Grade Aluminum Research Articles

A Critical Assessment on Rotary Friction Welded High Strength Armor Grade Aluminum Alloy Joints

A Critical Assessment on Rotary Friction Welded High Strength Armor Grade Aluminum Alloy Joints

An experimental investigation of mechanical properties, forming limit curves, and bending behavior of aluminum-polymer sandwich composites

This study aimed to investigate the forming limit diagrams (FLDs), mechanical properties, and bending behavior of the three kinds of sandwich composites. The core layer in all sandwich sheets consisted of polyethylene, and just the skin layers were chosen to be AA5754 or AA3105. The results showed that the sandwich sheets are an appropriate choice to be used instead of the monometallic sheets. According to the 3-point bending test results, the flexural strength of the AL 3105/Polyethylene/AL 3105 sandwich composite is about 30 percent less than the AA3105 monometallic layer. Also, the formability of the metallic sandwich composites with non-identical skin layers was studied. The results demonstrated that using one layer AA 3105 and one layer AA5754 instead of AA5754 for both skin layers, although formability decreased about 11% in the plane strain region, the cost of fabricating the composite was decreased sheet reduces almost 75%. As a result, using skin layers with the different grades of aluminum is an appropriate way to reduce the cost of fabricating the aluminum-polymer sandwich composites, in which the formability does not decrease significantly.

Microstructure, Tensile and Flexural Strength of Boron Carbide Particles Reinforced Al2030 Alloy Composites

Objective: To synthesize and assess the mechanical behaviour of 12 wt. % of 80 to 90 micron sized B4C reinforced Al2030 alloy metal composites. Method: Al2030 alloy with 12 wt. % of B4C reinforced composites were developed by liquid melt stir cast method. These prepared composites were subjected to microstructural characterization by SEM, EDS and XRD. Mechanical properties like hardness, tensile and flexural strength were evaluated according to ASTM standards. Findings: Scanning electron micrograph of Al2030 alloy with 12 wt. % of B4C composites revealed the thorough distribution of boron carbide particles in the Al2030 matrix. EDS and X-ray diffractometer patterns confirmed the presence of boron carbide particles in the Al2030 alloy matrix. The addition of 12 wt. % of B4C particles enhanced the hardness by 74.8%, ultimate strength by 59.2%, yield strength by 64.8% and flexural strength by 44.2% with slight decrease in ductility. Novelty: Al2030 alloy is an aerospace grade aluminium alloy widely used for industrial applications. Advanced metal composites developed with the incorporation of 80 to 90 micron sized B4C particles in Al2030 alloy helps in weight reduction of aerospace components. Keywords: Al2030 Alloy; B 4 C Particles; Microstructure; Tensile Strength; Flexural Strength; Fractography

Development and evaluation of barnyard millet instant dosa mix

Instant mixes offer great convenience to the homemakers to prepare traditional delicacies. It reduces the time and drudgery associated with the preparation. The present study aimed to at standardization of barnyard millet instant dosa mix. The impact of barnyard millet flour incorporation on sensory characteristics and shelf life of instant dosa mix was studied. Instant barnyard dosa mix with 50 per cent of barnyard millet flour was finalisedand assessed for shelf life. The particle size distribution of barnyard millet dosa mix and cooking characteristics of best accepted variation was carried out using standard procedures.The results revealed that, as millet flour increased, the thickness of dosa decreased and diameterwas increased, resulting in increased spread ratio.The nutrition composition of 100 g barnyard millet instant dosa mix contains9.50 % moisture, 12.67 % protein, 2.64 % fat, 1.81 % crude fibre,2.57 % ash, 72.62 %carbohydrates, 4.93 mg of iron, 2.21 mg of zinc and 23.94 mg of calcium. From storage study it is evident that the barnyard millet instant dosa mix stored in food grade aluminum foil pouches at ambient temperature can be stored for four and half months.

A General Expression for the Welding Tendon Force

Abstract This study presents a novel expression for the tendon force associated with residual stresses produced during welding of large, thin sections. A general engineering equation is presented as the combination of a closed-form expression, based on idealized treatment, and correction factors to account for the effects of temperature-dependent thermal and mechanical material properties. The closed-form expression corresponds to the assumption of constant material properties. A rigorous mathematical treatment is utilized to derive explicit, exact expressions for the temperature-dependent correction factors without the need for empirical correlations. The temperature-dependent behavior of materials is captured accurately using four dimensionless groups. The analysis was validated through numerical simulations with common structural grades of low-carbon steel, stainless steel, aluminum, and titanium. The idealized treatment resulted in predictions with a mean difference of 18%, which was reduced to 7% by incorporating the correction factors. The remaining error is a systematic overestimate, which can be attributed to compliance effects of the finite plate used in the simulations, and is the focus of ongoing research. The utility of applying the novel tendon force equation to problems in fabrication procedure design is demonstrated with an example predicting distortion during manufacturing of hollow structural sections.

Internal Flow Behaviour and Microstructural Evolution of the Bobbin-FSW Welds: Thermomechanical Comparison between 1xxx and 3xxx Aluminium Grades

Abstract The influences of processing parameters and tool feature on the microstructure of AA1100 and AA3003 aluminium alloys were investigated using bobbin friction stir welding (BFSW). The research includes flow visualization and microstructural evolution of the weld texture using the metallographic measurement method. Results indicated that the operational parameters of the welding (e.g. feed rate, rotating speed) and the geometry of the tool can directly affect the flow patterns of the weld structure. The microscopic details revealed by the optical and electron microscope imply the dynamic recrystallization including grain refinement and precipitation mechanisms within the stirring zone of the weld region. The microscopic observations for the weld samples show a better performance of the fully-featured tool (tri-flat threaded pin and scrolled shoulders) compared to the simple tool without inscribed surface features. The fully-featured tool resulted in a more uniform thermomechanical plastic deformation within the weld structure along with the precipitation hardening and the homogeneity of the microstructure.

Manufacturing of cylindrical articles with a thick bottom and thin wall

The issue of increasing the efficiency of metal forming processes by combining the operations of drawing with thinning of the wall and extrusion in the manufacture of cylindrical articles having a thick bottom and thin wall. The ratio of height to diameter can vary from 1 to 10 and more. These are various connectins, adapters, unions, elements of cases, sleeves and other articles with a wall thickness less, than thickness of a bottom. Rolled sheet metal made of various grades of steel, brass, aluminum, titanium and other materials can be used as workpiece materials. The combination of drawing operations with wall thinning and extrusion at one working position allows to significantly expand the technological capabilities of metal forming, reduce the number of steps, improve the quality of articles. Compared to backward extrusion, the proposed technology provides a lower level of stress in the tool and workpiece, enabling to use less powerful hydraulic press equipment and significantly increase the durability of stamping equipment. When using blanks with planar anisotropy, this technology allows not only to eliminate earing on the edge surface of the semi-finished product and get a smooth face end of the product, but also to form any other profile of the edge of the part. The formation of articles without earing eliminates the operation of trimming the end face of the semi-finished product, which significantly increases the utilization of the material and reduces the cost of finished articles. The method for calculation of geometrical parameters of stamping equipment to obtain defect-free articles is given. Theoretical studies of the combination of drawing operations with thinning and extrusion of the cylindrical workpiece were carried out by the finite element modeling method using the QFORM software package. The scheme of universal experimental stamping equipment is shown.

Improving physical and mechanical properties of foil for anodes of high-voltage electrolytic capacitors by introducing an intermediate annealing

The results of studies of influence of intermediate and final annealing on the level of physical and mechanical properties of foil for anodes of highvoltage capacitors made of high-purity aluminum (99.99%) are presented. A comparative analytical analysis of efficiency of introduction of the intermediate annealing stage in the thermo-deformation processing mode in comparison with its absence in the scheme was performed. The starting material for the research is a strip with a thickness of 0.45 mm, obtained from hot-rolled strip with a thickness of 8 mm by cold rolling (deformation degree is 0.9437). The chemical composition of the strip corresponds to the A99 aluminum grade according to GOST 11069–2019. Content of basic impurities in the initial strip by the actual chemical composition,%: 0,0018 Si; 0.0012 Fe; 0.0020 Cu. A set of studies of physical and mechanical properties, which allowed to determine the dependence of the maximum value of specific capacity of high-voltage anode foil on the average grain size and crystallographic orientation (in this case - the maximum value of cubic texture, with allowable values of foil ultimate strength). It is shown that with an increase in the intensity of the cubic texture from 90 to 95%, the specific capacitance increases from 29 to 32 μF/dm2. This is achieved through the use of intermediate annealing at 380 оC and further final annealing at 550 оC. The hereditary character of the average grain size of samples with a thickness of 0.45 mm during intermediate annealing and the grain size of the foil with a thickness of 0.100 mm after the final annealing is shown.

Solid-state joining of aluminum to titanium: A review

The dissimilar material joining of aluminum and titanium alloys is recognized as a challenge due to the significant differences in the physical, chemical, and metallurgical properties of these alloys, where the increasing demands for high strength and lightweight alloys in aerospace, defense, and automotive industries. Joining these two alloys using the conventional fusion techniques produces commercially unacceptable sound joints due to irregular, complex weld pool shapes, cracking and low strength, high residual stresses, cracks, and microporosity, and the brittle intermetallic compounds formation leads to poor formability or inferior mechanical properties. The formation of intermetallic compounds is inevitable but it is less severe in solid-state than in the fusion welding process. Hence, this article reviews on aluminum–titanium joining using different solid-state and hybrid joining processes with emphasis on the effect of process parameters of the different processes on the weld microstructure, mechanical properties along with the type of intermetallic compounds and defects formed at the weld interface. Among the various solid-state welding processes for aluminum–titanium joining, the following grades of aluminum and titanium alloys were employed such as cp Ti, Ti6Al4V, cp Al, AA1xxx, AA 2xxx, AA5xxx, AA6xxx, AA7xxx, out of which Ti6Al4V and AA6xxx alloys are the most common combination.

Estimation of deformation behaviour at different weld zones of FSWed 2014 aluminium alloy through impression creep technique

Impression creep (IC) tests of the best-welded specimen at three dissimilar weld zones of friction stir welded (FSWed) 2014 grade aluminium alloy welded with optimized process parameters were carried out at a temperature of 310, 330 and 350 °C and stress regimes of 21, 24 and 27 MPa. The creep deformation properties of the localized zones viz: nugget zone (NZ), thermo-mechanical affected zone (TMAZ) and heat-affected zone (HAZ) of the FSWed material including the base material (BM) were revealed using the power law creep equation and correlated with the variation in microstructural properties. The steady-state creep rate of the individual zones along with the BM was analyzed. The other creep parameters such as stress exponents (n) and apparent activation energy for the IC deformation procedure (Qic ) were calculated henceforth. From the calculated n and Qic value, the creep deformation process in the BM as well as in TMAZ and HAZ of the welded material was estimated to be through dislocation glide. Whereas the NZ deforms by grain boundary sliding and this may be due to the heterogeneity in the microstructure. The micro-hardness after IC test was increased for each sample. The outcomes are concluded with the microstructural study of the creep tested sample through optical and field emission scanning electron microscope. The particles agglomeration and dislocation structures at NZ were confirmed by transmission electron microscope (TEM). To observe the composition influence of the precipitated second phase particles on creep behaviour, an energy dispersive x-ray study was also carried out.

A multiaxial fatigue life prediction method for metallic material under combined random vibration loading and mean stress loading in the frequency domain

A spectral method for the determination of the critical plane is proposed for metallic material under random vibration loadings based on the criterion of maximum shear stress amplitude, where the direction of critical plane is obtained by solving the maximum value of a function using mathematical optimization method and the fatigue critical location of the structure can be determined. A multiaxial fatigue damage parameter is proposed for combined random vibration loading and mean stress loading cases based on Susmel’s criterion, which is a Power Spectral Density (PSD) of the equivalent shear stress and can be adopted for fatigue life evaluation. The fatigue life estimation of structures under multiaxial random vibration loadings with mean stresses in the frequency domain could be carried out based on this damage parameter constructed at the fatigue critical location with the spectral method for random vibration fatigue life. The multiaxial random vibration fatigue experiment with mean stress loadings is conducted on the notched plate specimens made of 2297-T87 aviation grade aluminum alloy, and the initiation sites of the fatigue cracks as well as the experimental fatigue lives are compared with those calculated by the proposed models, where satisfactory prediction capabilities on both the fatigue crack initiation locations and fatigue lives of the models are demonstrated.

The effect of the concentration of vanadium pentoxide hydrogel applied on ASD-4 grade aluminum on its structural and adsorption properties

The effect of the concentration of vanadium pentoxide hydrogel applied on ASD-4 grade aluminum on its structural and adsorption properties

Heterogeneous microstructure and deformation behavior of an automotive grade aluminum alloy

Aluminum alloy is today considered as a prime selection for manufacturing lightweight structural components in the automotive industry to increase fuel efficiency and reduce harmful emissions. The aim of this study was to identify the effect of microstructure and strain rate on the tensile deformation behavior of a high-pressure die-cast Silafont®-36 alloy, with special attention to strain hardening behavior and deformation mechanisms. The alloy consisted of randomly oriented primary α-Al phase and Al–Si eutectic structure in a form of heterogeneous microstructures, with Sr-modified Si particles exhibiting a coral-like fibrous network. The local misorientations in most primary α-Al grains was below 1°, suggesting strain-free grains along with some extent of near-boundary residual strains due to the thermal mismatch between aluminum and silicon. A superior strength-ductility combination was achieved, along with enhanced Young’s modulus and quality index owing to the unique heterogeneous microstructures. The cast alloy exhibited a smooth deformation characteristic with good coordination deformation and strong strain hardening capacity. Strain hardening exponents evaluated via the equations proposed by Ludwik, Hollomon, Swift, and Afrin et al., respectively, showed basically the absence of strain-rate effect from 1 × 10−5 to 1 × 10−2 s−1. During the tensile deformation, crack initiated from the sample surface and propagated through the alternate microconstituents of softer primary α-Al phase and harder eutectic structure.

Effect of dispersing CTBN into Diglycidyl Ether of Bisphenol-A on Mixed mode Loading

Delamination of polymer composite is one of the major failure characteristic, in this context the fracture behavior of the tailored composites in combination of opening mode and shearing mode is assessed and its fracture robustness of the glass fiber reinforced laminate are determined experimentally, in this present work by developing a modified Arcan fixture using a single edge notched specimen for characterizing in various loading conditions, The fixture was made of industrial grade Aluminum ingot machined to an outer diameter of 150 mm, having a thickness of 10 mm. The fixture had provision to load the sample at different oblique angles up to 90 degrees in steps of 15 degrees. The samples were attached to the fixture by means of fasteners and were tested in tensile mode using a 40 KN Instron tensile tester at constant displacement and ambient conditions. Further, the resin was strengthened with Carboxyl Terminated Butadiene Arenonitrile (CTBN) and its effect on fracture parameters was studied by varying the loading angles. Results indicate that the fracture parameters vary with loading and at angles greater than 45 degrees, the GFRP sample’s behavior changes from opening mode to shearing mode and the converse is also true. This pattern is similar, with the specimens even after modifying the resin with CTBN however, it was found that stress intensity factor increased corresponding to the increase of CTBN infusion. CTBN was dispersed into the Bisphenol base A (LY566– A general purpose thermoset epoxy resin) in three different percent: 1%, 3% and 5% by weight. The layup sequence used in this work was cross ply. The effect of varying the loading angles on the stress intensity factors were studied.

About the possibility of identification of articles from steels, aluminum, copper and alloys on their basis on the expanded micro-impurity elemental composition

Possibility of determination of the fragments and articles made of different grades of steel aluminium and copper alloys and their affiliation to the common melt was examined via the methods of photoelectric spectral analysis based on composition of micro-impurities. Chemical elements with micro-impurities were revealed; they allow to determine affiliation of metal fragments to one melt. Ultimately possible deviations of micro-impurities within one melt were obtained. The technique allowing to establish affiliation of fragments to the common melt based on their elementary composition of micro-impurities with minimal amount of measurements was suggested based on the obtained results. The minimal geometric size of a sample available for analysis was determined; it allows to classify the examined fragments to one melt based on the results of investigation of expanded elementary composition of micro-impurities. Practical opportunities of this technique were displayed on the example of the alloys with different chemical composition.

Microsecond Laser Texturing of an Aerospace Grade Aluminum Alloy to Synthesize Superhydrophobic, Anti-Water Clogging Surfaces

Traditionally superhydrophobic surfaces are prepared by applying liquid repellant organic coatings or nano-based coatings. These superhydrophobic coatings are prone to wear and can be easily damaged by abrasion and cleaning. Recently researchers are switching interest to more efficient and promising technology of pulse laser texturing for engineering sub-micron topographies to have superhydrophobic surfaces. In this research, the micro-second Laser Pulses are used to feature sub-micron textures on titanium nitride coated aluminum and polished aluminum surfaces in order to achieve the water contact angle greater than 150°. Titanium nitride coated aluminum surface with scan line separation of 50 µm shows superior hydrophobicity having a water contact angle of 156º. These superhydrophobic aluminum surfaces have applications for anti-water clogging and anti-corrosion use.

Influence of SiC Particles on Mechanical and Microstructural Properties of Modified Interlock Friction Stir Weld Lap Joint for Automotive Grade Aluminium Alloy

The present requirement of the aerospace industry is seeking light-weight joining material that satisfies the technical and technological requirements with better mechanical characteristics. Aluminum alloy with spot-welding process meet the requirements of modern demands. In this present paper, a modified-interlock friction stir weld lap joint is induced to join AA8011-AA7475 with different wt% of SiC particles. Friction stir machine process parameters were tool rotational speed 1600 rpm, plunge speed rate 0.08 mm/s and traverse speed 40 mm/s maintained constantly. Mechanical and metallurgical characterizations were investigated. EDS analysis and microstructure confirmed the presence of silica particles in the NZ of the weld joints and uniformed homogenous distribution of the particulates throughout the weld. Joints made with SiC particulates showed improved static properties because intensive softening occurred in the stir zone leading to Si-Al-based precipitate particulates. The fracture test showed that the joints with SiC had a ductile fracture. AA8011-AA7475 with 2 wt% SiC showed maximum hardness, tensile strength of 229 HV, 192 MPa and a decrease in elongation was observed from 9.5 to 5%. AA8011-AA7475/2 wt% showed improved hardness, tensile strength and elongation suitable for aircraft wing stringers application.

Residual stress analysis of friction stir welded AA6063 pipe butt joint by neutron diffraction technique of ENGIN-X

Residual stress refers to stress that remains in a structure when all applied stresses have been removed. It is important because the combination with applied stress can cause failure at the level below at which the failure could occur. A study has been carried out using the non-destructive neutron diffraction (ND) technique of ENGIN-X to quantify the redistribution of residual stresses in a pipe. A three-dimensional residual stress-measurements test is fully performed on a 89 mm (3.5 in) diameter pipe in AA6063 grade aluminium (5 mm wall thickness) containing a girth friction stir weld. The results have shown an opposite residual stress effect due to tool rotational speed increment especially on the retreating side of the weld. This weld residual stress analysis is an important factor for Fitness-For-Purpose Assessments. This residual stress measurement data provides a basis for structural integrity assessment and inspection planning.

Understanding the process of making fuse contacts by upsetting of aluminium bars

This paper describes the results of a study that looked at an innovative wastefree process of cold upsetting to make power fuse contacts from the commercial aluminium grade AD1. The process involves upsetting and extrusion of a workpiece cut from steel bar stock in the same die in one process step. It is proposed to use this process instead of making each separate fuse contact part, i.e. when the fuse base and the knife are notched out of a steel bar and are then stamped together. The new process is less labour intensive due to less pieces of die tooling used, less equipment required, less personnel involved and due to a significantly higher metal utilization factor – 1 instead of 0.7. Solid models have been developed for the solid part of fuse contact and for the die tooling so that this process could be performed in a die. A procedure has been developed for making fuse contacts by cutting a steel bar in the die with a flat end punch followed by upsetting and extrusion of the workpiece. The dimensions of the primary blank and the forces acting at different process steps have been determined. The upper-bound method was applied to conduct a theoretical study of kinematic parameters and forces involved in the process. Physical and mathematical modelling helped establish how a steel bar changes its shape under upsetting and extrusion. Having analyzed the block models of the extrusion process with kinematically possible velocity fields, the authors identified what conditions lead to defect formation and offered some measures to prevent such defects. Force-geometry relationships have been defined. Experimental die tooling has been made and a prototype die – designed to implement this process in practice. A pilot batch of fuse contacts has been produced.

Optimization of process parameters of friction stir welded joints of marine grade AA 5083

Abstract Friction Stir Welding is an innovative solid-state joining technique commonly utilized in industries. It is a combination of highly multifaceted process utilizing several coupled mechanisms. Although, large number of researchers are working in this field to reveal the maturity of the process evolving many plausible application and materials. Still the process needs intensive study to optimize production procedures that will yield high quality stronger welds from the stirring action of the tool and pin into the weld plate material. In this part of the research the study to know the influence process parameters and tool pin geometry on friction stir welding (FSW) of marine grade aluminium (5083) especially in reference to microstructure and mechanical properties of weld has been highlighted so as to optimize the welding parameters along with the tool geometry. Tensile properties of the joints have been studied and their correlations with the process parameters along with the tool parameters have been investigated. The highest joint efficiency of 75.67% efficiency with the ultimate tensile strength (UTS) of 212 MPa was noted in the case of FSW joint fabricated by T1 tool with 1000 rotational speed and 28 mm per minute of welding speed. Also, microstructures of various zones of FSW sample have been evolved and correlated with the process parameters which explains the dynamic recrystallization process at the nugget zone of FSW joint.