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1 – 9 of 9Zhengwei Song, Shengjian Zhang, Lifeng Ding, Xuejing Wu and Ning Long
The purpose of this paper was prepared a Ni-based superhydrophobic coating on the surface of copper to enhence its corrosion resistance. The superhydrophobic coating (SHPC) has…
Abstract
Purpose
The purpose of this paper was prepared a Ni-based superhydrophobic coating on the surface of copper to enhence its corrosion resistance. The superhydrophobic coating (SHPC) has proven to be an effective surface treatment in corrosion protection. In this paper, a Ni-based SHPC was prepared on the surface of copper (Cu) to enhance its corrosion resistance.
Design/methodology/approach
The coating was prepared through a two-step electrodeposition process. The first step involves the formation of a micro-nano structure Ni layer formed by an electrodeposition process. Subsequently, the polysiloxane layer was deposited on the Ni surface to create an SHPC. The morphology, composition, structure, wettability and corrosion resistance of the coating were characterized and discussed.
Findings
The results show that the water contact angle of the as-prepared coating reaches 155.5°±1.0°. The corrosion current density (icorr = 3.90 × 10−9 A·cm−2) decreased by three orders of magnitude compared to the substrate, whereas |Z|f = 0.01 Hz (2.40 × 106 Ω·cm2) increased by three orders of magnitude. It indicated that the prepared coating has excellent superhydrophobicity and high corrosion resistance, which can provide better protection for the substrate.
Originality/value
The prepared coating provides long-lasting protection for Cu and other metals and offers valuable data for developing SHPCs.
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Zhengwei Song, Zhi-Hui Xie, Lifeng Ding and Shengjian Zhang
This paper aims to comprehensively review the preparation methods of superhydrophobic surfaces (SHPS) for corrosion protection of Mg alloy in recent years.
Abstract
Purpose
This paper aims to comprehensively review the preparation methods of superhydrophobic surfaces (SHPS) for corrosion protection of Mg alloy in recent years.
Design/methodology/approach
The preparation methods, wettability and corrosion resistance of SHPS on Mg alloy in the past three years are systematically described in this paper.
Findings
Two types of SHPS, including single-layer and multilayer coatings for corrosion protection of Mg alloy are summarized. Preparing multilayered coatings with multifunction is the current trend in developing SHPS on Mg alloy.
Originality/value
This paper reviewed the preparation methods and corrosion resistance of SHPS on Mg alloys. It provides a valuable reference for researchers to develop highly durable SHPS with excellent corrosion resistance for Mg alloys.
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Shucai Yang, Dawei Wang and Zhanjun Xiao
The purpose is to explore the improvement mechanism of coating and laser micro-texture on the surface properties of cemented carbide, so as to give full play to the technical…
Abstract
Purpose
The purpose is to explore the improvement mechanism of coating and laser micro-texture on the surface properties of cemented carbide, so as to give full play to the technical advantages of both and improve the overall surface properties of the material.
Design/methodology/approach
The surface hardness of the coating was measured by a microhardness tester, the surface element composition of the coating was tested by an energy spectrum analyzer and the phase was measured by an X-ray diffractometer to observe the surface morphology after the friction and wear experiment.
Findings
Laser will generate new oxide and nitride films on the surface of the coating, which will improve the hardness of the coating surface and the bonding strength between the coating and the substrate. The surface micro-texture can collect wear debris during the friction process, reduce abrasive wear and play a good role in inhibiting the expansion of the coating failure zone.
Originality/value
Most of the research on traditional laser coating is to process micro-texture first and then coating. This study is the opposite. In this paper, the modification effect of laser on the coating surface is explored, and the parameters of laser and coating are optimized, which paves the way for the subsequent milling experiments of textured coating tools.
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Dexin Chen, Hongyuan He, Zhixin Kang and Wei Li
This study aims to review the current one-step electrodeposition of superhydrophobic coatings on metal surfaces.
Abstract
Purpose
This study aims to review the current one-step electrodeposition of superhydrophobic coatings on metal surfaces.
Design/methodology/approach
One-step electrodeposition is a versatile and simple technology to prepare superhydrophobic coatings on metal surfaces.
Findings
Preparing superhydrophobic coatings by one-step electrodeposition is an efficient method to protect metal surfaces.
Originality/value
Even though there are several technologies, one-step electrodeposition still plays a significant role in producing superhydrophobic coatings.
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Rilwan Kayode Apalowo, Mohamad Aizat Abas, Muhamed Abdul Fatah Muhamed Mukhtar, Fakhrozi Che Ani and Mohamad Riduwan Ramli
This study aims to investigate the reliability issues of microvoid cracks in solder joint packages exposed to thermal cycling fatigue.
Abstract
Purpose
This study aims to investigate the reliability issues of microvoid cracks in solder joint packages exposed to thermal cycling fatigue.
Design/methodology/approach
The specimens are subjected to JEDEC preconditioning level 1 (85 °C/85%RH/168 h) with five times reflow at 270°C. This is followed by thermal cycling from 0°C to 100°C, per IPC-7351B standards. The specimens' cross-sections are inspected for crack growth and propagation under backscattered scanning electronic microscopy. The decoupled thermomechanical simulation technique is applied to investigate the thermal fatigue behavior. The impacts of crack length on the stress and fatigue behavior of the package are investigated.
Findings
Cracks are initiated from the ball grid array corner of the solder joint, propagating through the transverse section of the solder ball. The crack growth increases continuously up to 0.25-mm crack length, then slows down afterward. The J-integral and stress intensity factor (SIF) values at the crack tip decrease with increased crack length. Before 0.15-mm crack length, J-integral and SIF reduce slightly with crack length and are comparatively higher, resulting in a rapid increase in crack mouth opening displacement (CMOD). Beyond 0.25-mm crack length, the values significantly decline, that there is not much possibility of crack growth, resulting in a negligible change in CMOD value. This explains the crack growth arrest obtained after 0.25-mm crack length.
Practical implications
This work's contribution is expected to reduce the additional manufacturing cost and lead time incurred in investigating reliability issues in solder joints.
Originality/value
The work investigates crack propagation mechanisms of microvoid cracks in solder joints exposed to moisture and thermal fatigue, which is still limited in the literature. The parametric variation of the crack length on stress and fatigue characteristics of solder joints, which has never been conducted, is also studied.
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Zhao Yuhang, Zhicai Yu, Hualing He and Huizhen Ke
This study aims to fabricate a multifunctional electromagnetic interference (EMI) shielding composite fabric with simultaneous high-efficiency photothermal conversion and Joule…
Abstract
Purpose
This study aims to fabricate a multifunctional electromagnetic interference (EMI) shielding composite fabric with simultaneous high-efficiency photothermal conversion and Joule heating performances.
Design/methodology/approach
A multifunctional polypyrrole (PPy) hydrogel/multiwalled carbon nanotube (MWCNT)/cotton EMI shielding composite fabric (hereafter denoted as PHMC) was prepared by loading MWCNT onto tannin-treated cotton fabric, followed by in situ crosslinking-polymerization to synthesize three-dimensional (3D) conductive networked PPy hydrogel on the surface of MWCNT-coated cotton fabric.
Findings
Benefiting from the unique interconnected 3D networked conductive structure of PPy hydrogel, the obtained PHMC exhibited a high EMI-shielding effectiveness vale of 48 dB (the absorbing electromagnetic wave accounted for 84%) within a large frequency range (8.2–12.4 GHz). Moreover, the temperature of the laminated fabric reached 54°C within 900 s under 15 V, and it required more than 100 s to return to room temperature (28.7°C). When the light intensity was adjusted to 150 mW/cm2, the PHMC temperature was about 38.2°C after lighting for 900 s, indicating high-efficiency electro-photothermal effect function.
Originality/value
This paper provides a novel strategy for designing a type of multifunctional EMI shielding composite fabric with great promise for wearable smart garments, EMI shielding and personal heating applications.
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Keywords
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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Wen Pin Gooi, Pei Ling Leow, Jaysuman Pusppanathan, Xian Feng Hor and Shahrulnizahani Mohammad Din
As one of the tomographic imaging techniques, electrical capacitance tomography (ECT) is widely used in many industrial applications. While most ECT sensors have electrodes placed…
Abstract
Purpose
As one of the tomographic imaging techniques, electrical capacitance tomography (ECT) is widely used in many industrial applications. While most ECT sensors have electrodes placed around a cylindrical chamber, the planar ECT sensor has been investigated for depth and defect detection. However, the planar ECT sensor has limited height and depth sensing capability due to its single-sided assessment with the use of only a single-plane design. The purpose of this paper is to investigate a dual-plane miniature planar 3D ECT sensor design using the 3 × 3 matrix electrode array.
Design/methodology/approach
The sensitivity map of dual-plane miniature planar 3D ECT sensor was analysed using 3D visualisation, the singular value decomposition and the axial resolution analysis. Then, the sensor was fabricated for performance analysis based on 3D imaging experiments.
Findings
The sensitivity map analysis showed that the dual-plane miniature planar 3D ECT sensor has enhanced the height sensing capability, and it is less ill-posed in 3D image reconstruction. The dual-plane miniature planar 3D ECT sensor showed a 28% improvement in reconstructed 3D image quality as compared to the single-plane sensor set-up.
Originality/value
The 3 × 3 matrix electrode array has been proposed to use only the necessary electrode pair combinations for image reconstruction. Besides, the increase in number of electrodes from the dual-plane sensor setup improved the height reconstruction of the test sample.
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Mohammad Javad Jafari, Elham Akhlaghi Pirposhteh, Mohadese Farhangian, Soheila Khodakarim Ardakani, Elaheh Tavakol, Somayeh Farhang Dehghan and Amin Khalilinejad
The aim of this study is to optimize the electrospinning parameters used in the production process of polyvinyl chloride (PVC) nanofibers.
Abstract
Purpose
The aim of this study is to optimize the electrospinning parameters used in the production process of polyvinyl chloride (PVC) nanofibers.
Design/methodology/approach
The response surface methodology (RSM) was used to determine the experimental design. The 30 nanofiber prototypes candidates were electrospun using a needle-based electrospinning machine. PVC polymer, N-dimethyl formamide and tetrahydrofuran solvents were used to prepare the electrospinning solution.
Findings
The electrospun nanofibers had a mean diameter of 386 ± 136.57 nm, in the range of 200−412 nm. The mean porosity was 31.60 ± 6.37% in the range of 15.33−41.53%. The webs made from electrospun nanofibers had a mean pressure loss of 194.23 ± 47.7 pa in the range of 124−300 pa. The highest statistically significant correlation was observed between solution concentration and nanofiber diameter (r = 0.756, p < 0.05).
Originality/value
The optimal electrospinning parameters were determined to be: a solution concentration of 11 weight percent, a voltage of 16.5 kV, a needle-collector distance of 13.5 cm and an electrospinning duration of 4 h.
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