure and temperature of industrial oil I-20A were determined for the conditions of dry friction and friction with lubrication. (Conclusions) The research results have shown that the use of ultrahigh molecular weight polyethylene and nanocomposites based on it as commercial antifriction materials of tribo- couplings is promising and requires further study.

Tool wear in the single point incremental forming

The single point incremental forming (SPIF) is an immerging forming technique in which the metal sheets are shaped to a simple tool rather than the dedicated dies. The SPIF is more suitable for the formation of customized products, models, rapid prototyping, and low batch production. Forming tool and its life plays a vital role in manufacturing processing and it is directly related to productivity and production rate. The present study is concentrated on the tool wear measurement in the SPIF in which, 440C steel is utilized as forming tool and aluminum grade AA3003-O (annealed) sheet are taken as work. Further, a model is utilized for the prediction of wear and compared to measured tool wear. The measured and predicted tool wear is in the range of 0.0199 mm to 0.0379 mm and 0.0174 mm to 0.0439 mm respectively with the maximum error of 0.0330 mm in trail run 03. The overall coefficient of performance (R2) of the developed model is reported as 0.95149 and means absolute error (MAE) of −0.0048 mm.

Microstructure and stress corrosion behaviour of CMT welded AA6061 T-6 aluminium alloy joints

Superior properties of AA6061 grade aluminium alloys are finding greater use in automotive, marine and aircraft applications due to its strength, weldability and high corrosion resistance. But it is highly susceptible to stress corrosion cracking owing to alter the phase composition and microstructure during welding process. In the present work, an experimental study of stress corrosion cracking is conducted on Cold Metal Transfer welded aluminium alloy joints using various heat input under constant stress intensity to understand the susceptibility of various zones to Stress Corrosion Cracking and the performance has been analysed using Tafel electrochemical technique. The result shows that the mechanism of cracking is established to be anodic mode with transgranular nature of crack propagation. In addition, a linear relationship is also inferred to predict the time to failure by extrapolating the rate of steady state elongation. The integrity of the dissimilar joints are analysed with the help of Optical Microscopy, SEM, EDAX and XRD sophisticated analytical techniques.

Thermodynamic and kinetic analysis of CrB2 and VB2 formation in molten Al–Cr–V–B alloy

Transition metal impurities such as chromium (Cr) and vanadium (V) in solution deteriorate electrical conductivity of smelter grade aluminium (Al). These impurities can be removed from solution via boron treatment in which borides form upon their in-situ reaction with boron (B)-bearing substances. However, Cr removal from smelter grade Al solution is not well understood. A disagreement related to chromium boride (CrB2) formation in molten Al in the presence of other transition metals (V, Ti, Zr, Fe) by adding Al–B master alloy has been reported in literatures. This study presents an effort to understand the mechanism of Cr removal from Al–0.50%Cr–0.50%V (mass fraction) alloy by adding Al–B (AlB12) master alloy at 1023 K in the Al alloy solution. Results indicate that Cr removal from molten Al–0.50%Cr–0.50%V alloy by forming stable borides cannot be achieved at 1023 K; whereas excess of B in the solution preferentially forms aluminium boride (AlB2) over CrB2 during boron treatment of molten Al. The underlying kinetics of V removal from molten Al–0.50%Cr–0.50%V alloy revealed that early reaction stage is controlled by [B]/[V] mass transfer through liquid phase and mass transfer coefficient (km) was measured to be 9.6×10−4 m/s. The later reaction stage was controlled by [B]/[V] diffusion through boride (VB2) ring. This study, therefore, advocates to investigate alternative ways to remove Cr from molten Al.

Rotating arc welding of AA8090–AA2050: microstructure and mechanical properties

In this study, two grades of Aluminium–Lithium alloys: AA8090 and AA2050 have been selected. Butt joints were produced using the Rotating arc welding process (SpinArc™) with ER4043 filler. Two different groove joints, Square Butt and V-Groove, were used during the process. The joints were subjected to analysis of microstructure, mechanical properties and electronic work function. A correlation was brought out between all these tests. The microstructure analysis showed the formation of Mg2Si and Al2Cu eutectics. It was also found that the joint made using the Square Butt joint exhibited greater weld strength and enhanced work function. Electron microscopy and XRD analysis revealed the presence of different strengthening precipitates at various zones.

Numerical Investigation into In-Plane Crushing of Tube-Reinforced Damaged 5052 Aerospace Grade Aluminum Alloy Honeycomb Panels.

This paper aims to investigate the crashworthiness performance degradation of a damaged 5052 aluminum honeycomb panels under in-plane uniaxial quasi-static compression and the possibility of improving it using reinforcement tubes. The in-plane crushing behaviors and energy absorption capacities of the intact, damaged, and tube-reinforced damaged panels with different damage sizes in both X1 and X2 directions are numerically simulated by using the nonlinear FE method Abaqus/Explicit, and the crashworthiness performances are compared with each other. The validation of finite element model involves comparing the obtained simulation results with theoretical and experimental ones. Very good agreement between numerical, experimental, and theoretical results is achieved. The first maximum compressive load and the mean crushing load of the different honeycomb configurations are analyzed and compared through the load–strain curves. The energy absorption capacity of the damaged and the tube-reinforced damaged panels is calculated and then compared with their corresponding intact ones. The deformation modes are explained in detail. The obtained results show that the crashworthiness performance degradation is directly proportional to the damage size as well as the insertion of reinforcement tubes considerably improves in-plane crushing resistance of damaged honeycomb panels.

Design of a radial ultrasonic horn for plastic welding using finite element analysis

In this paper, a radial ultrasonic horn is designed by finite element analysis. Three different modes are obtained corresponding to specific natural frequencies. The distribution of amplitude and stresses of resonant mode shape are investigated. The 7075 aluminum grade is utilized for fabricating the radial ultrasonic horn. The ultrasonic sewing machine using the radial horn is established. The measured frequencies of the simulated and machined results are compared. Two kinds of polyvinyl chloride (PVC) tarpaulin fabrics with densities of 220 g sqm−1 and 320 g sqm−1 are welded by the radial ultrasonic welding system. Two patterns of the rollers are utilized for testing the welding ability of the machine. The ultrasonic power, air pressure, and the velocity of the roller are set at 1500 W, 3 kg cm−2, and 6 m min−1, respectively. Good welding joints are achieved. The tensile strengths of welding joints of two tarpaulin sheets are measured as 144.9 g mm−1 and 134.6 g mm−1, respectively.

Mixed-Phase Ion-Exchangers from Waste Amber Container Glass.

This study investigated the one-pot hydrothermal synthesis of mixed-phase ion-exchangers from waste amber container glass and three different aluminium sources (Si/Al = 2) in 4.5 M NaOH(aq) at 100 °C. Reaction products were characterised by X-ray diffraction analysis, Fourier transform infrared spectroscopy, 27Al and 29Si magic angle spinning nuclear magnetic resonance spectroscopy and scanning electron microscopy at 24, 48 and 150 h. Nitrated forms of cancrinite and sodalite were the predominant products obtained with reagent grade aluminium nitrate (Al(NO3)3∙9H2O). Waste aluminium foil gave rise to sodalite, tobermorite and zeolite Na-P1 as major phases; and the principal products arising from amorphous aluminium hydroxide waste were sodalite, tobermorite and zeolite A. Minor proportions of the hydrogarnet, katoite, and calcite were also present in each sample. In each case, crystallisation was incomplete and products of 52, 65 and 49% crystallinity were obtained at 150 h for the samples prepared with aluminium nitrate (AN-150), aluminium foil (AF-150) and amorphous aluminium hydroxide waste (AH-150), respectively. Batch Pb2+-uptake (~100 mg g−1) was similar for all 150-h samples irrespective of the nature of the aluminium reagent and composition of the product. Batch Cd2+-uptakes of AF-150 (54 mg g−1) and AH-150 (48 mg g−1) were greater than that of AN-150 (36 mg g−1) indicating that the sodalite- and tobermorite-rich products exhibited a superior affinity for Cd2+ ions. The observed Pb2+- and Cd2+-uptake capacities of the mixed-product ion-exchangers compared favourably with those of other inorganic waste-derived sorbents reported in the literature.

Microstructure analysis of AA6082/Si3N4 and AA6082/SiC composites

PurposeParts that are to be used in aircraft, satellites, automobiles and ships should have sound microstructure. Components made from AA6082/Si3N4 and AA6082/SiC composites are in demand from industries. Hence, these components are to be fabricated by suitable technique at the appropriate value of process parameters. The purpose of this paper is Microstructure analysis of AA6082/Si3N4 and AA6082/SiC compositesDesign/methodology/approachAA6082/Si3N4 and AA6082/SiC composites are successfully fabricated using the stir casting process. Their microstructures have been analyzed. This has been done at different magnification. The effect of the addition of Si3N4 and SiC particles in the 6082 aluminum alloy is investigated. Microstructure of AA6082/Si3N4 and AA6082/SiC composites are also compared. Results show that Si3N4 and SiC particles have good wettability with AA6082. These reinforcement particles are homogeneously distributed in the matrix of AA6082.FindingsThere are no adverse effects of reactions in the microstructure of AA6082/Si3N4 and AA6082/SiC composites. There is not much difference between the distribution and interfacial characteristics of Si3N4 and SiC particles. AA6082/Si3N4 and AA6082/SiC composites have good properties. This is high strength at low density. Due to which they become suitable for the aircraft and space industry. So far, SiC, Al2O3 and tungsten carbide have been mostly used as reinforcements with different grades of aluminum alloy.Originality/valueNot much experimental work is found with Si3N4 and SiC particles as reinforcement with AA6082. The novelty of this research work is that an effort has been made to fabricate AA6082/Si3N4 and AA6082/SiC composites at such values of process parameters, by stir casting process, so that sound and defect free microstructure is obtained. Microstructure of AA6082/Si3N4 and AA6082/SiC composites is also compared, to find which is better.