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Article
Publication date: 21 October 2022

Longxiao Zhang and Ting Xie

The purpose of this paper is to explore the geometric parameter difference of the terrace-like structural transfer film under different working parameters [pressure and velocity…

111

Abstract

Purpose

The purpose of this paper is to explore the geometric parameter difference of the terrace-like structural transfer film under different working parameters [pressure and velocity (PV) values] and filled particle types (three fillers: SiO2, TiO2 and ZnO), and find the geometric parameter related to the wear of polytetrafluoroethylene (PTFE)-based composites.

Design/methodology/approach

PTFE composites were filled with SiO2, TiO2 and ZnO particles, and the morphology parameter of the PTFE composite transfer film under different PV values obtained from the rotary reciprocating pin-on-disk frictional tester was quantified by using a three-dimensional laser scanning microscope.

Findings

The results showed that the effective layer coverage rate and effective thickness of the transfer film had a good relationship with the wear of the three PTFE composites. On the whole, increasing the speed or load was helpful to increase the effective thickness of the three PTFE composite transfer films, but reduced the effective layer coverage rate. The greater the effective layer coverage rate and effective thickness of the transfer film, the better the wear resistance of the PTFE composites in the entire speed and load range.

Originality/value

This work will promote further understanding of the transfer film and lay a foundation for realizing its morphology regulation and improving the wear of the PTFE composites.

Details

Industrial Lubrication and Tribology, vol. 75 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 25 September 2019

Ting Xie, Junjie Lai and Huaping Yang

This paper aims to simulate the effect of counterface roughness on the friction transfer and wear of the polymer material sliding against steel.

155

Abstract

Purpose

This paper aims to simulate the effect of counterface roughness on the friction transfer and wear of the polymer material sliding against steel.

Design/methodology/approach

The dynamic process of friction transfer and wear of polytetrafluoroethylene (PTFE) sliding against steel 45 was simulated by the software of particle flow code in two dimensions and a discrete element method. The effect of the counterface roughness was considered in the simulation. The definitions of the transferred particle and worn particle were given.

Findings

The simulation results showed that a transferred particle layer was formed on the surface of steel 45 during friction. The wear rate of PTFE can be effectively reduced by the formation of the transferred particle layer. The formation and stability of this particle layer is certainly affected by the counterface roughness (Rz). In this paper, the transferred particle numbers increased with Rz increase. And so did the worn particle numbers. However, there was little effect of Rz on the wear rate of PTFE.

Originality/value

The dynamic process of the friction transfer and wear of the PTFE/ steel 45 friction pair was reproduced at the micro-level. Then, the transfer and wear were quantitatively exhibited. The relations between the transfer or wear and counterface roughness was simulated and discussed. It will be meaningful for the optimization and effective control of friction and wear of polymer/metal sliding system.

Details

Industrial Lubrication and Tribology, vol. 71 no. 9
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 7 November 2024

Longxiao Zhang, Binghe Wang, Kun Chen, Shouren Wang, Gaoqi Wang, Peng Wang and Ting Xie

The purpose of this paper is to fill low content of silica to improve the wear resistance of graphite/polytetrafluoroethylene (PTFE) composites, and to discuss the effect of low…

15

Abstract

Purpose

The purpose of this paper is to fill low content of silica to improve the wear resistance of graphite/polytetrafluoroethylene (PTFE) composites, and to discuss the effect of low content of silica on the morphology of terrace-like transfer film.

Design/methodology/approach

The tribological properties of silica/graphite/PTFE composites were tested by rotating pin-on-disk friction and wear tester, and the morphology of terrace-like transfer film was observed by 3D laser scanning microscope and quantitatively analyzed through the multi-Gaussian function linear combination model.

Findings

The results showed that adding 3 wt.% silica in graphite/PTFE composites can reduce the wear rate by 87%. More importantly, the morphology of terrace-like transfer film changed significantly after filling a small amount of silica, including the increase of the number of layers and the coverage rate of transfer film.

Originality/value

This work is of great significance for further understanding the transfer film and achieving its morphology control to optimize the wear of high performance PTFE composites.

Details

Industrial Lubrication and Tribology, vol. 76 no. 10
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 16 October 2018

Guotao Zhang, Yanguo Yin, Ting Xie, Dan Li, Ming Xu and Congmin Li

This paper aims to obtain high mechanical and good tribological properties of epoxy resin-based coatings under dry friction conditions.

221

Abstract

Purpose

This paper aims to obtain high mechanical and good tribological properties of epoxy resin-based coatings under dry friction conditions.

Design/methodology/approach

Bonded solid lubricant coatings containing Kevlar fibres were prepared by a spraying method. The friction and wear properties of the coatings were experimentally investigated with a face-to-face tribometre under dry friction conditions. Scanning electron microscopy, energy dispersive X-ray spectroscopy and 3D laser scanning technologies were used to characterise the tribological properties. The action mechanism of the Kevlar fibres on a solid lubricant transfer film was also analysed.

Findings

Adding Kevlar fibres can significantly improve the wear resistance of the coatings. When the Kevlar fibre content increases, the tribological properties of the coatings improve and then worsen. Superior properties are obtained with 0.03 g of Kevlar fibres. Appropriately increasing the load or speed is beneficial to the removal of the outer epoxy resin and the formation of a lubricant film. During friction, the solid lubricants wrapped in the epoxy resin accumulate on the surface to form a transfer film that shows a good self-lubricating performance. In the later friction stage, fatigue cracks occur on the solid lubricant film but cannot connect to one another because of the high wear resistance and the entanglement of the rod-like Kevlar fibres. Thus, no large-area film falls from the matrix, thereby ensuring the long-term functioning of solid lubricant coatings.

Originality/value

Epoxy resin-based solid lubricant coatings modified by Kevlar fibres were prepared, and their friction and wear properties were investigated. Their tribological mechanisms were also proposed. This work provided a basis for the analysis of the tribological properties and design of bonded solid lubricant coatings containing Kevlar fibres.

Details

Industrial Lubrication and Tribology, vol. 70 no. 9
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 13 July 2021

Chen Li, Heng Wen, Kun Chen, Longxiao Zhang, Ting Xie, Yaru Shi and Junlong Zhang

This paper aims to develop a Mini-Tribometer for in-situ observation of subsurface.

131

Abstract

Purpose

This paper aims to develop a Mini-Tribometer for in-situ observation of subsurface.

Design/methodology/approach

To observe the change of the microstructure during wear in real time, an in-situ observation mini-tribometer was developed according to the requirements of the basic frictional experiments and carried out the verification experiments.

Findings

The subsurface images and the tribological data obtained from the mini-tribometer clearly show that the graphite in the matrix moves to the surface and takes part in lubrication mainly in the form of extrusion and peeling off, and the migration of graphite in the copper-based composite to the frictional interface to act as lubricant and to result in the decrease of the friction coefficient. The experimental results of the developed tribometer are accurate, which can provide important references for further research on the wear mechanism of materials.

Originality/value

The developed in-situ observation mini-tribometer can be used to observe the dynamic wear mechanism of the frictional pairs, which is very important for optimization of material design and tribological performances.

Details

Industrial Lubrication and Tribology, vol. 73 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 16 December 2021

Xin Wang and Ting-Qiang Xie

Cavitation erosion has always been a common technical problem in a hydraulic discharging structure. This paper aims to investigate the cavitation erosion behavior of hydraulic…

268

Abstract

Purpose

Cavitation erosion has always been a common technical problem in a hydraulic discharging structure. This paper aims to investigate the cavitation erosion behavior of hydraulic concrete under high-speed flow.

Design/methodology/approach

A high-speed and high-pressure venturi cavitation erosion generator was used to simulate the strong cavitation. The characteristics of hydrodynamic loads of cavitation bubble collapse zone, the failure characteristics and the erosion development process of concrete were investigated. The main influencing factors of cavitation erosion were discussed.

Findings

The collapse of the cavitation bubble group produced a high frequency, continuous and unsteady pulse load on the wall of concrete, which was more likely to cause fatigue failure of concrete materials. The cavitation action position and the main frequency of impact load were greatly affected by the downstream pressure. A power exponential relationship between cavitation load, cavitation erosion and flow speed was observed. With the increase of concrete strength, the degree of damage of cavitation erosion was approximately linearly reduced.

Originality/value

After cavitation erosion, a skeleton structure was formed by the accumulation of granular particles, and the relatively independent bulk structure of the surface differed from the flake structure formed after abrasion.

Details

Anti-Corrosion Methods and Materials, vol. 69 no. 1
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 10 February 2021

H.T. Xie

The purpose of this paper is to describe and compare the attributes of community dwelling adults with serious mental health illnesses in the USA and Singapore in terms of…

140

Abstract

Purpose

The purpose of this paper is to describe and compare the attributes of community dwelling adults with serious mental health illnesses in the USA and Singapore in terms of perception of mental health recovery and its correlates, namely, strengths self-efficacy, resourcefulness and stigma experience.

Design/methodology/approach

A convenience sample of 100 participants from each country participated in the study by completing self-administered questionnaires.

Findings

The results showed high overall scores in mental health recovery, strengths self-efficacy and resourcefulness in both countries with only a statistically significant difference between both countries in mental health recovery. Participants in both countries also experienced stigma.

Research limitations/implications

The study not only enhanced the focus on mental health and its correlates but also suggested the need for efforts to de-stigmatize mental health conditions which could impact on mental health recovery.

Originality/value

This paper is original and adds on to the knowledge base on mental health recovery and its correlates through the unique opportunity to review information from both countries.

Details

Mental Health Review Journal, vol. 26 no. 1
Type: Research Article
ISSN: 1361-9322

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Article
Publication date: 1 August 2023

Peng Xie, Hongwei Du, Jiming Wu and Ting Chen

In prior literature, online endorsement system allowing the users to “like” or “dislike” shared information is found very useful in information filtering and trust elicitation in…

1163

Abstract

Purpose

In prior literature, online endorsement system allowing the users to “like” or “dislike” shared information is found very useful in information filtering and trust elicitation in most social networks. This paper shows that such systems could fail in the context of investment communities due to several psychological biases.

Design/methodology/approach

This study develops a series of regression analyses to model the “like”/“dislike” voting process and whether or not such endorsement distinguishes between valuable information and noise. Trading simulations are also used to validate the practical implications of the findings.

Findings

The main findings of this research are twofold: (1) in the context of investment communities, online endorsement system fails to signify value-relevant information and (2) bullish information and “wisdom over the past event” information receive more “likes” and fewer “dislikes” on average, but they underperform in stock market price discovery.

Originality/value

This study demonstrates that biased endorsement may lead to the failure of the online endorsement system as information gatekeeper in investment communities. Two underlying mechanisms are proposed and tested. This study opens up new research opportunities to investigate the causes of biased endorsement in online environment and motivates the development of alternative information filtering systems.

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Article
Publication date: 3 August 2020

Chong Liu, Wanli Xie, Tongfei Lao, Yu-ting Yao and Jun Zhang

Gross domestic product (GDP) is an important indicator to measure a country's economic development. If the future development trend of a country's GDP can be accurately predicted…

352

Abstract

Purpose

Gross domestic product (GDP) is an important indicator to measure a country's economic development. If the future development trend of a country's GDP can be accurately predicted, it will have a positive effect on the formulation and implementation of the country's future economic development policies. In order to explore the future development trend of China's GDP, the purpose of this paper is to establish a new grey forecasting model with time power term to forecast GDP.

Design/methodology/approach

Firstly, the shortcomings of the traditional grey prediction model with time power term are found out through analysis, and then the generalized grey prediction model with time power term is established (abbreviated as PTGM (1,1, α) model). Secondly, the PTGM (1,1, α) model is improved by linear interpolation method, and the optimized PTGM (1,1, α) model is established (abbreviated as OPTGM (1,1, α) model), and the parameters of the OPTGM (1,1, α) model are solved by the quantum genetic algorithm. Thirdly, the advantage of the OPTGM (1,1, α) model over the traditional grey models is illustrated by two real cases. Finally the OPTGM (1,1, α) model is used to predict China's GDP from 2020 to 2029.

Findings

The OPTGM (1,1, α) model is more suitable for predicting China's GDP than other grey prediction models.

Originality/value

A new grey prediction model with time power term is proposed.

Details

Grey Systems: Theory and Application, vol. 11 no. 3
Type: Research Article
ISSN: 2043-9377

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Article
Publication date: 1 August 2006

Jun Onishi and Ryan E. Bliss

Despite contrary evidence, much management research treats Asians as culturally homogeneous. This study seeks to explore how managers from four Asian nations differ in conflict…

3546

Abstract

Purpose

Despite contrary evidence, much management research treats Asians as culturally homogeneous. This study seeks to explore how managers from four Asian nations differ in conflict management and whether observed differences are linked to cultural attitudes.

Design/methodology/approach

A questionnaire assessed conflict management practices and cultural attitudes of managers from four nations with considerable historical, geographical, and economic differences. ANOVA and ANCOVA were used to test hypotheses about groups differences in preference for three conflict management styles – competing integrating, and avoiding – controlling for differences in demographics and cultural attitudes.

Findings

Statistically significant differences were found on all three of the conflict management styles, although the hypotheses were only partly supported. Controlling for differences in demographics and cultural attitudes had little impact on the main findings. Some similarities among the nationalities were found: “integrating” was the most preferred style, and showed the least variation, among the groups. However, there was less similarity among the nationalities regarding “competing” and “avoiding”.

Research limitations/implications

Since the hypotheses – based largely on national culture differences among the nationalities – were only partly supported, future research should attempt to identify variables that better explain differences among nationalities in conflict management style.

Practical implications

The information on conflict management style preferences in these four nations will be valuable to those wishing to do business there. Further, refuting the common assumption of cultural homogeneity among Asians will better prepare Westerners for doing business elsewhere in Asia.

Originality/value

This paper demonstrates that national differences in conflict management style were not based on demographic differences in the sample or differences in cultural attitudes.

Details

International Journal of Conflict Management, vol. 17 no. 3
Type: Research Article
ISSN: 1044-4068

Keywords

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