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1 – 10 of 217
Article
Publication date: 13 November 2007

Yingwu Yao

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.

Details

Anti-Corrosion Methods and Materials, vol. 54 no. 6
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 7 April 2015

C.S. Chew, R. Durairaj, A. S. M. A. Haseeb and B. Beake

The purpose of this paper is to investigate the hardness and elastic modulus on interfacial phases formed between Sn-3.5Ag solder and Ni-18 at. % W alloy film by nanoindentation…

Abstract

Purpose

The purpose of this paper is to investigate the hardness and elastic modulus on interfacial phases formed between Sn-3.5Ag solder and Ni-18 at. % W alloy film by nanoindentation. It has been found that a ternary amorphous Sn-Ni-W layer formed below Ni3Sn4 IMC at the interface. In this study, mechanical properties of the IMC formed between SA solder and Ni-18 at. % W film after six times reflows were performed by nanoindentation.

Design/methodology/approach

The characterization was carried at 25°C, and 100 indents were generated. The elastic modulus and hardness were investigated.

Findings

The results showed that hardness of Ni3Sn4 IMC was higher than amorphous Sn-Ni-W phase. A slight bigger indent was observed on the Sn-Ni-W layer compared with that on the Ni3Sn4 IMC. Lower topographical height in the Sn-Ni-W layer indicated that the Sn-Ni-W phase was softer compared with the Ni3Sn4 IMC. The lower hardness and soft Sn-Ni-W phase is significantly related to the amorphous structure that formed through solid-state amorphization.

Originality/value

There are no publications about the indentation on the interfacial between the Ni-W layer and the Sn-Ag solder.

Details

Soldering & Surface Mount Technology, vol. 27 no. 2
Type: Research Article
ISSN: 0954-0911

Keywords

Article
Publication date: 10 December 2019

Zeinab Abdel Hamid, H.B. Hassan and Mohamed Sultan

The improvement of the hydrogen evolution reaction (HER) performance requires more efficient and inexpensive electrocatalysts. The purpose of this study is to prepare Ni-W and Ni-W

Abstract

Purpose

The improvement of the hydrogen evolution reaction (HER) performance requires more efficient and inexpensive electrocatalysts. The purpose of this study is to prepare Ni-W and Ni-W-P thin films using the electrodeposition technique using a pulse current and investigate their behaviors toward HER in an acidic solution.

Design/methodology/approach

The aim is to prepare Ni-W and Ni-W-P films by the electrodeposition technique using a pulse current and estimate their performance for the HER. The surface morphologies and chemical compositions of the deposited films were assessed using scanning electron microscopy, energy-dispersive X-ray analysis and X-ray diffraction. Linear sweep voltammetry, chronoamperometry, Tafel plots and electrochemical impedance spectroscopy were used to evaluate the prepared electrodes toward the hydrogen evolution process.

Findings

The main conclusion is that the surface morphology of Ni–W deposited film is a crystalline structure, while that of Ni-W-P deposit is an amorphous structure. HER activity on Ni-W electrodes increases with decreasing the Wt.% of W to 7.83 Wt.% in the prepared electrodes. In addition, the presence of P enhances HER activity, which increases with increasing the Wt.% of P in the prepared Ni-W-P electrodes. Both Ni-W (7.83 Wt.% W) and Ni-W-P (20.34 Wt.% P), which have been prepared at 8 A dm−2 display the best performance toward HER compared to the other prepared electrodes. They exhibit high catalytic activities toward HER, which is evidenced by high hydrogen evolution current density values of 9.52 and 33.98 mA cm−2, low onset potentials of −0.73 and −0.63 V, low Tafel slopes of −125 mV/dec, high exchange current densities of 0.058 and 0.20 mA cm−2, low charge transfer resistances (Rct) of 226.28 and 75.8 ohm·cm2 for Ni-W (7.83  Wt.% W) and Ni-W-P (20.34  Wt.% P), respectively; moreover, they exhibited considerable stabilities too.

Originality/value

The results presented in this work are an insight into understanding the performance of the prepared Cu electrodes coated by Ni-W and Ni-W-P films toward HER. In this work, a consistent assessment of the results achieved on laboratory scale has been conducted.

Article
Publication date: 24 March 2022

Ya-Peng Jia, Wan-Chang Sun, Yan Xiao, Jing-Pei Liu, Cong-Xiao Zhang, Tong-Qiang Zhang and Ze-Feng Hou

This paper aims to research the effect of different concentrations for Nd(NO3)3 and Ce(NO3)3 on the microstructures and corrosion resistance of Ni-W-P composite coatings through…

Abstract

Purpose

This paper aims to research the effect of different concentrations for Nd(NO3)3 and Ce(NO3)3 on the microstructures and corrosion resistance of Ni-W-P composite coatings through electroless plating method.

Design/methodology/approach

Scanning electron microscope, attached energy dispersive spectroscopy system and X-ray diffraction were used in this work. Meanwhile, the immersion test and electrochemical tests were used to characterize the corrosion behavior of the coating.

Findings

The coatings prepared at 1.00 g·L−1 Nd(NO3)3 exhibit a dense structure and high phosphorus content (12.38 wt.%). In addition, compared to the addition of Ce(NO3)3, when Nd(NO3)3 was introduced at a concentration of 1.00 g·L−1, the minimum corrosion rate of the coating was 1.209 g·m−2·h−1, with a noble Ecorr (−0.29 V) and lower Icorr (8.29 × 10−4 A·cm−2).

Originality/value

The effects of rare earths on the deposition and corrosion resistance mechanisms of Ni-W-P composite coatings were explored, with the rare earth elements promoting the deposition of nickel and tungsten atoms. Simultaneously, the amorphization of the coating increases, which excellently enhances the corrosion resistance of the coating.

Details

Anti-Corrosion Methods and Materials, vol. 69 no. 3
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 May 1935

W.H. Hatfield

NEARLY twenty years have passed since the author had the pleasure of giving a paper on the same subject to this Society. Progress in the meantime as regards the means and art of…

Abstract

NEARLY twenty years have passed since the author had the pleasure of giving a paper on the same subject to this Society. Progress in the meantime as regards the means and art of flying has been not only sustained, but rapid, as is brought out by the simple facts contained in Table I. The amazing technology is well represented by the De Havilland Comet, which develops 460 h.p. with a weight ratio of 12 lb. per h.p. It therefore becomes interesting and perhaps useful to determine the extent to which metallurgy has contributed and is contributing.

Details

Aircraft Engineering and Aerospace Technology, vol. 7 no. 5
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 19 April 2022

Sait Gül, Çağlar Sivri and Ozan Rıdvan Aksu

The purpose of this paper is to determine which criteria should be taken into account while choosing face masks for pandemic times and to what extent their effects are.

Abstract

Purpose

The purpose of this paper is to determine which criteria should be taken into account while choosing face masks for pandemic times and to what extent their effects are.

Design/methodology/approach

Nine face mask alternatives were evaluated based on the assessments of their performance with respect to twelve attributes. Seven experts were asked to evaluate the mask alternatives and the influences among attributes. In gathering expert judgments, spherical fuzzy number-based linguistic terms were utilized in the study to provide a more comprehensive representation domain to them.

Findings

According to the results, the most important attributes are found as material type, cost and bacteria–virus protection level. The best face mask is N95, which is followed by respirators and surgical masks.

Research limitations/implications

The implication of the research is to evaluate face masks in terms of criteria such as physical, performance, protection and cost to decide on what basis they were selected as a personal protective equipment (PPE) based on expert assessments. This is useful in selection of the right face mask with optimum performance and provides guidance to the general public and profession specific groups for this purpose. The face mask companies might be also benefitted from the implications of the present study in their design and research and development (R&D) operations.

Originality/value

The preference ranking of the face mask alternatives has not been studied in detail yet in the literature. Focusing on this issue, the present study provides a comprehensive assessment of the selection criteria of face masks in the pandemic era.

Details

International Journal of Clothing Science and Technology, vol. 34 no. 5
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 29 June 2023

He Chuang, Wang Fan, Liu Zhicheng and Kong Dejun

The purpose of this study is to investigate the effect of laser scanning speed (LSS) on the corrosive-tribological performance of Ni-60%WC coating in Wusu mine water, which was…

Abstract

Purpose

The purpose of this study is to investigate the effect of laser scanning speed (LSS) on the corrosive-tribological performance of Ni-60%WC coating in Wusu mine water, which was beneficial to improve the friction–wear performance of cylinder liner on water injection pump.

Design/methodology/approach

Ni-60%WC coatings were fabricated on 45 steel by laser cladding, and the microstructure and tribological performance was analyzed using a super depth of field microscope and ball-on-plate friction tester, and the wear mechanism was also discussed.

Findings

At room temperature (RT, 25 ± 2 °C), the average coefficients of friction of substrate and Ni-60%WC coatings fabricated at the LSS of 6, 10, 12 and 14 mm/s are 0.48 ± 0.08, 0.23 ± 0.01, 0.21 ± 0.05, 0.22 ± 0.02 and 0.25 ± 0.04, respectively, and the corresponding wear rates are 8.755 × 104, 4.525 × 103, 1.539 × 103, 1.957 × 103 and 2.743 × 103 µm3·s–1·N–1, respectively, showing that the coating fabricated at the LSS of 10 mm/s has best friction reduction and wear resistance. The wear mechanism of Ni-60%WC coating is abrasive wear, fatigue wear and oxidative wear, which is resulted from the WC particles with the high-hardness.

Originality/value

Ni-60%WC coatings were first applied for cylinder liner, and the effect of laser scanning speed on its tribological performance was investigated.

Details

Industrial Lubrication and Tribology, vol. 75 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 2 February 2022

Li Wei and Kong Dejun

The purpose of this study is to investigate the effect of Y2O3 mass fraction on the electrochemical corrosion performance of CrNi coating, which provided a foundation for the…

140

Abstract

Purpose

The purpose of this study is to investigate the effect of Y2O3 mass fraction on the electrochemical corrosion performance of CrNi coating, which provided a foundation for the performance optimization of CrNi coatings.

Design/methodology/approach

CrNi coatings with the different Y2O3 mass fractions were fabricated on AISI H13 steel by laser cladding, and the effect of Y2O3 mass fraction on the electrochemical performance of CrNi coating in 3.5% NaCl solution was investigated using an electrochemical workstation.

Findings

The electrochemical corrosion performance of CrNi coating enhances with the increase of Y2O3 mass fraction, and the CrNi–15%Y2O3 coating has the largest polarization resistance and the lowest corrosion current density, which displays the best electrochemical performance among the CrNi–5%Y2O3, –10%Y2O3 and –15%Y2O3 coatings. The protective films are formed with the increase of Y2O3 mass fraction, which inhibits the occurrence of electrochemical corrosion.

Originality/value

The Y2O3 was first added to the CrNi coating to improve its electrochemical corrosion performance, and the influence of Y2O3 on the corrosion resistance of the CrNi coating was discussed by the corrosion model.

Details

Anti-Corrosion Methods and Materials, vol. 69 no. 2
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 November 1956

E.W. Parkes

WHEN a structure is subjected to a recurrent cycle of loading a number of different types of deformation may be set up. The structure may remain elastic throughout, returning to…

Abstract

WHEN a structure is subjected to a recurrent cycle of loading a number of different types of deformation may be set up. The structure may remain elastic throughout, returning to its original configuration at the end of each cycle. It may shake down to an elastic configuration which differs from the initial one, but which, once established, is the same at the end of each cycle. The structure may suffer inelastic deformation in each cycle of loading, with net value zero, so that again the configuration is the same at the end of each cycle: this condition is usually known as alternate plasticity and may lead to strain fatigue. Finally, the structure may suffer inelastic deformation in each cycle which has a non‐zero net value, so that the deformation changes progressively with each cycle of loading: this is known as incremental collapse.

Details

Aircraft Engineering and Aerospace Technology, vol. 28 no. 11
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 1 February 1995

Guy Jumarie

The theory of possibility (Zadeh, Sugeno) and the theory of relative information (Jumarie) both aim to deal with the meaning of information, but their mathematical frameworks are…

218

Abstract

The theory of possibility (Zadeh, Sugeno) and the theory of relative information (Jumarie) both aim to deal with the meaning of information, but their mathematical frameworks are quite different. In the first approach, possibility is described either by fuzziness (Zadeh) or by generalized measures (Sugeno), and in the second, possibility is obtained as the result of observing probability via an observation process with informational invariance. Shows that a combination of (classical) information theory with generalized maximum likelihood via geometric programming exhibits a link between relative information, fuzziness and possibility. Some consequences are outlined.

Details

Kybernetes, vol. 24 no. 1
Type: Research Article
ISSN: 0368-492X

Keywords

1 – 10 of 217