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1 – 10 of over 2000Simbarashe Fashu and Rajwali Khan
Thin coatings are of great importance to minimize corrosion attack of steel in different environments. A review of recent work on electrodeposition and corrosion performance of Zn…
Abstract
Purpose
Thin coatings are of great importance to minimize corrosion attack of steel in different environments. A review of recent work on electrodeposition and corrosion performance of Zn-Ni-based alloys for sacrificial corrosion protection of ferrous substrates is presented. The purpose of this study is to provide a systematic comparison of the corrosion resistances of Zn-Ni alloy coatings. The review contains key and outstanding comparisons of references for the period from 2007 to 2017. Binary and ternary Zn-Ni-based alloys were compared and contrasted to provide a good knowledge basis for selection of best coating system to steel substrates.
Design/methodology/approach
This article is a review article.
Findings
Zn-Ni-(X) alloys show great potential for replacing Cd metal in corrosion protection of steel substrates.
Practical implications
The research on plating of binary Zn-Ni alloys from aqueous electrolytes is now well advanced and these alloys show improved corrosion resistance compared to pure Zn. Pulse plated and compositionally modulated multilayer Zn-Ni alloy coatings showed enhanced corrosion properties compared to direct plated Zn-Ni coatings of similar composition.
Originality/value
The work on electrodeposition of Zn-Ni based alloys from ionic liquids is still scarce, yet these liquids show great promise in improving corrosion resistance and reducing coating thickness when compared to aqueous electrolytes. Advanced plating techniques in ionic liquids such as electromagnetic, compositionally modulated multilayer, pulse plating, ternary alloys and composites should be considered as these electrolytes avoid water chemistry and associated defects.
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Elnaz Moslehifard, Sanaz Ghasemzadeh and Farzad Nasirpouri
The purpose of this paper (in vitro) study was to determine the effect of pH of artificial saliva on the corrosion behavior of a Ni-Cr-Mo alloy at 37 ± 1°C.
Abstract
Purpose
The purpose of this paper (in vitro) study was to determine the effect of pH of artificial saliva on the corrosion behavior of a Ni-Cr-Mo alloy at 37 ± 1°C.
Design/methodology/approach
The corrosion behavior of a commercially available Ni-Cr-Mo base dental alloy was studied by potentiodynamic polarization and electrochemical impedance spectroscopy techniques. The effect of pH on corrosion and Ni ion release was also investigated by scanning electron microscopy and atomic absorption spectroscopy.
Findings
The results suggested that the order of corrosion rate was: pH3 > pH5 > pH9 > pH7. Corrosion rate in pH3 was significantly different with other pH levels. Nickel depletion significantly occurred in alloy without passivation. The corrosion resistance and ion release of Ni-Cr-Mo alloys in different pH levels of artificial saliva depended on the stability of the passive layer. Acidic pH level severely corrodes Ni-Cr-Mo base metal alloys and increases Ni ion release.
Originality/value
This manuscript describes the relationship between corrosion rate and nickel ion release of a dental Ni-Cr-Mo base alloy as a function of saliva pH examined by electrochemical impedance spectroscopy (EIS), polarization, scanning electron microscopy and energy dispersive X-ray spectroscopy in artificial saliva. The main novelty of this work includes the material/structure/corrosion relationship in artificial saliva with different pH. This property would be very interesting for dental materials applications and clinical dentistry.
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Bukola Joseph Babalola, Ojo Jeremiah Akinribide, Olukayode Samuel Akinwamide and Peter Apata Olubambi
During the operation of nickel-based alloys as blades and discs in turbines, the sliding activity between metallic surfaces is subjected to structural and compositional changes…
Abstract
Purpose
During the operation of nickel-based alloys as blades and discs in turbines, the sliding activity between metallic surfaces is subjected to structural and compositional changes. In as much as friction and wear are influenced by interacting surfaces, it is necessary to investigate these effects. This study aims to understand better the mechanical and tribological characteristics of Ni-17Cr-10X (X = Mo, W, Ta) ternary alloy systems developed via spark plasma sintering (SPS) technique.
Design/methodology/approach
Nickel-based ternary alloys were fabricated via SPS technique at 50 MPa, 1100 °C, 100 °C/min and a dwell time of 10 mins. Scanning electron microscopy, X-Ray diffraction, energy dispersive X-ray spectroscopy, nanoindentation techniques and tribometer were used to assess the microstructure, phase composition, elemental dispersion, mechanical and tribological characteristics of the sintered nickel-based alloys.
Findings
The outcome of the investigation showed that the Ni-17Cr10Mo alloy exhibited the highest indentation hardness value of 8045 MPa, elastic modulus value of 386 GPa and wear resistance. At the same time, Ni-17Cr10W possessed the least mechanical and wear properties.
Originality/value
It can be shown that the SPS technique is efficient in the development of nickel-based alloys with good elemental distribution and without defects such as segregation of alloying elements, non-metallic inclusions. This is evident from the scanning electron microscopy micrographs.
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Mohammed S. Gumaan, Rizk Mostafa Shalaby, Mustafa Kamal Mohammed Yousef, Esmail A.M. Ali and E. E. Abdel-Hady
This study aims to investigate the structural, mechanical, thermal and electrical properties of tin–silver–nickel (Sn-Ag-Ni) melt-spun solder alloys. So, it aims to improve the…
Abstract
Purpose
This study aims to investigate the structural, mechanical, thermal and electrical properties of tin–silver–nickel (Sn-Ag-Ni) melt-spun solder alloys. So, it aims to improve the mechanical properties of the eutectic tin–silver (Sn-Ag) such as tensile strength, plasticity and creep resistance by adding different concentrations of Ni content.
Design/methodology/approach
Ternary melt-spun Sn-Ag-Ni alloys were investigated using x-ray diffractions, scanning electron microscope, dynamic resonance technique (DRT), Instron machine, Vickers hardness tester and differential scanning calorimetry.
Findings
The results revealed that the Ni additions 0.1, 0.3, 0.5, 0.7, 1, 3 and 5 Wt.% to the eutectic Sn-Ag melt-spun solder were added. The “0.3wt.%” of Ni was significantly improved its mechanical properties to efficiently serve under high strain rate applications. Moreover, the uniform distribution of Ag3Sn intermetallic compound with “0.3wt.%” of Ni offered the potential benefits, such as high strength, good plasticity consequently and good mechanical performance through a lack of dislocations and microvoids. The tensile results showed improvement in 17.63 per cent tensile strength (26 MPa), 21 per cent toughness (1001 J/m3), 22.83 per cent critical shear stress (25.074 MPa) and 11 per cent thermal diffusivity (2.065 × 10−7 m2/s) when compared with the tensile strength (21.416 MPa), toughness (790 J/m3), critical shear stress (19.348 MPa) and thermal diffusivity (1.487 × 10−7 m2/s) of the eutectic Sn-Ag. Slight increments have been shown for the melting temperature of Sn96.2-Ag3.5-Ni0.3 (222.62°C) and electrical resistivity to (1.612 × 10−7 Ω.m). It can be said that the eutectic Sn-Ag solder alloy has been mechanically improved with “0.3wt.%” of Ni to become a suitable alloy for high strain rate applications. The dislocation movement deformation mechanism (n = 4.5) without Ni additions changed to grain boundary sliding deformation mechanism (n = 3.5) with Ni additions. On the other hand, the elastic modulus, creep rate and strain rate sensitivity with “0.3wt.%” of Ni have been decreased. The optimum Ni-doped concentration is “0.7wt.%” of Ni in terms of refined microstructure, electrical resistivity, Young’s Modulus, bulk modulus, shear modulus, thermal diffusivity, maximum shear stress, tensile strength and average creep rate.
Originality/value
This study provides nickel effects on the structural of the eutectic Sn-Ag rapidly solidified by melt-spinning technique. In this paper, the authors have compared the elastic modulus of the melt-spun compositions which has been resulted from the tensile strength tester with these results from the DRT for the first time to best of the authors’ knowledge. This paper presents new improvements in mechanical and electrical performance.
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Haijing Sun, Jianing Cui, He Wang, Shuai Yang, Souavang Xaikoua, Yong Tan, Xin Zhou, Baojie Wang and Jie Sun
The purpose of this paper is to study the effect of temperature on Zn–Ni alloys in ChCl–Urea.
Abstract
Purpose
The purpose of this paper is to study the effect of temperature on Zn–Ni alloys in ChCl–Urea.
Design/methodology/approach
Based on cyclic voltammetry experiments, the deposition behavior and kinetics of the Zn–Ni alloy are studied. The nucleation process of the Zn–Ni alloy is studied in detail via chronoamperometry experiments. The effects of the deposition temperature on the microstructure, Ni content and phase composition of Zn–Ni alloy coatings are investigated via scanning electron microscopy and X-ray diffraction (XRD) combined with classical thermodynamics.
Findings
The results show that with increasing temperature, the reduction peak shifts toward a more positive electric potential, which is beneficial for the co-electric deposition process, and the diffusion coefficient is estimated. With increasing temperature, the nucleation process of the Zn–Ni alloy becomes a three-dimensional instantaneous nucleation, the typical kinetic parameters are determined using the standard 3D growth proliferation control model and the Gibbs free energy is estimated. The Zn–Ni alloy coatings are prepared via normal co-deposition. With increasing temperature, the degree of crystallinity increases, the coating gradually becomes uniform and compact and the XRD peak intensity increases.
Originality/value
The nucleation process of the Zn–Ni alloy at different temperatures is analyzed. The diffusion coefficient D and Gibbs free energy are calculated. The contribution of the three processes at different temperatures is analyzed. The effect of temperature on the morphology of the Zn–Ni alloy coatings is studied.
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Ao Zhang, Jian Zhang, Mingjun Zhang, Junyi Liu and Ping Peng
This paper aims to investigate the effect and mechanism of O atom single doping, Ce and O atoms co-doping on the interfacial microscopic behavior of brazed Ni-Cr/diamond.
Abstract
Purpose
This paper aims to investigate the effect and mechanism of O atom single doping, Ce and O atoms co-doping on the interfacial microscopic behavior of brazed Ni-Cr/diamond.
Design/methodology/approach
Using first-principles calculations, the embedding energy, work of separation, interfacial energy and electronic structures of Ni-Cr-O/diamond and Ni-Cr-O-Ce/diamond interface models were calculated. Then, the effect of Ce and O co-doping was experimentally verified through brazed diamond with CeO2-added Ni-Cr filler alloy.
Findings
The results show that O single-doping reduces the interfacial bonding strength between Ni-Cr filler alloy and diamond but enhances its interfacial stability to some extent. However, the Ce and O co-doping simultaneously enhances the interfacial bonding strength and stability between Ni-Cr filler alloy and diamond. The in-situ formed Ce-O oxide at interface impedes the direct contact between diamond and Ni-Cr filler alloy, which weakens the catalytic effect of Ni element on diamond graphitization. It is experimentally found that the fine rod-shaped Cr3C2 and Cr7C3 carbides are generated on diamond surface brazed with CeO2-added Ni-Cr filler alloy. After grinding, the brazed diamond grits, brazed with CeO2-added Ni-Cr filler alloy, present few fracture and the percentage of intact diamond reaches 67.8%. Compared to pure Ni-Cr filler alloy, the brazed diamond with CeO2-added Ni-Cr filler alloy exhibit the better wear resistance and the slighter thermal damage.
Originality/value
Using first-principles calculations, the effect of Ce and O atoms co-doping on the brazed diamond with Ni-Cr filler alloy is investigated, and the calculation results are verified experimentally. Through the first-principles calculations, the interface behavior and reaction mechanism between diamond and filler alloy can be well disclosed, and the composition of filler alloy can be optimized, which will be beneficial for synergistically realizing the enhanced interface bonding and reduced thermal damage of brazed diamond.
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Jianran Lv, Hongyao Shen and Jianzhong Fu
The purpose of this paper is to supplement and upgrade existing research on LPBF of NiTi alloys. Laser powder bed fusion (LPBF) is a promising method for fabricating…
Abstract
Purpose
The purpose of this paper is to supplement and upgrade existing research on LPBF of NiTi alloys. Laser powder bed fusion (LPBF) is a promising method for fabricating nickel–titanium (Ni–Ti) alloys. It is well known that the energy density is mainly adjusted through the scanning speed and laser power. Nevertheless, there is lack in research on the effects of separately adjusting the scanning speed and laser power on the properties of the final Ni–Ti components. On the other hand, although Ni-rich Ni–Ti alloys [such as Ni54(at.%)Ti] have great potential in structural applications because of their high hardness and good shape stability, at present, there are few studies focusing on this grade of Ni–Ti alloy.
Design/methodology/approach
In this work, the energy density was adjusted by changing the laser power and scanning speed separately, and the corresponding process parameters were used to fabricate Ni54(at.%)Ti alloys. The formability (including the relative density, impurity content, etc.) and tensile properties of the LPBF Ni54(at.%)Ti alloys fabricated with different combinations of process parameters were analyzed.
Findings
The effects of increasing the laser power and reducing the scanning speed on the properties of the LPBF Ni54(at.%)Ti alloys and the property differences between components manufactured with different combinations of laser power and scanning speed under the same energy density were analyzed. The optimal process parameters were selected to fabricate the components that achieved the highest ultimate tensile strength of 537 MPa, a high relative density of 98.23%, a relatively low impurity content (0.073 Wt.% of carbon and 0.06 Wt.% of oxygen) and an ideal pseudoelasticity (95% recovery rate loaded at 300 MPa).
Originality/value
The effects of increasing the laser power and reducing the scanning speed on the properties of LPBF Ni54(at.%)Ti alloys were studied in this paper. This work is an upgrade and supplement to the existing research on fabricating Ni-rich Ni–Ti alloys by the LPBF method.
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Z. Abdel Hamid, A.Y. El-Etre and M. Fareed
The purpose of this study is to investigate the effect of the incorporated zirconia (ZrO2) nanoparticles on the performance of the deposited layer Ni–Cu alloy on steel sheet.
Abstract
Purpose
The purpose of this study is to investigate the effect of the incorporated zirconia (ZrO2) nanoparticles on the performance of the deposited layer Ni–Cu alloy on steel sheet.
Design/methodology/approach
The aim was to produce Ni–Cu–ZrO2 nanocomposite coatings by electrodeposition technique and estimate the influence of ZrO2 nanoparticles on the performance of Ni–Cu alloy. The surface morphologies and chemical compositions of the deposited layers were assessed using scanning electron microscopy and energy-dispersive X-ray analysis, respectively. Nanoindentation was used as a well-advanced technique for measuring microhardness and Young’s modulus values of different coatings. The corrosion resistance in 3.5 per cent NaCl solution of electrodeposited films has been investigated.
Findings
The main conclusion is that the surface morphologies of Ni–Cu–ZrO2 nanocomposite coatings were fine granular compared with Ni–Cu alloy. The corrosion behavior illustrated that the incorporation of ZrO2 nanoparticles with Ni–Cu film improved the corrosion resistance. Significant improvement was also demonstrated in the hardness of nanocomposite coatings.
Social implications
The optimized industrial use of steel-coated Ni–Cu alloy with super properties. Consequently, a social benefit can be associated with the reduction in the corrosion rate and increases the microhardness and Young’s modulus.
Originality/value
The results presented in this work are an insight into understanding the incorporation of ceramic reinforcement with metal or alloy films (matrix) on carbon steel using the electrodeposition technique. The development of corrosion resistance of Ni–Cu alloys has been considered as a promising behavior. In this work, a consistent assessment of the results achieved on laboratory scale has been conducted.
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This paper aims to report a study of the influence of tungsten carbide (WC) nanoparticles on corrosion resistance properties of electroless nickel–phosphorus (Ni–P) coatings in…
Abstract
Purpose
This paper aims to report a study of the influence of tungsten carbide (WC) nanoparticles on corrosion resistance properties of electroless nickel–phosphorus (Ni–P) coatings in NaCl solution.
Design/methodology/approach
The morphology of Ni–P–WC nanocomposite coatings was observed by scanning electron microscopy (SEM). The anodic polarization curves, electrochemical impedance spectra (EIS) and weight loss measurements were used to study the corrosion resistance properties of Ni–P–WC nanocomposite coatings in NaCl solution.
Findings
The WC nanoparticles content in the coatings increased with the increase of its concentration in the bath, and the WC nanoparticles are uniformly distributed in Ni–P alloy matrix. The results showed that the incorporation of WC nanoparticles elevated the corrosion resistance properties of Ni–P alloy matrix.
Originality/value
This study shows that the corrosion resistance was improved by the addition of WC nanoparticles to the Ni–P alloy matrix.
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This paper aims to study the effect of SiO2 nano‐particulates on the corrosion behaviour of Ni‐W/SiO2 nanocomposite coatings.
Abstract
Purpose
This paper aims to study the effect of SiO2 nano‐particulates on the corrosion behaviour of Ni‐W/SiO2 nanocomposite coatings.
Design/methodology/approach
Weight loss measurements, electrochemical measurements and scanning electron microscope were used to study the corrosion behaviour of Ni‐W/SiO2 nanocomposite coatings in NaCl solution.
Findings
The incorporation of SiO2 nano‐particulates into the Ni‐W alloy matrix significantly increased the corrosion resistance. The improvement in corrosion resistance was due to the SiO2 nano‐particulates acting as physical barriers to the corrosion process by filling in crevices, gaps and microscopic holes on the surface of the Ni‐W alloy.
Originality/value
This study highlights the use of nano‐particulates for the control of Ni‐W alloy coating corrosion and opens a new route for industry in the anti‐corrosion field.
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