Al Plate Research Articles

Facile synthesis of hydrophilic layered double hydroxide film on aluminum plate

A facile synthesis method of a hydrophilic layered double hydroxide (LDH) film is required when the LDH film is used as an adsorbent, catalyst, and catalyst support in an aqueous solution. We successfully synthesized a hydrophilic film of a layered double hydroxide (LDH) on an aluminum (Al) plate at room temperature (20 °C) in a short time (120 min) by simply immersing it in a 25 mmol/L MgCl2 solution containing the optimal amount of NH3 water. The contact angle of the water was less than 5o on the obtained LDH surface of the Al plate. The surface morphology of the flower-like porous structure of the LDH film produced the hydrophilicity, because the water dropped on the porous LDH surface penetrated inside the void by capillary action. The obtained hydrophilic film on aluminum is expected to be used for various practical applications in an aqueous solution.

Effect of the static shoulder on microstructural, textural, and mechanical characteristics during friction stir welding of Al6061

In the present investigation, a novel static shoulder friction stir welding (SSFSW) tool has been designed and fabricated. The designed tool works both as rotating shoulder FSW (RS-FSW) and SSFSW. To evaluate the effectiveness of the developed tool, Al6061 plates have been subjected to both RS-FSW and SSFSW using the indigenously developed tool. The microstructure evolution, axial force, texture development, and mechanical properties were evaluated and compared for both RS-FSW and SSFSW. Adequate heat generation in SSFSW resulted in a homogeneous structure at the stir zone. Electron back scattered diffraction analysis demonstrated the presence of red-colored regions along the grain boundaries indicative of more dislocation density. These regions acted as preferable sites for precipitate (Mg2Si) accumulation, which greatly affected the mechanical properties of the joint. SSFSW joints contained a strong {111} texture of R-cube and S component with a maximum intensity of 6.85, while RS-FSW joints contained A and A* components with a maximum intensity of 4.85. The hardness plots showed a wide lower hardness region in RS-FSW with a maximum hardness of 101HV and 110HV (SSFSW). During the tensile test, both the joints failed in the lower hardness region after achieving 88% (SSFSW) and 75% (RS-FSW) strength of base material.

An innovative data-driven probabilistic approach for damage detection in Electromechanical Impedance Technique

The electromechanical impedance method (EMI) has shown its damage detection capacity under hazardous environments. Moreover, it is cost-effective, because it involves a bonded piezoelectric transducer (PZT). But the daunting task in the EMI method is the selection of robust and effective damage index, frequency ranges, and combining the information for damage quantification. In this paper, an innovative standard deviation approach is used for the selection of effective frequency ranges. The novice nature of frequency range selection is based on the difference between healthy and damaged state data. Further, a data fusion technique is introduced for damage detection and classification using analytical and experimental data in this effective frequency range. This paper presents four samples of metal and composite with different damage scenarios to demonstrate the applicability of the method. The paper investigates damage in thin aluminium (Al) plate with holes using the EMI method. Further, simulated mass damage and impact damage study to the glass fiber reinforced polymer (GFRP) composite plate. A combined C-index statistical data-driven damage matrices are calculated and further compared with the RMSD index approach. The method looks suitable for identifying the damage location and damage severity simultaneously and is more effective for the less severe damage cases.

Preparation and bonding mechanisms of polymer/metal hybrid composite by nano molding technology

Abstract With the development of nano molding technology (NMT), the polymer/metal hybrid (PMH) composites have made great progress in industries like automobile, aircraft, and boat. The bonding structure and bonding strength are the key factors ruling the application of PMH. In this work, the PMH containing polyphenylene sulfide (PPS) and Al alloy was prepared by NMT, and the surface treating of Al alloy and the bonding mechanism of PMH has been studied. The results reveal that the bonding strength between metal and polymer shows dependence on the pore structure of the metal surface, which could be controlled by changing the anodizing voltage and time. The PMH in which the Al plate was anodized at 15 V for 6 h achieves the best bonding strength of 1,543 N. The morphological analysis reveals that there forms an anchor and bolt structure in the interface of PPS and Al plate, which bonds the polymer and metal tightly. In addition, the chemical interaction between PPS and Al was confirmed by attenuated total reflection (ATR) infrared spectroscopy, which indicates that both physical and chemical effects contribute to the bonding strength of the PMH. This PMH has great potential of being used as alternative to traditional pure metal components, especially the packing materials of automobiles, electronic products, and furniture.

Thermal resonance model for micro-oscillators in the vicinity of a geometric boundary

This study explores the damping behavior of micro-oscillators within the transitional flow regime between molecular flow and viscous flow, including the presence of a neighboring geometric boundary. The damping is described by a model based on standing thermal waves (STW), which form a thermal resonance depending on the pressure and on the gap width to the boundary. This concept was first introduced in a previous paper for a nitrogen atmosphere and is now examined for seven further gases (He, Ne, Ar, Kr, CO2, N2O, SF6). The distance between the micro-oscillator and the confining geometry, given by an Al plate, is in the range of 150 µm to 3500 µm. Fitting the thermal wave model to the experimental data shows very good agreement and explains the convex region for the measured quality factor Q in the transition from the molecular to the viscous flow regime. The evaluation of the thermal resonance model shows a strong correlation between the ambient pressure at which thermal resonance occurs and the thermal properties of the gas (i.e. thermal diffusivity a and adiabatic index κ) including the gap width h which is in agreement with the proposed theory. This opens up the possibility of using micro-oscillators to measure the thermal properties of gases in a very precise way, comparable to the thermal wave resonator cavity principle, but with a much simpler and smaller setup.

Hypervelocity Impact Detection and Location for Stiffened Structures Using a Probabilistic Hyperbola Method.

Hyper-velocity impact (HVI) caused by a collision between orbital debris and spacecraft exists widely in outer space, and it poses a threat to spacecraft. This paper proposes a probabilistic hyperbola method based on Lamb waves analysis to detect and locate the impact in stiffened aluminum (Al) plates. A hybrid model using finite element analysis (FEA) and smoothed particle hydrodynamics (SPH) was developed to gain an insight into characteristics of HVI-induced acoustic emission (AE) and shock wave propagation. In addition, an experimental validation was carried out with a two-stage light gas gun, giving an aluminum projectile a velocity of several kilometers per second. Then a quantitative agreement is obtained between numerical and experimental results, demonstrating the correctness of the hybrid model and facilitating the explanation of received AE signals in experiments. Signal analysis shows that the shock wave quickly converts to a Lamb wave as it propagates from the HVI spot, and the zeroth-order symmetric wave mode (S0) dominates wave signal energy. The S0 wave is dispersive and shows a wide frequency range, with dominant magnitudes below 500 kHz. Finally, the HVI experiment results obtained with a light gas gun showed that the average location error could be less than 1 cm with only four sensors for a 1-square-meter stiffened metal plate.

Formation of Bright White Plasma Electrolytic Oxidation Films with a Uniform Maze-Like Structure by Anodizing Aluminum in Ammonium Tetraborate Solutions

Bright white plasma electrolytic oxidation (PEO) films with uniform maze-like structures were obtained by anodizing Al in an ammonium tetraborate solution. High-purity Al plates were galvanostatically anodized in 0.3–2.4 M ammonium tetraborate solutions at 303–343 K and 10–100 Am−2. A PEO film consisting of an outer porous layer consisting of amorphous alumina and crystalline alumina with α-and γ-phases and an inner amorphous barrier alumina layer was obtained on the Al surface. An extremely uneven PEO film with various pore sizes and many cracks was formed in a 0.3 M ammonium tetraborate solution, whereas a relatively uniform porous PEO film with similar pore sizes was obtained in 0.9–2.4 M solutions. This difference in the PEO film morphology was due to the plasma generation behavior while anodizing. The lightness of the PEO film increased with increasing anodizing time and PEO film thickness; thus, a bright white PEO film measuring 87.5 in lightness (L*) was formed on the Al surface. The water wettability of the PEO film exhibited weak hydrophilicity. Moreover, a superhydrophobic PEO film with a contact angle of 154° was easily fabricated by self-assembled monolayer modification. Similar bright white PEO coatings were successfully fabricated on various industrial alloys.

Prediction of the strength of aged Al-Cu alloys with non-hybrid and hybrid {1 0 0}Al plates

The effect of precipitate hybridization on macroscopic strengthening in aluminum alloys is investigated on the example of Al-Cu alloy using multiscale approach combining molecular dynamics (MD), continuum modeling and discrete dislocation dynamics (DDD). Non-hybrid and hybrid {100}Al plates are considered to involve θ′-phase and θ′-phase in the core and Guinier-Preston zone (GP-like) structure along the broad interfaces, respectively. MD simulations evidence a complex dislocation-precipitate interaction mechanism involving bypassing of both hybrid and non-hybrid {100}Al plates by dislocations at early deformation stages and their shearing by the following dislocations. MD results are used to calibrate a continuum model of dislocation-precipitate interactions in 2D DDD. The shear strength of alloy with hybrid precipitates is found to be 20% higher than that for non-hybrid plates at the same Cu content exceeding 2 wt%.

Effect of micro-cracks on mechanical and damping properties of double-layered Al/Al plate

To investigate the influence of micro-cracks (including formation and growing) on mechanical and damping capacity, the grooved (with two dimensions) and non-grooved Al plates were subjected to cold roll bonding (CRB). Microscopic morphology, tensile and damping test of the experimental materials were investigated. Due to uneven stress distribution, the edges of grooves were heavily inclined in the normal direction (ND), and the grooves were changed into micro-cracks with the sizes of a few to a dozen microns. Mechanical properties of the Al sheet with micro-cracks were decreased, which further lowered with micro-cracks growing. There were two internal friction peaks for the Al sheet with micro-cracks, which mainly attributed to the stronger local stress and local plastic deformation around the micro-cracks.

Investigation into the Intermetallic Layers in Ti/Al Multi-Layer Composites Produced via Accumulative Rolling and Sintering

For anti-penetration applications, multilayer composites combining hard brittle elements confronting penetrators and ductile materials at the back are attractive. Because of the weak connection between the ductile and hard brittle layers, these composites usually lose their anti-penetration capability when the hard, brittle layer falls apart. In the present work, attempts to produce in-situ hard, brittle layers were carried out through accumulative roll bonding (ARB) and post-sintering. It is found that an intermetallic interlayer of TiAl3 can be produced between Ti and Al plates with full integrity under a proper sintering condition. The diffusion mechanism between Ti and Al layers was analyzed via microstructural characterization. It implies that Al serves as the primary diffusion phase between Ti and Al plates. This work may shed light on the development of high-performance anti-penetration multi-layer composites.

Weldability Window for High-Velocity Impact Welding of Al and Ti Plates Obtained by Numerical Simulation

In this study, the process of high-velocity impact welding of commercially pure Al and Ti plates was simulated using smoothed particle hydrodynamics (SPH) method. The paper aimed to determine by numerical simulation the range of collision parameters suitable for Al and Ti welding, and to compare the results obtained with the known semi-empirical models used to construct the "weldability window". For this, a set of simulations with different collision point velocity and collision angle was carried out. From the data obtained, it follows that SPH simulation reproduces well the shape of the interface, typical for high-velocity impact welding, and provides better understanding of material flow and related phenomena. This method allows one to select the collision parameters that are optimal for a high-quality joint.

Effect of pulsed laser and laser-arc hybrid on aluminum/steel riveting-welding hybrid bonding technology

The microstructure and properties of aluminum (Al)-steel dissimilar metal riveting-welding joints obtained by the pulse laser and laser-arc hybrid welding methods were investigated. For simple laser beam riveting-welding Al and steel joint, the maximum tensile shear load of the joints was 6.3 kN, as the average laser beam power was about 438 W. The microstructure of the fusion zone (FZ) of the joint was twin martensite (TM), and there were small cracks in the weld. The Al elements were uniformly distributed in a vortex-shaped in the mixed region consisting of QP980 steel, 6061 Al alloy, and Q460 rivet, and the intermetallic compounds (IMCs) at the Al-steel interface had FeAl, Fe2Al5, and FeAl3. For the laser-arc hybrid riveting-welding joint, the maximum tensile shear load of the joint with an average laser power of 160 W and a tungsten inert gas (TIG) current 100 A was 7.25 kN. Lath martensite (LM), ferrite (F), and retained austenite (RA) were generated in the FZ of the joint, and the Al element aggregates in bulk and sporadically distributed in the mixed zone consisting of the steel plate, Al plate, and rivets. Furthermore, the differentiated distribution mechanism of Al element in riveting-welding hybrid joints was discussed in this paper.

Facile Synthesis of Fluorinated Polysilazanes and Their Durable Icephobicity on Rough Al Surfaces.

Superhydrophobic Al surfaces with excellent durability and anti-icing properties were fabricated by coating dual-scale rough Al substrates with fluorinated polysilazane (FPSZ). Flat Al plates were etched using an acidic solution, followed by immersion in boiling water to generate hierarchical micro-nano structures on their surfaces. The FPSZ coatings were synthesized by grafting 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (FAS-17), a fluoroalkyl silane), onto methylpolysilazane, an organopolysilazane (OPSZ) backbone. The high water contact angle (175°) and low sliding angle (1.6°) of the FPSZ-coated sample with an FAS-17 content of 17.3 wt% promoted the efficient removal of a frozen ice column with a low ice adhesion strength of 78 kPa at −20.0 °C (70% relative humidity), which was 4.3 times smaller than that of an OPSZ-coated surface. The FPSZ-coated Al surface suppressed ice nucleation, leading to a decrease in ice nucleation temperature from −19.5 to −21.9 °C and a delay in freezing time from 334 to 4914 s at −19.0 °C compared with the OPSZ-coated Al surface. Moreover, after 40 icing–melting cycles the freezing temperature of a water droplet on the FPSZ-coated Al surface remained unchanged, whereas that on the FAS-17-coated Al surface increased from −22.3 to −20.7 °C. Therefore, the durability of the polymeric FPSZ coating was superior to that of the FAS-17 monolayer coating.

Fabrication of zinc-aluminum layer double hydroxide thin films and their anionic adsorption performance

Layered double hydroxides (LDHs) are also known as hydrotalcite-like compounds or anionic clays. In this work, ZnAl-LDH films were prepared on aluminium (Al) plates by a hydrothermal technique using zinc nitrate solution as the precursors. ZnAl-LDHs films were characterized by SEM, EDX, XRD and FT-IR. The SEM analysis revealed that the ZnAl-LDH films with hierarchical nanoarchitectures on the surface of Al plates. EDX mapping and elemental analysis also showed that Zn, Al, and O dispersed uniformly on the aluminium substrates. XRD results were used to confirm the presence of ZnAl-LDH films as they appeared purely with the typical (003) and (006) peaks of LDH diffraction. The characteristic bands of bending vibrations due to the intercalating water, stretching vibration due to the overlapping signal of carbonate anion and nitrate anion were measured by FT-IR spectroscopy. The brucite structure also exhibited the OH-stretching vibration as well as the ZnO lattice vibration in the spectra. These ZnAl-LDH forms were evaluated for their removal performance against orange II dye solutions.

Studies on mechanical and morphological of TIG welded aluminum alloy

An automated TIG welding system was employed to increase the welding strength and weld quality of pure Aluminum (Al) plate in terms of bead width and depth of penetration. The control parameters during the welding process are the most critical factors, such as welding speed and arc length. TIG welding is a procedure that involves maintaining an electric arc between a non-consumable tungsten electrode and the weldable component. Due to its strong corrosion resistance, AA5059- aluminium alloy is the most often used in the ship industry sectors as a hull material.

Roll-Bonding of Mg and Al Plates Assisted by Cold Spraying Micro Particle Interlayer

Roll-Bonding of Mg and Al Plates Assisted by Cold Spraying Micro Particle Interlayer

Design, preparation and performance evaluation of core unit in multispectral camouflage coating

The constantly increasing progresses of multi-spectrum detection technology, as well as the diversification of the natural background, have necessitated the need to devise new camouflage coating approaches. The conventional camouflage coating technology that is limited to the visible light band is far from being suitable for the combinational detection of visible, infrared, and hyperspectral light. Along these lines, in this work, a novel concept idea is proposed to fabricate multispectral camouflage coatings based on the design of the core unit. The underlying idea is to employ various coatings in order to address the broadband reflectivity characteristics of the natural background in a wide frequency range, which cannot be attained by employing a single-spectrum coating material. Moreover, the combined design and application of single-spectrum coatings could be in the unit suitable range to be consistent with the characteristics of the natural background of visible light/infrared/hyperspectral. The core unit design elements incorporate the characteristics of single-spectrum coating materials, the employed ratio of various single-spectrum coatings, as well as the camouflage patterns and camouflage basic unit sizes. Besides, the performance of the final multispectral camouflage coatings is evaluated by the color difference, the hyperspectral reflectivity curves, the master saliency maps, and the edge characteristics. Based on the hybrid background of both vegetation and desert, various single spectral coatings including visible light coatings (green and brown) with suitable hyperspectral characteristics and infrared coatings with different emissivity in the waveband of 8–14 μm were selected for the production of multispectral camouflage patterns in a fixed-size (1 × 1 m2) substrate. More specifically, the camouflage patterns possess rectangular and hexagonal shapes with a basic size of 5 cm in diameter. Finally, the as-prepared multispectral camouflage coatings were measured in different airspace conditions (12–42 m). Compared with both the pure Al plate and the multispectral camouflage coating with rectangular patterns (M2), the proposed multi-spectral camouflage coating with hexagonal patterns (M1) exhibits optimal compatible stealth performance in the coupling bands of visible light and infrared wavebands.

Welding and Riveting Hybrid Bonding of 6061 Al and Carbon Fiber Reinforced Composites.

Welding and riveting hybrid bonding technology was applied to join 6061 aluminum alloy and carbon fiber reinforced plastics (CFRP). The laser-arc hybrid welding process and stepped rivets were used in the experiments to reduce the impact of the poor heat resistance of composites. The effect of hybrid welding arc current on the formation and mechanical properties of 6061 Al/CFRP joints was studied. Tensile shear load up to 4.65 kN was achieved by adjusting process parameters. The welding process and mode of the fracture were analyzed. The hybrid bonded joint obtained consisted of two parts: a welded joint of Al plate and Al rivet, and a bonded interface between Al plate and CFRP plate. The mechanical properties of the hybrid joint were mainly determined by the Al plate/Al rivet welded joint. The results of the study show that there are three interfacial bonding mechanisms between aluminum and CFRP. In addition to mechanical bonding between the Al plate and CFRP plate, there were also metallurgical bonding of Al-Mg intermetallic compounds with resin matrix and chemical reactions of aluminum with resin and carbon fibers at the interface, which could improve the mechanical properties of the joints.

Optimizing high harmonic generation in hollow-core gas cell considering variation of gas density

We have developed a coherent and compact extreme-ultraviolet light source based on phase-matched high harmonic generation by using a hollow-core gas cell that can be easily aligned and maintain long stability. The gas cell consists of three bodies to minimize gas leakage and maintain stable vacuum. The photon flux was calculated considering the dependence of the gas number density and the pressure on the radii of the hollow core and the hole in the Al plates on both sides of the gas cell, which showed good coincidence with the experimental values.The photon flux is 2 × 1010 photons s−1 near 13.5 nm (91.5 eV) within 10 nm bandwidth. Also, the compact extreme-ultraviolet light source is found to operate stably for hours, which is suitable for practical applications such as metrology and inspection for extreme-ultraviolet mask, spectroscopy, holography, microscopy, etc.

Efficient deposition of indium by cementation from chloride solutions

The possibility and the main characteristics of cementation applied for indium recovery from aqueous chloride and sulphate solutions were considered theoretically and examined experimentally. Aluminium and zinc, in the forms of plates and powders were examined as reducing agents. It was found that indium can be cemented on Al or Zn surfaces best in chloride solutions. Zinc plate proved to be inefficient, however Zn powder performed well. In the case of aluminium, both the plate and the powder worked well, and virtually complete recoveries of indium could be achieved within 10–60 min - depending on the pH and temperature of the solutions. The produced sponge can be detached easily from the Al plate and efficiently melted under protective atmosphere, vacuum or salt flux. The purity of the produced sponges can be generally above 99.9%, and the cementation on Al plate produces the purest indium.