Aluminum Laminates Research Articles

Design of pure aluminum laminates with heterostructures for extraordinary strength-ductility synergy

• Pure aluminum laminates with various heterostructures were engineered via extrusion, rolling and annealing. • The designed laminates exhibited an excellent strength-ductility synergy. • The evolution of GNDs was observed using in-situ tension. • The strain gradient across the hetero-interface was revealed using DIC technique. • Hetero-deformation induced (HDI) strengthening and hardening contributed to the superior mechanical properties. Heterogeneous metals and alloys are a new class of materials with superior mechanical properties. In this paper, we engineered sandwich-structured pure aluminum laminates composed of middle coarse-grained layer and outer fine-grained layer via extrusion, rolling and annealing. By controlling the post-annealing regimes, a larger degree of microstructure heterogeneities such as boundary spacing, misorientation and texture across the hetero-interface were obtained, which resulted in obvious mechanical differences. Tensile tests indicated that the 300 °C/30 min annealed laminates enabled a relatively high tensile ductility while simultaneously retaining a high strength, which was better than prediction by the rule-of-mixture. To explain the reasons behind it, the evolution of geometrically necessary dislocations and strain gradient at the hetero-interface zone were detected using in-situ tension and microscopic digital image correlation technique. It was found that with the increasing applied strain, a significant strain gradient was developed near the interface, which was accommodated by geometrically necessary dislocations, thereby contributing to higher hetero-deformation induced (HDI) strengthening and hardening.

Optimization of delamination resistance of vacuum infused glass laminate aluminum reinforced epoxy (GLARE) using various surface preparation techniques

GLARE (glass-reinforced fibre–metal laminate ) is aluminum based material of fiber metal laminate (henceforth FML) that is often fabricated by expensive autoclave procedure. In this study, the process of Injected Molding or (also known as VARTM was employed as a cost-effective alternative to produce GLARE. Several aluminum surface preparation procedures are applied to improve the interlaminar shear strength. A T3 temper 2024 aluminum alloy with 1*1 plain fabricated glass fabrics were used to make GLARE composites. GLARE consists of two aluminum sheet as external layer and glass fabric as internal layers. Four sets of aluminum sheets were prepared, one unanodized and three other anodized. Three different anodizing procedures (constant voltage mode, increasing voltage mode and decreasing voltage mode) have been adopted in this research. Two types of curing treatments were applied on VARTM fabricated specimens. According to ASTM D1876 T-peel test standard, the sets of prepared specimens have been tested to examine the adhesive bonding strength and fracture toughness of mode-I. The obtained results which include force-displacement curves, peak loads and fracture toughness were showed that a significant improvement for anodized specimens with all voltage modes. The first curing treatment offered better results than second curing treatment. The best improvement was obtained from anodized specimen with decreasing voltage mode cured by the first treatment which reaches to six times the results obtained from unanodized specimen. The delamination behavior for this specimen was verified numerically.

Bonding Characteristics of Aluminium Laminates and Aluminium-Graphite Composites Processed by Roll Bonding

Bonding Characteristics of Aluminium Laminates and Aluminium-Graphite Composites Processed by Roll Bonding

Development of a passive exercise device to turn the forearm pronation and supination using pneumatic soft actuators

The symptoms of joint range of motion limitation make life difficult and aggravate quality of life. Usually, physical therapists provide rehabilitation training to prevent it. In this study, we have developed a passive motion device for pronation and supination of the forearm. This paper describes the prototype and the evaluation test of the device. We used a pneumatic soft actuator that can press directly on the affected area to develop the device. The pneumatic soft actuator consists of aluminum laminate films and an air supply tube. The device performs these motions for the forearm by the actuator directly pushing the wrist. In the evaluation test, the force generated by the pneumatic soft actuator was measured and we had a questionnaire about performance of the device from 10 subjects. The all subjects were able to perform passive movements of internal and external rotation of the arms. The tests also revealed that the device could allow the subjects to move otherwise from 60% to 80% of their reference range of motion.

Pengaruh Perlakuan Permukaan Pengikatan Terhadap Sifat Mekanik Komposit Serat Kaca Dengan Laminasi Almunium

Fiber metal laminates or commonly known as fiber metal laminates (FML) are composite structures made by combining 2 layers of material as the outer layer with the core material. The outer layer of this composite is called the laminate. Generally, laminated composites are produced by joining techniques under solid-state conditions, such as diffusion bonding, extrusion, friction-stir welding, and roller welding. In this study, glass fiber composites with aluminum lamination were made using the vacuum assisted resin infusion (VARI) method, using epoxy resin. The surface treatment of the aluminum laminate was carried out with the direction of roughing at certain angles and variations of the surface roughening of the laminate to test the mechanical bonding between the composite and the laminate. Mechanical bonding testing using three-point bending test method (three-point bending) and buckling test. The expected result is that by surface treatment on aluminum laminate, the best mechanical bonding to composites with glass fiber is obtained. The TKT to be achieved from this research is TKT level 3, which is an analytical study that supports the prediction of the performance of the effect of the bonding surface treatment on the mechanical properties of glass fiber composites with aluminum lamination.

Deterministic and probabilistic buckling response of fiber–metal laminate panels under uniaxial compression

PurposeThe purpose of this paper is to study the deterministic elastic buckling behavior of cylindrical fiber–metal laminate panels subjected to uniaxial compressive loading and the investigation of GLAss fiber-REinforced aluminum laminate (GLARE) panels using probabilistic finite element method (FEM) analysis.Design/methodology/approachThe FEM in combination with the eigenvalue buckling analysis is used for the construction of buckling coefficient–curvature parameter diagrams of seven fiber–metal laminate grades, three glass-fiber composites and monolithic 2024-T3 aluminum. The influences of uncertainties concerning material properties and laminate dimensions on the buckling load are studied with sensitivity analyses.FindingsIt is found that aluminum has a stronger impact on the buckling behavior of the fiber–metal laminate panels than their constituent uni-directional or woven composites. For the classical simply supported boundary conditions, it is found that there is an approximately linear relation between the buckling coefficient and the curvature parameter when the diagrams are plotted in double logarithmic scale. The probabilistic calculations demonstrate that there is a considerable probability to overestimate the buckling load of GLARE panels with deterministic calculations.Originality/valueIn this study, the deterministic and probabilistic buckling response of fiber metal laminate panels is investigated. It is shown that realistic structural uncertainties could substantially affect the buckling strength of aerospace components.

Creep Age Forming of Fiber Metal Laminates: Effects of Process Time and Temperature and Stacking Sequence of Core Material.

Fiber metal laminates (FMLs) are a type of hybrid materials interlacing composites and metals. In the present work, FMLs with aluminum alloy 6061 as the skin and E-glass fiber-reinforced polypropylene (PP) as the core material are fabricated and formed by the creep age forming (CAF) process. The effects of time and temperature as the process parameters and thickness and stacking sequences of composites layers as the FML parameters are evaluated on the springback of glass-reinforced aluminum laminates (GLARE) FMLs. After the CAF process, the springback of creep age-formed FMLs is calculated. The results show that the FMLs can be successfully formed with the CAF process by considering appropriate time and temperature. In addition, the stacking sequence of composite layers can affect the springback behavior of FMLs significantly.

Studying the effect of tomato pomace incorporation on physicochemical, nutritional and storage characteristics of corn-based extrudates using response surface approach

PurposeThe present research was envisaged with an aim to optimize the system and the product responses for the development of tomato pomace-incorporated corn-based extrudates employing central composite rotatable design and determine its proximate, lycopene, consumer acceptability and storage studies.Design/methodology/approachLycopene-rich extrudates were developed from corn flour blended with different levels of tomato pomace. The independent extrusion variables, namely, feed composition (95:5 to 75:25), feed moisture (12–20%), screw speed (200–600 rpm) and barrel temperature (125–185 °C), were studied to determine their influence on dependent variables, namely, specific mechanical energy, hardness, water solubility index, lateral expansion, water absorption index, bulk density and color.FindingsAll of the quality parameters were significantly (p < 0.05) influenced by independent variables. The regression models obtained for all the responses showed high coefficients of determination (R2 = 0.85–0.95). The optimum conditions for the development of tomato pomace-incorporated corn-based extrudates were feed composition (90:10), feed moisture (14%), screw speed (300 rpm) and barrel temperature (170 °C). The moisture, fat and carbohydrate contents of the extrudates were significantly reduced, whereas protein, ash and fiber were significantly (p < 0.05) enhanced after the incorporation of tomato pomace. Aluminum laminates were found to be the suitable packaging materials for extrudates for a period of 120 days in comparison to high-density polyethylene packages.Originality/valueAs far as the authors could possibly know, scanty literature exists wherein the tomato pomace has been utilized for the development of lycopene-rich corn-based extruded snacks. Such extrudates with significantly higher fiber and lycopene contents than corn flour will serve as a suitable alternative for the development of shelf-stable ready-to-eat extruded snacks.

Improvement of the Mechanical Characteristics of Fiber Metal Laminate (FMLs) Used for Aircraft Wing Using Epoxy-Resole

The Fiber Metal Laminates (FMLs) was studied and improved the mechanical properties were used for aircraft wing. The FMLs are consisting of metal sheets reinforced with fiber bonded by matrix phase. The FMLs consist of seven layers to produce the Hybrid composite materials that made from 2024-T3 Aluminuim sheets with carbon and glass fibers as reinforcement and bonded using adhesion materials that are locally manufactured from resole resin with adding using epoxy resin. By using the FMLs, the mechanical characteristics have been improved and the weight of the aircraft wing has been reduced. The mechanical characteristics have been improved comparing to other FMLs using commercial epoxy. The FMLs with carbon and glass fibers have high tensile strength and elastic modulus but low yield and elongation comparing with the FMLs of carbon fibers as a reinforcement. The flexural modulus and impact toughness is high for the FMLs with glass fiber comparing with jute fibers with adding using carbon fiber as areinforcement.The Aramid Reinforced Aluminum Laminates (ARALLs) have low fatigue strength than FMLs using carbon fiber as reinforcement. The FMLs are lower ratio of ultimate to yield strength and density than 2024-T3 Aluminum alloy that commonly used in aircraft wing.

An inter-ply friction model for thermoset based fibre metal laminate in a hot-pressing process

Forming process with pre-stacked and uncured thermoset fibre metal laminate offers improved deformability compared to full-cured laminate especially for the production of complex structural components. This work investigated the friction behaviour at the metal-prepreg interface of glass fibre reinforced aluminium laminate through an inter-ply friction test. The influence of sliding velocity, normal force, fibre orientation and resin viscosity coupled with temperature on static and kinetic friction coefficients were studied. The kinetic friction behavior in the transition region between mixed and hydrodynamic lubrication, showed a good agreement with the Stribeck-curve theory. While for the static friction, a modified Coulomb friction model was found to fit the experimental results. These models were translated into a phenomenological inter-ply friction model which was incorporated into Abaqus/Explicit as a user-defined friction subroutine for verification. The findings contribute to the development of the forming process with fibre metal laminates.

Influence of Aluminum wire mesh location through stacking sequence on mechanical properties of GFRE composite laminates

Glass laminate aluminum reinforced epoxy (GLARE) mixes a layer of aluminum with fiber-reinforced epoxy to constitute a hybrid composite. During this investigation, plain E-glass fiber/epoxy specimen in addition to hybrid composite laminated epoxy specimens reinforced with both E-glass fiber and wire meshes of aluminum were produced. Tensile, bending, and hardness tests were performed to investigate how inserting Al wire meshes through thickness of the specimen in place of glass fiber layers affected the material mechanical characteristics. The characteristics of the generated hybrid laminates represented by strength and ductility were greatly influenced by varying the position and orienting direction of the aluminum wire mesh ply. Inclusion of Al wire mesh in the outer layers significantly causes deterioration in material tensile and bending strengths. The tensile strain as well as bending strain, on the other hand, were improved as a result of incorporating Al wire meshes by 51.3 percent and 153.4 percent, respectively.

Drilling and helical milling for hole making in multi-material carbon reinforced aluminum laminates

Dissimilar properties of the constituent materials in Fiber Metal Laminates (FMLs) make hole making a demanding task. Improper selection of the process and the process parameters can result in poor surface quality, dimensional inaccuracy, or even failure of the component. The work, therefore, compares the drilling and helical milling process for hole-making in carbon fiber aluminum laminates (CARALL). The comparison was carried out by evaluating the machining forces, chip morphology, machining temperature, surface roughness, hole size, and burr size. The experimental results revealed significantly lower machining forces and machining temperature during helical milling. Utilization of helical milling for hole making resulted in the production of holes within H9 diameter tolerance. Substantial reduction in the surface roughness was noted during helical milling by virtue of the discontinuous chips generated during the process. Furthermore, holes processed using helical milling showed relatively smaller-sized burrs in comparison to the drilling process. Overall, the initial evaluation exhibits the positive capability of helical milling for hole-making in CARALL FMLs.

Comprehensive experimental investigation on drilling multi-material carbon fiber reinforced aluminium laminates

The amalgamation of metallic alloys and fiber-reinforced composites has helped Fiber Metal Laminates (FMLs) like Carbon fiber reinforced aluminum laminates (CARALL), and Glasslaminatealuminum-reinforced epoxy (GLARE) overcome the limitations of standalone metals and composites. As a result, they have found increasing applications in the aircraft and defense industries. Moreover, the inhomogeneous nature and poor machinability of the materials make hole drilling challenging. Therefore, to enhance drilling performance, the paper reports a systematic analysis of the effect of spindle speed and axial feed on key performance measures, including thrust force, machining temperature, surface roughness, hole size, burr size, and chip morphology. Experimental outcomes indicate a significant reduction in the thrust force while utilizing higher spindle speed (4000 rev/min) and lower axial feed (0.1 mm/rev), while the surface finishes improved under high feed conditions (0.4 mm/rev). The analysis revealed that machining temperature increased with the employment of higher spindle speed and lower axial feed. Higher spindle speeds and axial feeds are desirable from the perspective of hole accuracy as they help produce holes within H9 diameter tolerance. Burr size was verified to be larger at the hole exit compared to the hole entry, with the size of the burr increasing with an increase in spindle speed and axial feed. The results show that the axial feed was the significant variable affecting chip size, followed by spindle speed. Higher axial feed (0.4 mm/rev) and spindle speed (4000 rev/min) helped improve the chip breakability, thus helping improve chip evacuation.

Effect of graphene on the mechanical and electrochemical properties of GLARE

This study explores the effect of different graphene contents on the mechanical behaviour, tensile and flexural properties, and the electrochemical performance of cross-layered glass-reinforced aluminium (GLARE) laminates. Results show that the mechanical properties of GLARE with different graphene contents are similar but not identical. The mass fraction of graphene (0 wt.%–1.0 wt.%) is calculated from the total mass of adhesive. As the graphene content increases (0 wt.%–1.0 wt.%), flexural strength peaks in the presence of 0.5 wt.% graphene, but tensile strength continues to increase. When the graphene mass ratio is 1.0 wt.%, the maximum tensile strength is 245.45 MPa. When the graphene mass ratio is 0.5 wt.%, interlaminar shear strength and flexural strength are 19.06 and 260.22 MPa, respectively, which correspond to different span–thickness ratios of 8/1 and 32/1. This graphene mass ratio indicates the best three-point flexural performance of graphene-reinforced GLARE. This study further explains the enhancement mechanism through fracture surface observation. Graphene with a mass ratio of 0.5 wt.% maximises the flexural strength whilst maintaining a strong GLARE electrochemical performance. At scanning speeds of 40, 80, and 100 mV/s, the specific capacitance values are 1.76, 2.47, and 2.88 F/g, respectively. According to quantum tunnelling theory, graphene can form a conductive network when it is dispersed in a resin matrix. This theory reveals the reason why 0.5 wt.% graphene platelet-modified GLARE has good electrochemical properties.

Effect of through-the-thickness position of aluminum wire mesh on the mechanical properties of GFRP/Al hybrid composites

Glass laminate aluminum reinforced epoxy (GLARE) mixes an extremely thin ply of aluminum wire mesh layers with epoxy strengthened with fibers to create a hybrid composite laminates. During this investigation, plain E-glass fiber/epoxy specimens in addition to specimens with epoxy laminates reinforced with both E-glass/fiber, and wire meshes of aluminum were created. Meshes made of aluminum wire were used to increase the toughness of the E-glass fiber/epoxy combination. Tensile, bending, and hardness tests were performed to see how inserting Al wire meshes through thickness of the specimen in place of glass fiber layers affected the material mechanical characteristics. According to the outcomes from results, an influence on strength, toughness, and ductility of laminates due to using Al wire mesh instead of glass fiber. The characteristics of the generated hybrid laminates were greatly influenced by the varying position and the orienting direction of the aluminum wire mesh ply. Inclusion of Al wire mesh in the outer layers significantly made deterioration in material tensile strength and bending strength. The tensile strain also bending strain, on the other hand, were improved by 16.95 percent and 117 percent, respectively.

Low velocity impact and axial loading response of hybrid fibre aluminium laminates

Low velocity impact and axial loading response of hybrid fibre aluminium laminates

A study of the manufacture of fiber aluminum laminates reinforced with glass and the effect of interfacial adhesive bonding on the impact’s behavior

Fibre metal laminates (FMLs) are worthy competitors for forefront flying essential because of their high express mechanical properties. They are suitable for a variety of applications, especially the exhaustion check. The concrete holding between the aluminium and FRP layers is the most critical factor in collecting these covers. This research looked at, two glass-fibre-reinforced aluminium (GLARE) overlays with different holding bonds were created. The effects of interfacial concrete hanging on the sway lead of these covers were then analyzed using drop weight sway based on tests the D7136 ASTM standard. It was discovered that the amount of damage is more critical in covers with poor interfacial performance grasp than in covers with a strong bond between the aluminium and glass layers. Similarly, FMLs with excellent grasp holding exhibit better resistance to low-speed sway, and their contrasting contact powers are approximately 25% higher than those of models with poor grasp holding. Similarly, most significant central redirections in covers with a strong grasp are approximately 30% lower than in FMLs with a weak grasp.

The experimental assessment of the various surface modifications on the tensile and fatigue behaviors of laminated aluminum/aramid fibers-epoxy composites

Fiber metal laminates (FMLs) are introduced as the kind of advanced hybrid composites consisting of the metals and composite layers, which the adhesion between those has an important role on the static and dynamic mechanical properties of these structures. To do so, the mechanical abrading, alkaline etching, forest products laboratory (FPL) and anodizing surface modification methods were performed on the 2024 aluminum for fabricating aramid fiber-reinforced aluminum laminate (ARALL). After that, by using tensile and fatigue tests as well as micro/macro-structural investigations, the static and dynamic mechanical properties of ARALL structures were studied. Based on the fatigue results at the stress level of 90%, the mechanical surface modification caused that the fatigue cycles reached to 2155 cycles, which was the highest fatigue cycles. Whereas in the stress level of 45%, the anodizing surface modification with the 34,420 fatigue cycles had the highest improvement. Given up the tensile results, the FPL and anodizing surface modified FMLs had the highest tensile strength, which were 317 and 319 MPa, respectively. The microstructural investigations showed that by using the various surface modification methods, the absorbing energy mechanisms of fatigue loadings by aramid fibers changed. Also, changes in the number and diameter of formed dimples in the aluminum skins were seen.

Predicting the response and perforation of fibre metal laminates subjected to projectile impact

PurposeThe purpose of this paper is to predict the response and perforation of fibre metal laminates (FMLs) subjected to impact by projectiles at different velocities.Design/methodology/approachA finite element (FE) model is constructed in which recently proposed dynamic constitutive models for fibre reinforced plastic (FRP) laminates and metals are used. Moreover, a recently developed dynamic cohesive element constitutive model is also used to simulate the debonding between FRP laminates and metal sheets. The FE model is first validated against the test data for glass laminate aluminum reinforced epoxy (GLARE) both under dropped object loading and ballistic impact, then used to perform a parametric study on the influence of projectile nose shape on the perforation of FMLs.FindingsIt is found that the present model predicts well the response and perforation of GLARE subjected to impact loading in terms of load-time history, load-displacement curve, residual velocity and failure pattern. It is also found that projectile nose shape has a considerable effect on the perforation of GLARE FMLs and that the ballistic limit is the highest for a flat-ended projectile whilst for a conical-nosed missile the resistance to perforation is the least.Originality/valueRecently developed constitutive models for FRPs and metals, together with cohesive element model which considers strain rate effect, are used in the FE model to predict the behaviour of FMLs struck by projectiles in a wider range of impact velocities; the present model is advantageous over such existing models as Johnson-Cook (JC) + Chang-Chang and JC (+BW) + MAT162 in terms of failure pattern though they produce similar results for residual velocity.

Low-velocity impact response of Kevlar/epoxy aluminum laminates

In this experimental study, the low-velocity impact behavior of aluminum–Kevlar laminates (ARALL) was investigated. ARALL composites were prepared in two different configurations as aluminum–Kevlar–aluminum (AKA) and Kevlar–aluminum–Kevlar (KAK). The aluminum alloy used in the preparation of the samples was supplied as 5754 series 2 mm thick plates. Kevlar fabrics were supplied in a weight of 300 g/m2 and in twill weave type. Laminated composites with Kevlar twill fabrics were made through hand lay-up followed by the compression-molding process. [K]4 composite laminates were obtained by curing Kevlar/epoxy laminates under 100°C and 7 bar pressure for 180 min. Then, samples of size 100 × 100 mm were cut from the plates with a water jet. The cut specimens were bound together with two-component adhesive. An Instron Dynatup 9250 HV impact test device was used for impact tests. The energy profiling method was used, which expresses the impact energy and the corresponding absorbed energy. The increasing impact energy was performed on the two configurations of ARALL composites until perforation occurred. The perforation threshold of AKA samples was approximately 70% higher than that of KAK samples.