Nickel Aluminum Research Articles

Tribological and corrosion characteristics of aluminium–copper alloys reinforced with alumina nickel aluminide cermet powder

Aluminium–Copper (Al-10Cu) alloys are widely used for structural components in the aviation sector. This study focuses on the synthesis and characterisation of Al-10Cu alloy reinforced with Al2O3-30(Ni-20Al) cermet particles to evaluate their microstructural, mechanical, tribological and corrosion properties. The Al-10Cu alloy was cast with varying percentages of cermet (2% and 4%) using a controlled casting process. Comprehensive microstructural analyses, including optical microscopy, SEM and EBSD, were performed to assess the grain structure and cermet distribution. The mechanical properties were evaluated through Vickers microhardness and tensile testing, while tribological performance was assessed using a Pin-on-Disc tribometer. Corrosion resistance was investigated through exfoliation and immersion corrosion tests. The results indicated significant improvements in microhardness and wear resistance with the addition of cermet particles, while the tensile strength showed a complex interplay between ductility and brittleness. Corrosion tests revealed enhanced resistance in cermet-reinforced specimens. This study demonstrates the potential of Al2O3-30(Ni-20Al) cermet as an effective reinforcement for aluminium alloys to achieve superior performance in structural applications.

Boosted photoelectrochemical activity of anodic titanium dioxide nanotubes by electrophoretically decorated nickel–aluminum layered double hydroxide

The splitting of water using photoelectrochemical (PEC) processes is a promising method for generating renewable hydrogen. However, the practical efficiency of converting solar energy to fuel in PEC systems remains limited by inadequate light absorption and the swift recombination of photogenerated charge carriers within the photoelectrode material. In our research, we present a photoanode that addresses these challenges. In this work, we report on the electrophoretic deposition of nickel–aluminum layered double hydroxide (NiAl-LDH) under different voltages onto anodic TiO2 nanotube arrays (TNTAs) as a convenient and economically viable fabrication route of versatile and durable photoanodes. PEC and optical spectroscopy examinations, including linear sweep voltammetry, electrochemical impedance spectroscopy, Mott-Schottky plots, and diffuse reflectance spectroscopy, reveal that NiAl-LDH/TNTAs composites exhibit a superior enhancement of visible light absorption and consequently water splitting photocurrent. We interpret the improvement of PEC water splitting performance of the NiAl-LDH/TNTAs with the band structure speculated by the binding energy and the flat-band potential and band-gap measurements which features this nanocomposite as a novel photocatalyst for future hydrogen energy applications.

Effect of iron doping on nickel aluminate photocatalytic activity towards the degradation of methylene blue under visible and UV light

The major issue that industries have is the degradation of organic dye in wastewater. In this study, we introduce an iron-doped spinel-type photocatalyst for dye degradation. Due to advantages like a lower band gap, and favorable magnetic characteristics, iron-doped nickel aluminate can be a viable catalyst for dye degradation. Nickel aluminate and iron-doped Nickel aluminate NiAl2-xFexO4 (x = 0.05, 0.1, 0.5, and 1.0) were synthesized by the sol-gel method using citric acid as a capping agent. The obtained samples were calcined at 800 °C for 4 h. The spinel was characterized using X-ray diffraction (XRD) which helped in the identification of the purity of the phase and the calculation of the average crystallite size. Fourier Transform Infrared (FT-IR) spectra confirmed the presence of iron in the octahedral site; (SEM-EDAX) Scanning Electron Microscopy facilitated the surface morphology and Energy-Dispersive X-ray analysis provided the elemental confirmation and UV-DRS techniques assisted in the calculation of the band gap using the Tauc plot method. Photocatalytic efficiency was investigated against the cationic dye Methylene blue under UV and Visible light. The results showed degradation of 94.25% under UV light and 83.51% under visible light in 90 min and 150 min respectively using iron-doped nickel aluminate.

Stress-Strain Behavior of Soft Soil Stabilized with Nickel Slag, Limestone, and Aluminum Hydroxide

Soil stabilization by combining several minerals is a form of material engineering aimed at increasing the bearing capacity of the soil to a higher level. The development of waste-based materials and the utilization of local potential are part of environmentally conscious construction. This study aims to analyses the mechanical behaviour of soil stabilized with several pozzolanic materials derived from nickel processing waste and limestone, which are local materials with very large deposits. ASTM standards were used in this study for both physical and mechanical testing. Unconfined compressive strength (UCS) tests were conducted to compare the mechanical behaviour of stabilized soil with that of natural soil. The test samples used were cylindrical with a diameter of 35 mm and a height of 70 mm. The binding materials consisted of nickel slag, aluminium hydroxide, and limestone, with the amount of each material based on the dry soil weight (γdry). The addition of lime in this study was varied at 2%, 4%, and 6%. The test results generally show that lime variations and curing time affect the increase in unconfined compressive strength (qu), with the highest value of 30.91 kg/cm² observed at 6% lime content after 28 days of curing.

Natural Seawater Impact on Crack Propagation and Fatigue Behavior of Welded Nickel Aluminum Bronze

ABSTRACTNickel aluminum bronze (NAB) is a complex alloy used extensively in the marine environment. Fatigue strength of NAB is reduced by welding and prior seawater corrosion. This study investigated the combined effect of corrosion and plasma welding on the fatigue behavior of NAB. Natural seawater corroded samples were used in tension‐tension cyclic loading tests to observe fatigue crack initiation, propagation, and failure. Fatigue cracks initiated from corrosion pits at the weld toe. Stress corrosion and fatigue cracks propagated along the path of β′ and κIII phases. A short crack growth model (SCGM) predicted fatigue strength using experimentally obtained material properties and corrosion pit dimensions. Model predictions were used to develop S‐N curves and were within 30% of experimental results. The SCGM produced accurate and reliable fatigue life results that could be applied by industry to aid in revalidation decision making and inspection scheduling.

An Investigation of Thermomechanical Behavior in Laser Hot Wire Directed Energy Deposition of NAB: Finite Element Analysis and Experimental Validation

Laser Hot Wire (LHW) Directed Energy Deposition (DED) Additive Manufacturing (AM) processes are capable of manufacturing parts with a high deposition rate. There is a growing research interest in replacing large cast Nickel Aluminum Bronze (NAB) components using LHW DED processes for maritime applications. Understanding thermomechanical behavior during LHW DED of NAB is a critical step towards the production of high-quality NAB parts with desired performance and properties. In this paper, finite element simulations are first used to predict the thermomechanical time histories during LHW DED of NAB test coupons with an increasing geometric complexity, including single-layer and multilayer depositions. Simulation results are experimentally validated through in situ measurements of temperatures at multiple locations in the substrate as well as displacement at the free end of the substrate during and immediately following the deposition process. The results in this paper demonstrate that the finite element predictions have good agreement with the experimental measurements of both temperature and distortion history. The maximum prediction error for temperature is 5% for single-layer samples and 6% for multilayer samples, while the distortion prediction error is about 12% for single-layer samples and less than 4% for multilayer samples. In addition, this study shows the effectiveness of including a stress relaxation temperature at 500 °C during FE modeling to allow for better prediction of the low cross-layer accumulation of distortion in multilayer deposition of NAB.

Feasibility of vanadium ion adsorption/desorption using nickel–aluminum complex hydroxides with different molar ratios

Herein, metal complex hydroxides containing nickel (Ni) and aluminum (Al) at different molar ratios (Ni:Al = 1:1 (NA11), 1:2 (NA12), 2:1 (NA21), 3:1 (NA31), and 4:1 (NA41)) were prepared. Scanning electron microscopy images, X-ray diffraction patterns, specific surface area, number of hydroxyl groups, and pHpzc were evaluated. Further, the adsorption capacity of vanadium ions was assessed, with NA21 showing a high potential to adsorb vanadium ions from the aqueous phase (177.5 mg/g). In addition, the effects of various factors, including pH, contact time, initial concentration, and temperature, on the adsorption of vanadium ions were demonstrated in this study using NA21. The optimal pH value for adsorbing vanadium ions was 5.0. Adsorption isotherms and kinetic data were fitted to a pseudo-second-order model (correlation coefficient: 0.958) and a Freundlich model (correlation coefficient: 0.930–0.982), respectively. This study elucidated that a part of the adsorption mechanism of vanadium was related to ion exchange and characteristics of NA21 surface. Moreover, NA21 showed capability to selectively adsorb vanadium ions from binary solution system containing chloride, nitrate, or sulfate ions. Vanadium ions adsorbed onto NA21 were more easily desorbed by a sodium hydroxide solution than a sodium sulfate solution. NA21 demonstrated consistent performance over at least three adsorption and desorption cycles under experimental conditions of this study. These findings provided valuable insights into the recovery of vanadium ions from aqueous media via adsorption/desorption treatment using NA21.

Corrosion of Copper, Cupronickel, Nickel Aluminium Bronze and Super-Duplex Stainless Steel Rotating Cylinder Electrodes in Seawater under Turbulent Flow Conditions

The corrosion of uncoated metals in a marine environment restricts the choice of suitable engineering metals and alloys. Anodic dissolution of metal and cathodic reduction of oxygen are important processes and formation of a surface oxide film can affect both electrode reactions. Charge transfer and mass transfer data can provide information on corrosion rate and mechanism. Several metals and alloys having a history of use in marine engineering are considered, including copper, two copper alloys (cupronickel and nickel aluminium bronze) plus a more recent addition to strong, corrosion resistant alloys (a super duplex stainless steel). The rotating cylinder electrode offers the benefits of a controlled, turbulent flow of electrolyte, facilitating controlled mass transfer in a compact cell geometry which is well-suited to bench-top operation. These features are illustrated using a variety of electrochemical techniques, including open-circuit potential vs time monitoring, linear sweep voltammetry, rotation speed step- or potential step current transients and linear polarisation resistance measurements. Seawater taken from Langstone Harbour, Hampshire, UK, was filtered, air-saturated, pH 8.0 and maintained at 25 °C. Dimensionless group correlations and graphical plots (using an analogous approach to the Koutecky-Levich equation for an RDE) enabled contributions of charge transfer-, mixed- and mass transfer- controlled data to be appreciated, allowing the Tafel slopes of electrode reactions, the diffusion coefficient of dissolved oxygen, the mass transfer coefficient for oxygen reduction and the mean corrosion rate to be estimated.

Superior cycle stability and enhanced pseudocapacitive performance of NiAl-LDH decorated carbon cloth for supercapacitor application

Pseudocapacitors, particularly using layered double hydroxides as cathode material, offers high-power capability and increased energy density, making them popular choices for energy storage devices. This study presents a unique porous structure featuring nickel aluminium layered double hydroxide (NiAl-LDH) deposited onto activated carbon cloth (CC) via a single-step electrochemical process. The NiAl-LDH@CC composite demonstrates exceptional pseudocapacitive capabilities with a specific capacitance of 5893.8 mF cm−2 at a current density of 0.7 mA cm−2 calculated from galvanostatic charge–discharge (GCD) responses. An asymmetric supercapacitor (ASC) is constructed using activated carbon cloth (CC) as anode and NiAl-LDH@CC as cathode. The as-built ASC device, with an operational voltage of 1.6 V, achieves a substantial specific capacitance of 310 mF cm−2 at a current density of 0.2 mA cm−2, along with a high energy density ∼51.67 μWh cm−2 and a power density ∼913.84 μW cm−2. An outstanding cycle stability is also observed with a retention rate of 90 % after 10000 continuous GCD cycles.

Effect of mixed metal oxide‐based catalysts for the removal of hydrophobic phthalates from water

AbstractContaminants of emerging concern (CECs) such as phthalic acid esters (PAEs) are ubiquitous, toxic and persistent in aquatic environments. Current study explored mixed metal oxide catalysts derived from magnesium aluminium (MAH), magnesium aluminium ruthenium (MAR‐H), magnesium aluminium nickel (MANH) hydroxides and copper aluminium hydroxides of ammonium (CAM‐Am) and sodium molybdate (CAM‐Na) to remove dibutyl phthalate (DBP) and di‐2‐ethyl hexyl phthalate (DEHP) from water. Powder X‐ray diffraction (XRD) studies of the catalysts before and after the treatment showed that their structures were stable and robust. During Fourier Transform Infrared (FTIR) studies, vibrational bands or peaks of ester and alkane functional groups of DBP and DEHP were observed at all the catalysts after treatment. Thermogravimetric analysis (TGA) confirmed phthalate adsorption at the five catalysts. Hydrolysis of DBP and DEHP was observed during treatment using CAM‐Am and CAM‐Na that was analysed and quantified using total organic carbon (TOC), high performance liquid chromatography (HPLC) and high‐resolution mass spectrometry (HRMS). From TOC analyses, optimal conditions of 500 mg L−1 catalyst dosage and 30 h treatment time were deduced for catalytic hydrolysis of DBP and DEHP. Present study illustrated that the catalysts MAH and MANH can adsorb PAEs while CAM‐Na can adsorb and hydrolyse them.

Synthesis of nanoscale spinel aluminates powder and studies of their optical and structural properties

In this research, Manganese aluminate (MA), Nickel aluminate (NA), and Zinc aluminate (ZA) nanocrystallites were synthesized using the combustion method at a temperature of 1173 K. This technique was selected for its effectiveness in producing nanocrystalline materials with high purity and precise compositional control. The synthesized nanocrystallites underwent extensive characterization to understand their structural and optical properties. Techniques such as UV–visible spectrophotometry (UV–vis), Fourier-transform infrared spectroscopy (FT-IR), and x-ray diffraction (XRD) were utilized to examine the impact of different cations (Mn2+, Ni2+, Zn2+) on the optical bandgap, binding energy, and crystallographic parameters of the materials. The optical bandgap values (Eg), determined using Tauc’s formula, were 4.121 eV for manganese aluminate, 3.819 eV for nickel aluminate, and 3.771 eV for zinc aluminate. FT-IR spectroscopy identified fundamental absorption peaks within the range of 450 to 750 cm−1, confirming the formation of aluminate spinel structures. XRD analysis confirmed the presence of a cubic spinel-type structure in all three prepared samples. The results revealed that the average crystallite sizes ranged from 23.890 nm to 45.100 nm, cell volumes varied between 521.47 Å3 and 548.68 Å3, lattice constants spanned from 8.258 Å to 8.049 Å, and inter-planar spacing ranged from 2.4268 nm to 2.4532 nm. These variations were observed as the cation transitioned from nickel to manganese passing through zinc element. Additionally, Rietveld refinements were performed to further analyze and refine the crystal structures based on XRD data. This comprehensive study aimed to elucidate the relationship between the synthesis conditions and the resultant properties of the nanocrystallites, providing insights into their potential applications in fields such as optoelectronics and photocatalysis.

Effects of heat treatment on the microstructure and corrosion behavior of manganese aluminum bronzes

Abstract Due to a much lower nickel content, manganese aluminum bronzes (MAB) are a cost-effective alternative to nickel aluminum bronzes (NAB). When the material is processed, different microstructures are observable in the material which have an impact on the corrosion resistance of MAB alloys. MAB samples were annealed at 900 °C and quenched in water. After that, annealing treatments at 600, 500, 400 and 300 °C for up to 24 h were performed and the samples were again quenched in water. Metallographic sections were prepared from all samples and potentiostatic corrosion tests at different potentials were performed in synthetic seawater. It was found that the sample annealed at 900 °C and quenched in water as well as those samples which underwent a second annealing treatment at low temperatures for shorter times exhibited a greater corrosion tendency than those undergoing a second annealing treatment at higher temperatures. X-ray diffraction measurements revealed that phase transformations and changes in grain size occurred during the annealing treatments. The increase in corrosion resistance as a result of annealing at higher temperatures is probably due to the strong intergrowth of the phases that are formed.

Influence of Laser Scanning Speed on Wear and Corrosion Resistance of Aluminum–Nickel Coating on Magnesium Alloy

Influence of Laser Scanning Speed on Wear and Corrosion Resistance of Aluminum–Nickel Coating on Magnesium Alloy

A comprehensive review on the analysis of adhesion strength of cold spray deposits

Cold spray (CS) is a new kind of coating that has many potential uses, including functionalizing surfaces, doing localized repairs, and mass production. Its fast deposition rate and diverse feedstocks have led to its growing popularity as an additive manufacturing method, which has been driven by improvements in lateral resolution. CS materials have several uses in the transportation industry, and some of the most frequent ones include nickel super-alloys, titanium alloys, copper, aluminum and metal-ceramic composites. Nevertheless, the mechanical properties depend upon number of parameters involved during spraying process. Therefore, there is an immediate need for researchers and businesses to understand the various parameters affecting the adhesion strength of CS deposits. The current research presents an analysis of the adhesion behavior of coatings that have been deposited by CS methodology.

A purine derivative for the modulation of the corrosion behavior of nickel aluminum bronze in seawater: a comprehensive and in-depth investigation on the corrosion inhibition mechanism

6-mercaptopurine (SMP), recognized for its biological activity, is investigated for its corrosion inhibition mechanism on nickel-aluminum bronze (NAB) in seawater, demonstrating a high efficiency of 99.6%. The physical adsorption of SMP on the NAB surface contributes to the multilayer structural arrangement of SMP. The Cu+-SMP complex is generated on the surface of NAB, which possesses a corrosion protection effect. SMP alters the semiconductor properties of corrosion product layer and reduces the carrier concentration. SMP can adsorb better on uncorroded NAB surfaces. This study holds significant importance in unraveling the mechanisms behind the corrosion behavior of NAB surfaces regulated by SMP.

Additively Manufactured Nickel Aluminum Bronze via Laser Powder Bed Fusion Shows Excellent Anticorrosion

Additively Manufactured Nickel Aluminum Bronze via Laser Powder Bed Fusion Shows Excellent Anticorrosion

Effect of Contact Time on Carbon Deposition and Catalytic Activity of Nickel Alumina Catalysts for Dry Reforming of Methane

AbstractDry reforming of methane (DRM) reaction is advantageous in producing syngas with a low H2/CO, relevant to many industries. Effect of contact time on catalytic activity and carbon deposition is studied for DRM using Ni−Al catalysts, along with the effect of metal loading, reaction temperature, and reactant partial pressure (CO2/CH4). Maximum CH4 conversion (58 %) and CO2 (59 %) were achieved at a higher contact time of 4.009 kg‐cat . h/kgCH4. A maximum of 46 % CH4 conversion was achieved at 1023 K with a contact time of 0.134 kg‐cat . h/kgCH4. Higher CH4 and CO2 conversion were achieved with an excellent H2 and CO yield due to the RWGS reaction with increased metal (Ni) loading (10–30 wt . %). When the reactant partial pressure (CO2) changed from 0.1–0.3, the CH4 conversion increased whereas CO2 conversion decreased. FESEM images revealed the formation of whisker‐like carbon fibers for all loadings. For the best syngas output and stability in a Ni‐based catalyst, a combination of a basic support (alumina) at a higher contact time (~4.009 kg‐cat . h/kgCH4) and a CO2/CH4 ratio of 1–1.5 at a moderate temperature of 873 K may provide best CO2 adsorption with minimal coking.

Synergistic improvement of erosion-corrosion resistance and mechanical properties of nickel aluminium bronze alloy by the addition of Cr

Synergistic improvement of erosion-corrosion resistance and mechanical properties of nickel aluminium bronze alloy by the addition of Cr

Atomic Layer Deposited Al1−xNixO: Low Contact Resistivity Hole‐Selective Contact for Crystalline Silicon Solar Cells

Transition metal oxide (TMO)/crystalline silicon (c‐Si) junction‐based heterostructure crystalline silicon solar cells have emerged as a promising alternative to traditional silicon solar cells. However, the power conversion efficiency of c‐Si solar cells utilizing a nickel oxide (NiOx) hole transport layer (HTL) still lags behind those employing a fully developed TMO layer. This disparity may be attributed, at least in part, to inefficient hole extraction. Atomic layer deposited (ALD) aluminum nickel oxide (Al1−xNixO) films, synthesized using bis(N,N′‐di‐t‐butylacetamidinato)nickel(II) (NiAMD) and trimethylaluminum (TMA) as precursors, along with deionized water as a co‐reactant, have been observed to improve the contact properties with p‐type silicon compared to NiOx. Al1−xNixO films with varying Al concentrations (0.25, 0.44, and 0.87) are examined for their contact performance on p‐Si, resulting in the lowest contact resistivity of 85 mΩ cm2. Optimized Al1−xNixO films exhibit superior hole extraction capability from p‐type silicon, leading to a remarkable conversion efficiency of 19.35% in the constructed p‐Si/Al1−xNixO/Ag solar cell. These findings underscore the advantages of utilizing ALD Al1−xNixO as a hole‐selective contact for crystalline p‐Si solar cells.

Unveiling the Ni2+ coordination sites effect of Ni-Al spinel catalysts for phenanthrene hydrogenation saturation

Nickel–aluminum (Ni–Al) spinel catalysts with distinct Ni/Al molar ratios were synthesized to construct Ni2+ coordination sites. Owing to the favorable distribution of Ni2+ coordination sites and the presence of suitable concentration of Ni2+ in octahedral sites, Ni/Al-0.725 catalyst achieved an 86.1 % average yield of perhydrophenanthrene, which was higher than that obtained with Ni/Al-0.25 (6.3 %). Characterization results indicated that Ni2+ of the Ni/Al-0.725 catalyst was present in octahedral sites and ∼ 40.4 % Ni2+ was reduced to Ni, whereas the active Ni metal of Ni/Al-0.25 catalyst mainly comprised Ni2+ occupying tetrahedral sites as precursors. Furthermore, the Ni/Al-0.725 catalyst exhibited the smallest Ni particle size (2.82 nm) and the largest Ni available surface (19.62 m2/gsample), which helped alleviate competitive adsorption among aromatic hydrocarbons. The Ni reduced by the spinel catalysts was in an electron-deficient state, which enhanced the adsorption of polycyclic aromatic hydrocarbons.