Study on micro-plastic behavior and tribological characteristics of granular materials in friction process

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Gang Wang ◽  
Wei Wang ◽  
Yi Zhang ◽  
Xu Zhang ◽  
Zhaowen Hu ◽  
...  
Keyword(s):  
Granular Materials ◽  
Design Methodology ◽  
Working Condition ◽  
Friction Pair ◽  
Particle Breakage ◽  
Plastic Behavior ◽  
Friction Process ◽  
Friction Characteristics ◽  
Content Type ◽  
Three Body

Purpose This paper aims to investigate the micro-plastic behavior of granular material in three-body friction interface and its effect on friction characteristics. Design/methodology/approach A numerical model of particle breakage in friction contact was constructed based on the discrete element method. The influence of friction pair working condition and internal bonding strength on the micro-plastic behavior of particulate matter was analyzed. A reciprocating linear tribometer was used to verify the simulation results. Findings The results show that when the granular materials are squeezed and sheared by the friction pair, a shear zone inclined to the left is gradually formed, which leads to particle breakage. The breakage of the particle leads to the reduction of load-bearing capacity and the increase of friction coefficient. Due to the differences in bond strength and friction pairs working conditions, the particle plastic behavior is divided into the following three states: elastic deformation, breakage and plastic rheology. Originality/value This study is helpful to understand the effect of the micro-plastic behavior of particles on the three-body friction characteristics.

Resistance to cast iron seizure determined by the technological condition of the surface layer

2015 ◽  
Vol 67 (1) ◽  
pp. 17-21
Author(s):  
Stanislaw Laber
Keyword(s):  
Surface Layer ◽  
Cast Iron ◽  
Design Methodology ◽  
Friction Pair ◽  
Ground Surface ◽  
Technological Condition ◽  
Bearing Surface ◽  
Content Type ◽  
The Moment ◽  
Surface Curve

Purpose – The aim of this study was to evaluate a surface layer of the condition resistance to seizure. The surface layer was shaped in the processing grinding and burnishing. Design/methodology/approach – The resistance to seizure tests were carried out on a test station specially designed by the author. It is possible to simultaneously test the same two pairs of pivot–pan kinematic pairs on this station. Moreover, the time, route and the temperature of the friction area were registered. The time of sliding group operation from the moment when a lubricant is no longer added to the friction pair to the moment the sliding group reaches the critical temperature T = 418 K (145°C) is taken as a seizure indicator. Findings – The structure and state of the surface layer have an influence on the seizure of the surface of cooperating elements. Greater resistance to the seizure of the burnished surface in comparison to the ground surface is associated with differences in the state of the surface layer. The burnished surface has a smaller surface roughness and a higher value of the bearing surface curve, and the compressive stress occurs more often in the surface layer. Originality/value – There have been no studies on the effects of burnishing machining and grinding of cast iron in resistance to seizure.

The problems of resistance to scuffing of heavily loaded lubricated friction joints with WC/C-coated parts

2014 ◽  
Vol 66 (3) ◽  
pp. 434-442 ◽  
Author(s):  
Remigiusz Michalczewski ◽  
Witold Piekoszewski ◽  
Waldemar Tuszynski ◽  
Marian Szczerek
Keyword(s):  
Design Methodology ◽  
Solid Lubricant ◽  
Vapour Deposition ◽  
Friction Pair ◽  
Low Friction ◽  
Friction Zone ◽  
Content Type ◽  
Steel Coating ◽  
Uncoated Steel ◽  
Practical Implications

Purpose – The purpose of this paper was to explore the mechanisms of scuffing propagation of heavily loaded lubricated friction pair elements coated with low-friction WC/C coating for various material combinations. Design/methodology/approach – The investigations were performed for low-friction coatings WC/C (a-C:H:W) deposited by the reactive sputtering physical vapour deposition (PVD) process. Experiments were carried out using a four-ball tester with continuously increasing loads. Tests were conducted for the following four material combinations: steel/steel tribosystem (all balls uncoated); steel/coating tribosystem (one upper ball uncoated/three lower balls WC/C-coated); coating/steel tribosystem (one upper ball WC/C-coated/three lower balls uncoated); and coating/coating tribosystem (all balls WC/C-coated). Findings – The better scuffing resistance is achieved by coating only one element (coating/steel tribosystem) than all elements (coating/coating tribosystem). The description of scuffing propagation for all investigated tribosystems was done. The high scuffing resistance of the coating/steel tribosystem resulted from reducing the adhesion between rubbing surfaces due to low chemical affinity (similarities) between the steel and the coating material and the presence of solid lubricant in the friction zone. Practical implications – In all cases, when a coating is applied, an increase in scuffing resistance is observed. However, it is better to coat only one element than all. Furthermore, the scuffing resistance for the coating/steel tribosystem is significantly higher than for the steel/coating tribosystem. Originality/value – The main value of this paper is description of scuffing propagation and revealing the new aspects in application of low-friction WC/C coating for heavily loaded lubricated friction pair elements. The overlapping ratio has been defined as an important factor influencing the scuffing resistance of the coated tribosystems.

Effect of the bionic morphologies on bio-tribological properties of surface-modified layers on Ti6Al4V with Ni+/N+ implantation

2018 ◽  
Vol 70 (2) ◽  
pp. 325-330 ◽  
Author(s):  
Yuan Wang
Keyword(s):  
Tribological Properties ◽  
Design Methodology ◽  
Friction Pair ◽  
Artificial Saliva ◽  
Ti6al4v Alloy ◽  
Implantation Technique ◽  
Content Type ◽  
X Ray ◽  
Tribological Tests ◽  
Surface Modified

Purpose The main purpose of this study is to enhance bio-tribological properties of Ti6Al4V and the surface-modified layers of Ni+/N+-implanted Ti6Al4V alloy, bionic texturing was done on Ti6Al4V surface. Design/methodology/approach The phase compositions and nano-hardness of the surface-modified layers of the samples have been analyzed by X-ray diffractometer and Nano Indenter, respectively. This paper has conducted bio-tribological tests under artificial saliva, sodium hyalurate and sodium hyalurate +γ-globulin by micro tribology multifunction tribometer, with ZrO2 ball/modified layer as the friction pair. S-3000N scanning electron microscope has been used to analyze the morphology of the surface-modified layers and scratches of the ones after the bio-tribological tests. Findings The results show that the surface-modified layers were mainly composed of Ti2Ni and Ti2N. Moreover, bionic texturing can obviously increase the contents of Ti2Ni and Ti2N that were formed on the surface of Ni+/N+-implanted Ti6Al4V alloy, and enhance the nano-hardness of the surface-modified layers. It could also reduce the friction coefficients of the surface-modified layers, and render the modified layers more wear-resistant. Originality/value The surface bio-tribological properties of Ti6Al4V have been enhanced by ion implantation technique and bionic texturing in this paper; this provided a new method for the research of related fields.

Modification of working conditions for a friction pair with an additive added to engine oil during operation

2014 ◽  
Vol 66 (4) ◽  
pp. 560-567
Author(s):  
Alicja Laber
Keyword(s):  
Boundary Layer ◽  
Surface Layer ◽  
Friction Force ◽  
Tribological Properties ◽  
Friction Pair ◽  
Engine Oil ◽  
Friction Process ◽  
Content Type ◽  
Increasing Load ◽  
Wear Index

Purpose – The purpose of this paper is to present the results of research into using an additive to SAE 15W/40 engine oil during operation and its influence on lubricating properties (normalised tests) on weld point Pz, non-seizure load Pn, load wear index Ih and on seizure load Pt. The friction pair consisted of a group of four balls and the tested lubricant. Moreover, the author tested the influence of an additive to engine oil (non-normalised tests) on tribological properties, including friction force, wear and the temperature of friction area for the C45 steel/210Cr12 steel friction joint. She also determined the influence of an additive to engine oil on the formation of the operating surface layer. The research results helped to build the model of the boundary layer that was formed as a result of adding an additive to engine oil. Design/methodology/approach – The lubricant properties of engine oil and engine oil to which an additive was added during operation were determined according to PN-76/C-04147. The following are the indexes of lubricant properties: weld point Pz, load wear index Ih, non-seizure load Pn, seizure load and average scar diameter. The Pz, Pn and Ih indexes were determined at abruptly increasing load to the moment of welding of the friction pair. The Pt index was determined at the increasing load of the friction pair from 0 to 800 daN at the speed of 408.8 N/s. The tests of tribological properties (friction force, wear and the temperature of friction area) were conducted for the C45/210 Cr12 friction pair in the presence of a lubricant and a lubricant with an additive. Findings – The modification of SAE 15W/40 engine oil with the additive added during operation resulted in improved indexes of lubricant properties Pz, Pn, Ih and Pt and average scar diameter. The boundary layer for the modified oil breaks after a longer time and at lesser friction force. The modification of the engine oil reduced the wear of the friction pair. After the friction process, element composition in the surface layer of the wear trace and its distribution were determined in relation to applied lubricants. A significant amount of sulphur, phosphorus and oxygen, as well as an insignificant amount of copper, was observed in the wear trace after the friction process in the presence of the lubricant medium. The distribution of elements in the wear trace when the engine oil with the additive was used is steady in the wear trace and outside it. Some sulphur, phosphorus and chlorine were found in the wear trace. Originality/value – The results of tests on tribological properties (non-normalised tests) confirmed the positive affect of the additive to engine oil on lubricant properties (normalised tests). The modification of the engine oil caused reduced friction force and the reduced wear of the friction pair. The reduction of friction force and wear was the result of the formation of the surface of a greater amplitude density of unevenness tops in the friction process. Moreover, the operating surface layer, created in the friction process when the additive was added to the engine oil, had greater load participation at 50 per cent C. This operational surface layer improved tribological properties, i.e. it reduced value of friction force and wear. The test results were used to build a model of the boundary layer created as a result of the additive added to engine oil.

Research on lubrication and friction characteristics of oil seal with isosceles triangle texture and micro concave lip

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fuying Zhang ◽  
Yuanhao Zhang
Keyword(s):  
Design Methodology ◽  
Reynolds Equation ◽  
Elastohydrodynamic Lubrication ◽  
Isosceles Triangle ◽  
Optimal Combination ◽  
Friction Characteristics ◽  
Content Type ◽  
Theoretical Support ◽  
Texture Parameters ◽  
Lubrication Characteristics

Purpose This paper aims to study the effect of isosceles triangle micro concave texture with different parameters on the performance of oil seal to obtain a reasonable combination of parameters. Design/methodology/approach Based on the theory of elastohydrodynamic lubrication, a numerical model is established by coupling the texture parameters of isosceles triangle with concave lip with the two-dimensional average Reynolds equation considering surface roughness. Findings The results show that there is an optimal combination of parameters to improve the performance of the oil seal. When hp = 5µm-6.5 µm, a = 110°−130°, O = 1.4, C = 1.6 mm-2.2 mm, the oil seal with isosceles triangle micro concave texture can show good lubrication characteristics, friction characteristics and sealing ability. Originality/value The model provides a new idea for the design of new oil seal products and provides a theoretical support for the application of surface texture technology in the sealing field in the future.

Microstructure in the joining zone during the friction welding of the two dissimilar steels

2018 ◽  
Vol 70 (2) ◽  
pp. 401-407
Author(s):  
Nada Ratković ◽  
Vukic Lazić ◽  
Dušan Arsić ◽  
Ružica R. Nikolić ◽  
Radica Prokić Cvetković ◽  
...  
Keyword(s):  
Friction Welding ◽  
Design Methodology ◽  
Experimental Testing ◽  
Austenite Grain Size ◽  
Friction Process ◽  
Content Type ◽  
Fine Grain ◽  
Austenite Grain ◽  
Dissimilar Steels ◽  
High Degree

Purpose The purpose of this paper is to point out the possibilities for friction welding of dissimilar steels which are used in various industries. In addition, friction welding is a welding method that is applied for executing the very responsible joints. This research is focused on friction and tribological processes in the friction plane of the two pieces during the welding. Design/methodology/approach The present study research has been conducted based on the experimental testing of cylindrical specimens and results are analyzed. Findings The austenite grain size is affected by several factors through the friction process phase and the compacting phase during the welding. The very fine grain is the consequence of the high degree of the plastic deformation of the near-the-contact layers even in the friction phase. The viscous layer, which is formed during the stable friction phase, is the area where the moving of matter occurs according to a very complex mechanism. Originality/value The paper contains useful results from the area of conventional friction welding of dissimilar steels and it can be very useful to researchers and engineers who deal with similar problems.

scholarly journals Vulnerable adults in police custody

2019 ◽  
Vol 22 (1) ◽  
pp. 5-8
Author(s):  
Ian Cummins
Keyword(s):  
Design Methodology ◽  
Research Literature ◽  
Police Custody ◽  
England And Wales ◽  
Content Type ◽  
Increased Risk ◽  
Vulnerable Adults

Purpose The purpose of this paper is to discuss the recent National Appropriate Adult Network (NAAN) report on the role of the appropriate adult. Design/methodology/approach This paper is based on the NAAN report and a review of relevant policy and research literature. Findings There to Help 2 highlights that there are still significant gaps in the provision of appropriate adult schemes across England and Wales. These gaps potentially place vulnerable adults at increased risk. Originality/value This paper is a review of recent research.

Co-workers’ perceptions of and reactions to employee’s involuntary demotion

2019 ◽  
Vol 41 (4) ◽  
pp. 740-757 ◽  
Author(s):  
Sophie Hennekam ◽  
Subramaniam Ananthram ◽  
Steve McKenna
Keyword(s):  
Design Methodology ◽  
Emotional Responses ◽  
Emotional Reaction ◽  
Content Type ◽  
Informational Justice ◽  
Behavioural Responses ◽  
Behavioural Reaction ◽  
Three Stages ◽  
Depth Interviews ◽  
The Way

Purpose The purpose of this paper is to investigate how individuals perceive and react to the involuntary demotion of a co-worker in their organisation. Design/methodology/approach The authors draw on 46 semi-structured in-depth interviews (23 dyads) with co-workers of demoted individuals. Findings The findings suggest that an individual’s observation of the demotion of a co-worker has three stages: their perception of fairness, their emotional reaction and their behavioural reaction. The perception of fairness concerned issues of distributive, procedural, interpersonal and informational justice. The emotional responses identified were feelings of disappointment/disillusion, uncertainty, vulnerability and anger. Finally, the behavioural reactions triggered by their emotional responses included expressions of voice, loyalty, exit and adaptation. Originality/value Perceptions of (in)justice perpetrated on others stimulate emotional and behavioural responses, which impacts organisational functioning. Managers should therefore pay attention to the way a demotion is perceived, not only by those directly concerned, but also by co-workers as observers.

Consumer value creation through WhatsApp use

2019 ◽  
Vol 32 (4) ◽  
pp. 455-471
Author(s):  
Jorge Cruz-Cárdenas ◽  
Jorge Guadalupe-Lanas ◽  
Ekaterina Zabelina ◽  
Andrés Palacio-Fierro ◽  
Margarita Velín-Fárez ◽  
...  
Keyword(s):  
Latin American ◽  
Value Creation ◽  
Emotional Support ◽  
Design Methodology ◽  
Instant Messaging ◽  
Role Performance ◽  
Content Type ◽  
Consumer Value ◽  
Depth Interviews ◽  
Practical Implications

Purpose The purpose of this paper is to understand in-depth how consumers create value in their lives using WhatsApp, the leading mobile instant messaging (MIM) application. Design/methodology/approach The study adopts the perspective of customer-dominant logic (CDL) and uses a qualitative multimethod design involving 3 focus groups and 25 subsequent in-depth interviews. The research setting was Ecuador, a Latin American country. Findings Analysis and interpretation of the participants’ stories made it possible to identify and understand the creation of four types of value: maintaining and strengthening relationships; improving role performance; emotional support; and entertainment and fun. In addition, the present study proposes a conceptual model of consumer value creation as it applies to MIM. Practical implications Understanding the way consumers create value in their lives using MIM is important not only for organizations that offer MIM applications, but also for those companies that develop other applications for mobile phones or for those who wish to use MIM as an electronic word-of-mouth vehicle. Originality/value The current study is one of the first to address the topic of consumer behavior in the use of technologies from the perspective of CDL; this perspective enables an integrated qualitative vision of value creation in which the consumer is the protagonist.

scholarly journals Advantages and potential challenges of data management in e-maintenance

2019 ◽  
Vol 25 (3) ◽  
pp. 378-396 ◽  
Author(s):  
Arian Razmi-Farooji ◽  
Hanna Kropsu-Vehkaperä ◽  
Janne Härkönen ◽  
Harri Haapasalo
Keyword(s):  
Data Management ◽  
Design Methodology ◽  
Management Practices ◽  
Future Research ◽  
Conceptual Approach ◽  
Content Type ◽  
Different Types ◽  
Maintenance Systems ◽  
Industry Leader ◽  
Practical Implications

Purpose The purpose of this paper is twofold: first, to understand data management challenges in e-maintenance systems from a holistically viewpoint through summarizing the earlier scattered research in the field, and second, to present a conceptual approach for addressing these challenges in practice. Design/methodology/approach The study is realized as a combination of a literature review and by the means of analyzing the practices on an industry leader in manufacturing and maintenance services. Findings This research provides a general understanding over data management challenges in e-maintenance and summarizes their associated proposed solutions. In addition, this paper lists and exemplifies different types and sources of data which can be collected in e-maintenance, across different organizational levels. Analyzing the data management practices of an e-maintenance industry leader provides a conceptual approach to address identified challenges in practice. Research limitations/implications Since this paper is based on studying the practices of a single company, it might be limited to generalize the results. Future research topics can focus on each of mentioned data management challenges and also validate the applicability of presented model in other companies and industries. Practical implications Understanding the e-maintenance-related challenges helps maintenance managers and other involved stakeholders in e-maintenance systems to better solve the challenges. Originality/value The so-far literature on e-maintenance has been studied with narrow focus to data and data management in e-maintenance appears as one of the less studied topics in the literature. This research paper contributes to e-maintenance by highlighting the deficiencies of the discussion surrounding the perspectives of data management in e-maintenance by studying all common data management challenges and listing different types of data which need to be acquired in e-maintenance systems.

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