Zn Ni Alloy Research Articles

Study on the tribocorrosion behavior of Cu–Ni–Zn alloy in deep-sea environment by in-situ electrochemical method

The tribocorrosion behavior of Cu–Ni–Zn alloy was investigated by using in-situ electrochemical controlled tribocorrosion technology in deep sea. The results showed that the tribocorrosion rate increased with hydrostatic pressure (i.e., seawater depth) at a rate of 1.05 × 10−5 mm3·N−1·m−1·MPa−1. Hydrostatic pressure had significant influence on corrosion and tribocorrosion behaviors. At higher hydrostatic pressure, the cathodic reaction was accelerated and then the anodic dissolution process retarded. The passive film at higher hydrostatic pressure exhibited a larger amount of insoluble Cu(Ⅰ) species (CuCl and Cu2O). On the other hand, with the increasing hydrostatic pressure, the adhesive wear decreased, while the abrasive and delamination wear aggravated. The increment in mechanical wear with hydrostatic pressure was determining factor for the tribocorrosion of Cu–Ni–Zn alloy in deep-sea.

Dynamic reconstruction of Ni-Zn alloy solid-electrolyte interface for highly stable Zn anode

Dynamic reconstruction of Ni-Zn alloy solid-electrolyte interface for highly stable Zn anode

Physico-Chemical Properties of Zn-Ni Alloy from an Alkaline Sulphate Bath Containing Triethanolamine and Mercaptopyridine

The composition, properties and morphology of electrodeposited Zn-Ni alloy from an alkaline sulphate bath containing triethanolamine (TEA) and mercaptopyridine (MPY) have been investigated. A bath solution containing 3.5% wt. Ni content produced an alloy deposit with 12.5% wt. Ni (more noble metal) indicating preferential deposition of nickel (i.e. Regular co-deposition process). With increase in current density and the concentration of TEA, the percentage of nickel in the alloy deposit decreased. An increase in temperature, thickness and the concentration of MPY increases the percentage of nickel (more noble) in the Zn-Ni alloy deposit. CCE was decreased with current density, increased with temperature and stirring of the bath solution. Static potentials of Zn-Ni alloy were less noble to nickel and more noble to zinc. Hardness of the alloy increased with an increase in %Ni in an alloy. Fine grained deposits were observed morphologically.

Bimetallic Ni-Zn@OMC catalyst for selective hydrogenation of levulinic acid to γ-valerolactone in water

Hydrogenation of levulinic acid to γ-valerolactone is one of the important reactions for conversion of biomass into renewable fuels and chemicals. Ni-Zn non-noble bimetallic catalysts supported on ordered mesoporous carbon (Ni-Zn@OMC) were prepared by one-pot solvent evaporation induced self-assembly (EISA) method and used for hydrogenation of levulinic acid to γ-valerolactone (GVL) in water. A GVL yield of 93% was obtained over bimetallic Ni1-Zn1@OMC catalyst at 180 °C in 90 min reaction time, with a turnover frequency (TOF) of 686.4 h−1. Compared with Ni@OMC, the incorporation of Zn metal leads to the formation of Ni-Zn alloy and high dispersion of Ni particle on the catalyst surface. NiO sites on the catalysts lowered competitive adsorption between H2 and levulinic acid on Ni0 sites, as well as the Ni-Zn alloy is beneficial to the activation of carbonyl group in levulinic acid, and they synergistically promote the hydrogenation of levulinic acid to 4-hydroxyvaleric acid (4-HVA). Zn content in the catalyst influences both the activity of Lewis acid sites and the ratio of Lewis acid to Brønsted acid sites, and the active sites of Niδ–Znδ+ can facilitates the weakening and cleavage of C-O in 4-HVA, both of them are beneficial to the dehydration of 4-HVA to GVL.

Effect of Zn on performance of Ni/SiO2 for hydrodeoxygenation of anisole

Herein, SiO2 supported metallic Ni (Ni/SiO2) and bimetallic Ni-Zn (NixZn/SiO2) (x represents the Ni/Zn atomic ratio) catalysts were prepared by the incipient wetness impregnation method and their activities were tested in vapor phase hydrodeoxygenation (HDO) of anisole under 0.1 MPa. The characterization results show that Ni-Zn alloy forms in NixZn/SiO2 after reduction at 550 °C, and a suitable Ni/Zn atomic ratio (30) leads to smaller alloy particle size and consequently more H2 adsorption amount than others. In the HDO reaction, the formation of Ni-Zn alloy facilitates the direct deoxygenation pathway and suppresses CO methanation and C−C bond hydrogenolysis, which is ascribed to the isolation effect of the Ni atoms by the oxophilic Zn ones. Ni30Zn/SiO2 gives not only higher anisole conversion but also higher selectivity to benzene than Ni/SiO2. Therefore, the introduction of a suitable amount of oxophilic Zn in Ni/SiO2 promotes the HDO of anisole to benzene. Finally, we propose that the Ni30Zn/SiO2 deactivation is related to the oxidation of Ni-Zn alloy and carbon deposition on the catalyst surface.

Efficient conversion of 5-hydroxymethylfurfural to 2,5-dimethylfuran by the rational design of NiZn catalysts

The transformation of biomass to liquid fuels and chemicals is of great interests. Herein, a series of reduced NiZn-CT (CT represents calcination temperature) catalysts with flower-like morphology and uniform particle sizes were prepared by co-precipitation method and used for hydrogenolysis of 5-hydroxymethylfural (HMF) to 2,5-dimethyfuran (DMF). The characterizations evidenced the formation of NiZn alloy phase in the catalysts through the strong metal-support interaction (SMSI), which had high C-O hydrogenolysis ability. The synergy of hydrogenation and C-O hydrogenolysis is essential for HMF to DMF, and we surprisingly found that this synergistic effect can be achieved just by controlling calcination temperature to regulated SMSI between Ni and ZnO. By this way, 99% DMF yield was gained at 180 °C for 4 h under 2 MPa H2 over reduced NiZn-450 catalyst. More importantly, the active centers of this Ni/ZnO catalyst exhibited outstanding stability. There was no significant decrease in activity after reusing 9 times. The current research provided an easy-made catalytic system for HMF hydrogenolysis.

Synergistic Effect of Brightener and Solution Temperature on the Electrodeposition Behavior of Zn–Ni Alloy from Alkaline Zincate Solution

Synergistic Effect of Brightener and Solution Temperature on the Electrodeposition Behavior of Zn–Ni Alloy from Alkaline Zincate Solution

In Situ Reconstructed Zn doped Fex Ni(1- x ) OOH Catalyst for Efficient and Ultrastable Oxygen Evolution Reaction at High Current Densities.

Developing FeOOH as a robust electrocatalyst for high output oxygen evolution reaction (OER) remains challenging due to its low conductivity and dissolvability in alkaline conditions. Herein, it is demonstrated that the robust and high output Zn doped NiOOH-FeOOH (Zn-Fex Ni(1-x) )OOH catalyst can be derived by electro-oxidation-induced reconstruction from the pre-electrocatalyst of Zn modified Ni metal/FeOOH film supported by nickel foam (NF). In situ Raman and ex situ characterizations elucidate that the pre-electrocatalyst undergoes dynamic reconstruction occurring on both the catalyst surface and underneath metal support during the OER process. That involves the Fe dissolution-redeposition and the merge of Zn doped FeOOH with in situ generated NiOOH from NF support and NiZn alloy nanoparticles. Benefiting from the Zn doping and the covalence interaction of FeOOH-NiOOH, the reconstructed electrode shows superior corrosion resistance, and enhanced catalytic activity as well as bonding force at the catalyst-support interface. Together with the feature of superaerophobic surface, the reconstructed electrode only requires an overpotential of 330mV at a high-current-density of 1000mA cm-2 and maintains 97% of its initial activity after 1000h. This work provides an in-depth understanding of electrocatalyst reconstruction during the OER process, which facilitates the design of high-performance OER catalysts.

Zn–Ni Alloy Plating with Trivalent Chromate: Effects of NaF Additive Concentration and Treatment Time on Film Color, Thickness, and Electrochemical Properties

Zn–Ni alloy plating is widely applied in manufacturing of automobile and construction material components because it provides better corrosion resistance and wear resistance than Zn plating. Furthermore, chromate coating treatment is gaining attention with respect to improving the corrosion resistance of Zn–Ni alloys. In this study, we investigated the effects of NaF additive concentration and treatment time on trivalent chromate coating, which has been developed as an alternative to hexavalent chromate coating. The chromate post-treatment solution used in this study comprises Cr(NO3)3·9H2O (360 g/L), CoSO4·7H2O (40 g/L), and HNO3 (35 mL/L), to which NaF is added in the concentration range of 0–30 g/L. The as-formed coating films at 1.6 pH and 60 °C treatment temperature for deposition times ranging from 30 to 120 s demonstrated a decreasing corrosion rate as the NaF concentration increased. The electrochemical and morphological analyses inferred that NaF acted as a catalyst, enhancing the rate of film formation. Furthermore, the film thickness increased with the treatment time, and the film color changed in the order of yellow, purple, and green.

Effect of Solution Temperature on Electrodeposition Behavior of Zn–Ni Alloy from Alkaline Zincate Solution

Effect of Solution Temperature on Electrodeposition Behavior of Zn–Ni Alloy from Alkaline Zincate Solution

(Digital Presentation) Znni Electroplating from an Ethylene Glycol Based Non-Aqueous Electrolyte for Corrosion Protection

ZnNi alloys containing Ni in the 15 - 25 % wt. range have recently attracted the attention of researchers due to their interesting corrosion properties [1]. These materials, when deposited in the form of thin films, find application in a large number of industrial fields: oil and gas, automotive and constructions. ZnNi is normally electrodeposited from aqueous solutions, specifically alkaline cyanide-free or acidic chloride baths. In these electrolytes, plating takes place following a typical anomalous mechanism where the less noble metal (zinc) deposits preferentially [2].Even though ZnNi plating from water based solution is already implemented at the industrial scale, alternative deposition approaches have been developed in the last few years to further improve ZnNi plating performances. In particular, the use of non-aqueous electrolytes has been investigated by virtue of their significant advantages over water based solutions: wider electrochemical windows, reduced side reactions and low vapor pressure. ZnNi electrodeposition has been attempted from a great variety of such novel baths, mainly including II and III generation ionic liquids [3, 4].The present work investigates the use of non-aqueous ethylene glycol based electrolytes for the deposition of ZnNi alloys containing Ni in the 15 - 25 % wt. range. The use of ethylene glycol as solvent introduces many advantages with respect to aqueous solutions: low oxygen contamination, high deposits purity and no pH dependance [5]. ZnNi codeposition from ethylene glycol baths containing ZnCl2 and NiCl2 was studied employing cyclic voltammetry and thin layers were deposited under potentiostatic control. Deposition potential was varied and its influence on final composition and morphology was determined. Compositional data evidenced the occurrence of a potential dependent anomalous codeposition mechanism analogous to the one reported in water based electrolytes. Addition of an additive (NH4Cl) to enhance surface morphology was attempted as well [4]. Phase composition was investigated using XRD and the results obtained demonstrated the presence of a metastable γ-ZnNi phase, which has already been observed in the case of ZnNi plated from alkaline aqueous solutions [6]. Finally, corrosion behavior of the ZnNi layers obtained from ethylene glycol was assessed and compared with equivalent coatings deposited from commercial ZnNi aqueous solutions.[1] M. Gavrila et al., Surf. Coat. Technol. 123 (2-3), 164-172 (2000)[2] G. Roventi et al., J. Appl. Electrochem. 30 (2), 173-179 (2000)[3] K. K. Maniam et al., Appl. Sci. 10, 5321 (2020)[4] S. Fashu et al., Trans. Nonferrous Met. Soc. China 25 (6), 2054-2064 (2015)[5] G. Panzeri et al., Electrochim. Acta 271 (1), 576-581 (2018)[6] S. Ieffa et al., Trans. Inst. Met. Finish. 94, 321-324 (2014)

PANi/PPy and PANi Films on ZnNi Alloy Coated Carbon Steel; Electrochemical Syntheses and Corrosion Performances

Zinc–nickel alloy coating (ZnNi) was successfully deposited on carbon steel (CS) applying current density of 47 mAcm-2 with galvanostatic technique. The ZnNi alloy coating image showed that CS metal surface was plated with a blue-grey homogeneous layer. Polyaniline film (PANI) film was synthesized with cyclic voltammetry technique from 0.10 M aniline containing 0.20 M sodium oxalate solution on ZnNi coated carbon steel (CS/ZnNi) electrode surface. And then the synthesis of top PPy film was achieved in pyrrole monomer containing acetonitrile + tetrabutyl ammonium perchlorate medium successfully. After the top PPy synthesis, it was observed that both the PANi homopolymer film and the ZnNi coating continued to exist on the CS surface. The corrosion behaviors of uncoated and coated electrodes were investigated in 3.5% NaCl solution. For this aim, the anodic polarization plots and electrochemical impedance spectroscopy technique were used. The results showed that the top PPy homopolymer film provided an effective barrier property on CS/ZnNi/PANi electrode and a remarkable anodic protection to substrate for longer exposure time.

The electroplating process of zinc–nickel system under perpendicular magnetic field from chloride bath

An investigation of the magnetic flux effect with an intensity of up to 1 T on the electroplating of Zn–Ni alloys was performed, taking into consideration the resistance and configuration of the electrode surface. Significant changes in the potential deposition, composition, and morphology were observed under perpendicular magnetic flux within the presence of NH4Cl. Additionally, the obtained results indicate that the magnetic flux supports the desorption of hydrogen. The chemical composition of the deposited alloys was found to be more affected by the magnetic field in the presence of NH4Cl. In particular, the nickel content increased to 20% under B = 1 T. X-ray patterns revealed a γ-Ni5Zn21 and pure zinc phases. The morphology was also explored and discussed.

The Performance of Zn-Ni Alloy Coating Electrodeposited from Stabilized Bath

A metallic part corrodes when it undergoes electrochemical reactions which cause the surface and structural deterioration of the metal. Through electroplating, metallic components can be protected from corrosion by coating them with Zn-Ni alloys. This study examined the electrodeposition of a Zn-Ni alloy film on a steel substrate from a chloride bath containing ethylene-diamine-tetraacetic acid (EDTA). A Pourbaix diagram using the OLI software was used to determine the stability of the Zn-Ni plating bath and the suppression of hydrogen evolution reaction (HER). Comparing the composition of Zn-Ni coating deposited in the EDTA bath with the pure Zn-Ni coating, the EDTA bath yielded higher deposition thickness and an average crystallite size reduction. The Zn-Ni coating deposited from the EDTA bath has a lower dissolution rate and better corrosion resistance properties than the non-EDTA bath. Polarization tests exhibited that the Zn-Ni alloy deposited from 0.119 mol/l EDTA bath at 20 mA/cm2 current density showed lower corrosion current (Icorr) and more positive corrosion potential (Ecorr). Atomic force microscopy (AFM) and Vickers microhardness testing were used to characterize the morphological properties, topographic structures, and microhardness of Zn-Ni coatings.

Role of Ni species in ZnO supported on Silicalite-1 for efficient propane dehydrogenation

Propane dehydrogenation (PDH) is one of the most effective technologies to produce propene. Non-noble zinc-based catalysts have paid increasing attention because of low cost and nontoxic, compared with industrial Pt and Cr-based catalysts. However, they often suffer from limited catalytic activity and poor stability. Here, we introduced moderate Ni into ZnO supported Silicalite-1 zeolite to increase catalytic activity and stability simultaneously. Zn 2+ was the definite active site and NiZn alloy facilitated the sluggish H recombination into H 2 via reverse spillover. Furthermore, the introduction of Ni increased Lewis acid strength caused by electron transfer from ZnO to NiZn alloy, contributing to improved stability. For resulted 0.5NiZn/S-1, propene formation rate was 0.18 mol C 3 H 6 ·(g Zn) −1 ·h −1 at 550 °C, which was above 1.5 times higher than that over Zn/S-1 without Ni. Under stability test, the deactivation of 0.5NiZn/S-1 was 0.019 h −1 , which was only 1/10 of that over Zn/S-1.

Barrel electroplating of Zn-Ni alloy coatings from a modified deep eutectic solvent

ABSTRACT Here the authors report the electroplating of Zn-Ni alloy on mild steel components from a modified deep eutectic solvent (DES), Ethaline, through a combination of barrel-plating and pulse-plating processes. The Ethaline electrolyte, a eutectic mixture of choline chloride (ChCl) and ethylene glycol (EG), was modified with propylene carbonate (PC) as a co-solvent together with the addition of boric acid to control deposit morphology and to suit the barrel plating system. A coating of γ-phase Zn-Ni alloy with 12–16% Ni was formed uniformly on mild steel screws and small components and the coating performed well as a sacrificial anti-corrosion layer. These findings are reported as part of an Innovate UK funded collaboration between university and industry partners, and included here are also the results of a scale-up pilot demonstrator system installed at E.C. Williams Ltd. (UK). It is concluded that the barrel plating of components using these materials and methods is very effective on a medium-scale and that the specification and performance of the coating is comparable with that from aqueous media. However, further development of this process may be limited by low current efficiency and the high relative cost of DES media.

Strong Magnetic-Field-Engineered Porous Template for Fabricating Hierarchical Porous Ni-Co-Zn-P Nanoplate Arrays as Battery-Type Electrodes of Advanced All-Solid-State Supercapacitors.

The sluggish charge transport kinetics that exist in the energy storage process of all-solid-state supercapacitors (ASSSCs) can be improved by designing open hierarchical porous structures for binder-free electrodes. Herein, a template-directed strategy is developed to fabricate open hierarchical porous Ni-Co-Zn-P nanoplate arrays (NCZP6T) through phosphating the electrodeposited NiCo-LDH nanosheets loaded on a template. At first, porous conductive NiZn alloy nanoplate arrays are rationally devised as the template by a strong magnetic field (SMF)-assisted electrodeposition. The Lorentz force caused by coupling the SMF with the electrical current induces a magnetohydrodynamic (MHD) flow (including the micro-MHD flow), which homogenizes the deposition coating, tunes the nucleation and growth of the NiZn alloy, and produces pores in the nanoplates. The open hierarchical porous structure offers a larger specific surface area and pore volume for accelerating charge transport and gives a synergistic effect between the inner porous conductive NiZn array template and the outer electrochemical active phosphides for high-performance hybrid ASSSCs. Accordingly, the battery-type electrode of NCZP6T shows a much higher specific capacitance of 3.81 F cm-2 at 1 mA cm-2, enhanced rate capability, and remarkable cycling stability at progressively varying current densities. Finally, the NCZP6T//FeS ASSSC delivers a high energy density of 77 μW h cm-2 at a large power density of 12 mW cm-2, outperforming most state-of-the-art supercapacitors.

Effects of Composition on the Electromagnetic Wave Shielding/Absorption and Corrosion in Zn-Ni Alloy Thin Film

In the Fourth industrial age, there is increasing use of electronic devices with high frequency (GHz) operating circuits for radio wave transmission/reception. This can lead to electromagnetic noise, and malfunctions in nearby devices. Electromagnetic shielding technology has emerged as an important way of preventing device malfunctions due to noise, and interest in shielding materials for electromagnetic waves has also increased. To allow compact integration and light weight electronic devices, highly efficient, thin and multifunctional film materials are required. This study selected the Zn-Ni alloy, which has adequate corrosion resistance, to protect the metal parent material of electronic components. Various compositions of the alloy were deposited using magnetron sputtering. Phase formation and composition were confirmed through XRD and SEM and EDS. The surface resistance of the thin films was measured using the 4point probe method, to calculate the shielding rate of the thin films. The electromagnetic wave shielding/absorption rate then measured according to frequency and the results compared with the calculated values. Corrosion resistance was evaluated with a polarization test. The far field electromagnetic shielding/absorption rate increased as the Zn content increased, up to 52 dB in a film with 70 at% of Zn. Corrosion resistivity behavior was the opposite. However, the Ni5Zn21 phase formation, which occurred in films with lower Zn composition, helped to improve electromagnetic absorption in the near field as well as corrosion resistivity. Therefore, the optimum composition of the Zn-Ni films was provisionally determined to be around Ni: Zn = 43:57 for electronic devices using electromagnetic waves in the near field range.

Effect of Ni Concentration on the Surface Morphology and Corrosion Behavior of Zn-Ni Alloy Coatings

This research work aims to develop electrodeposited Zn-Ni alloy coatings with controlled dissolution tendencies on a mild steel substrate. The varying Ni concentration in the electroplating bath, i.e., 10, 15, 20 and 25 g·L−1, affected the surface morphology and electrochemical properties of the deposited Zn-Ni alloy coatings. SEM and EDS analysis revealed the resulting variation in surface morphology and composition. The electrochemical behavior of different coatings was evaluated by measuring the open circuit potential and cyclic polarization trends in 3.5 wt.% NaCl solution. The degradation behavior of the electrodeposited Zn-Ni coatings was estimated by conducting a salt spray test for 96 h. The addition of Ni in the coating influenced the coating thickness and surface morphology of the coatings. The coating thickness decreased from 38.2 ± 0.5 μm to 20.7 ± 0.5 μm with the increase in Ni concentration. Relatively negative corrosion potential (<−1074 ± 10 mV) of the Zn-Ni alloy coatings compared to the steel substrate (−969 mV) indicated the sacrificial dissolution behavior of the Zn-rich coatings. On the other hand, compared to the pure Zn (26.12 mpy), ~4 times lower corrosion rate of the Zn-Ni coating (7.85 mpy) was observed by the addition of 25 g·L−1 Ni+2 in the bath solution. These results highlighted that the dissolution rate of the sacrificial Zn-Ni alloy coatings can effectively be tuned by the addition of Ni in the alloy coating during the electrodeposition process.

Synergistic Effect of Brightener and Solution Temperature on the Electrodeposition Behavior of Zn-Ni Alloy from Alkaline Zincate Solution

Synergistic Effect of Brightener and Solution Temperature on the Electrodeposition Behavior of Zn-Ni Alloy from Alkaline Zincate Solution