The Experts below are selected from a list of 81114 Experts worldwide ranked by ideXlab platform
Raghuvir Singh - One of the best experts on this subject based on the ideXlab platform.
-
Role of surface roughness on corrosion and Fretting corrosion behaviour of commercially pure titanium in Ringer’s solution for bio-implant application
Applied Surface Science, 2017Co-Authors: Bose Sivakumar, Lokesh Chandra Pathak, Raghuvir SinghAbstract:Abstract Influence of roughness (ra) from 43 to 474 nm on corrosion and Fretting corrosion of commercially pure titanium (CpTi) was studied in the Ringer’s solution. The anodic polarization and electrochemical impedance spectroscopy (EIS) revealed the highest corrosion resistance of CpTi with ra 43 nm and correlated well with the surface energy (SE). The highest potential drop associated with the Fretting corrosion is observed for CpTi with ra 43 nm followed by 474 nm; this is found to correspond with the worn out area. The Fretting current density (iFretting) is several order higher than obtained during the potentiodynamic polarization (without Fretting) study. Fretting corrosion manifested by the drop in electrochemical potential is simulated with high accuracy using Fretting current density and an initial contact area. Fretting corrosion at an applied potential (+250 mV(SCE)) is produced much larger Fretting corrosion current density than during the open circuit potential (OCP).
-
Role of surface roughness on corrosion and Fretting corrosion behaviour of commercially pure titanium in Ringer's solution for bio-implant application
Applied Surface Science, 2017Co-Authors: Bose Sivakumar, Lokesh Chandra Pathak, Raghuvir SinghAbstract:Influence of roughness (r a ) from 43 to 474 nm on corrosion and Fretting corrosion of commercially pure titanium (CpTi) was studied in the Ringer's solution. The anodic polarization and electrochemical impedance spectroscopy (EIS) revealed the highest corrosion resistance of CpTi with r a 43 nm and correlated well with the surface energy (S E ). The highest potential drop associated with the Fretting corrosion is observed for CpTi with r a 43 nm followed by 474 nm; this is found to correspond with the worn out area. The Fretting current density (i Fretting ) is several order higher than obtained during the potentiodynamic polarization (without Fretting) study. Fretting corrosion manifested by the drop in electrochemical potential is simulated with high accuracy using Fretting current density and an initial contact area. Fretting corrosion at an applied potential (+250 mV (SCE) ) is produced much larger Fretting corrosion current density than during the open circuit potential (OCP).
Shirong Ge - One of the best experts on this subject based on the ideXlab platform.
-
Determination of Fretting parameters of hoisting rope in coalmine and Fretting-fatigue behavior of steel wires
Industrial Lubrication and Tribology, 2013Co-Authors: Dagang Wang, Dekun Zhang, Shirong GeAbstract:Purpose – The objective of this paper is to determine Fretting parameters of hoisting rope according to the hoisting parameters in coalmine and to explore the effect of contact load on Fretting-fatigue behavior of steel wires. Design/methodology/approach – Based on the mechanical model of hoisting rope in coalmine, the dynamic tension simulation of hoisting rope was performed. Static equations of hoisting rope under tension and torsion and theories of contact mechanics were applied to obtain Fretting parameters. Fretting-fatigue tests of steel wires at different contact loads were conducted using a Fretting-fatigue test rig. The Fretting regime, normalized tangential force and Fretting-fatigue life were studied. The morphologies of Fretting contact scars and fracture surfaces were observed by scanning electron microscopy and optical microscopy to examine wear and failure mechanisms. Findings – Dynamic tension changes from 0 to 30,900 N. In outer strand layer, contact loads between steel wires in certain w...
-
effect of displacement amplitude on Fretting fatigue behavior of hoisting rope wires in low cycle fatigue
Tribology International, 2012Co-Authors: Dekun Zhang, Dagang Wang, Shirong GeAbstract:Abstract The effect of displacement amplitude on Fretting fatigue behavior of steel wires in low cycle fatigue at two cyclic strain levels was investigated. Evolutions of normalized tangential force and morphologies of contact scars were investigated to examine the wear mechanisms. Fretting regime and Fretting fatigue life were explored. Acoustic emission technique was utilized to reveal wire failure mechanisms. The results show that an increase of displacement amplitude increases normalized tangential force but decreases the Fretting fatigue life. Fretting contact conditions are all mixed Fretting regimes. Fretting damage and crack nucleation and propagation accelerate with increasing displacement amplitude.
-
Fretting fatigue behavior of steel wires in low cycle fatigue
Materials & Design, 2011Co-Authors: Dekun Zhang, Dagang Wang, Shirong GeAbstract:Abstract The effect of strain amplitude on Fretting–fatigue behavior of steel wires in low cycle fatigue was investigated using a Fretting–fatigue test rig which was capable of applying a constant normal contact load. The Fretting regime was identified based on the shape of the hysteresis loop of tangential force versus displacement amplitude. The variations of the normalized tangential force with increasing cycle numbers and Fretting–fatigue lives at different strain amplitudes were explored. The morphologies of Fretting contact scars after Fretting–fatigue tests were observed by scanning electron microscopy and optical microscopy to examine the failure mechanisms of steel wires. The acoustic emission technique was used to characterize the Fretting–fatigue damage in the Fretting–fatigue test. The results show that the Fretting regimes are all located in mixed Fretting regimes at different strain amplitudes. The increase in strain amplitude increases the normalized tangential force and decreases the Fretting fatigue life. The abrasive wear, adhesive wear and fatigue wear are main wear mechanisms for all Fretting–fatigue tests at different strain amplitudes. The accumulative total acoustic emission events during Fretting–fatigue until fracture of the tensile steel wire decrease with increasing strain amplitude. An increase of the strain amplitude results in the accelerated crack nucleation and propagation and thereby the decreased life.
-
Effect of Fretting amplitudes on Fretting wear behavior of steel wires in coal mines
Mining Science and Technology (china), 2010Co-Authors: Yan Shen, Dekun Zhang, Shirong GeAbstract:Abstract Given that Fretting wear causes failure in steel wires, we carried out tangential Fretting wear tests of steel wires on a self-made Fretting wear test rig under contact loads of 9 and 29 N and Fretting amplitudes ranging from 5 to 180 μm. We observed morphologies of fretted steel wire surfaces on an S-3000N scanning electron microscope in order to analyze Fretting wear mechanisms. The results show that the Fretting regime of steel wires transforms from partial slip regime into mixed Fretting regime and gross slip regime with an increase in Fretting amplitudes under a given contact load. In partial slip regime, the friction coefficient has a relatively low value. Four stages can be defined in mixed Fretting and gross slip regimes. The Fretting wear of steel wires increases obviously with increases in Fretting amplitudes. Fretting scars present a typical morphology of annularity, showing slight damage in partial slip regime. However, wear clearly increases in mixed Fretting regime where wear mechanism is a combination of plastic deformation, abrasive wear and oxidative wear. In gross slip regime, more severe degradation is present than in the other regimes. The main Fretting wear mechanisms of steel wires are abrasive wear, surface fatigue and friction oxidation.
-
research on the fatigue and fracture behavior due to the Fretting wear of steel wire in hoisting rope
Wear, 2003Co-Authors: Dekun Zhang, Shirong Ge, Y H QiangAbstract:Hoisting steel rope is an important component of the winding equipment in coalmines. Fretting wear and its induced fatigue and fracture of wires have been the major failure modes of the hoisting ropes. In this paper, a series of experiments on the Fretting friction and wear of steel wires were performed on an elastic beam oscillation test rig. The worn wires after Fretting tests were put into fatigue test on the servo-fatigue test machine. The research results demonstrated that the Fretting wear depth of the steel wires increased with the increasing Fretting cycles and contact loads. The fatigue life of the steel wires with fretted damage was inverse proportional to the wear depth, and then to the Fretting cycles and contact loads. The Fretting wear and fatigue mechanisms were analyzed through SEM morphologies of Fretting wear scars and fracture sections. It was found that the wear mechanism of Fretting wire depended on the contact loads. For low contact loads, light scratch modes dominated the Fretting of wires. When contact loads increased, third body abrasion appeared on the worn surfaces.
Andrew W Batchelor - One of the best experts on this subject based on the ideXlab platform.
-
some considerations on the mitigation of Fretting damage by the application of surface modification technologies
Journal of Materials Processing Technology, 2000Co-Authors: Yong Qing Fu, Andrew W BatchelorAbstract:Fretting is a surface-degradation process due to mechanical and chemical attack by small-amplitude oscillatory movement between two contacting surfaces and it is intimately related to wear, corrosion and fatigue. The introduction of surface treatments or coatings is expected to be an effective strategy against Fretting damage. This paper discusses the application of several types of advanced surface-modification methods for the mitigation of Fretting damage, such as physical and chemical vapour deposition (PVD and CVD), ion implantation, laser treatment and plasma nitriding, etc. Some coatings are effective in the mitigation of the Fretting wear, whereas others are more effective under Fretting fatigue conditions. The effects of surface-modification methods on Fretting resistance are explained using Fretting maps. There are at least five different mechanisms in using surface-modification methods to increase Fretting resistance: (1) inducing a residual compressive stress; (2) decreasing the coefficient of friction; (3) increasing the surface hardness; (4) altering the surface chemistry; (5) increasing the surface roughness. Apart from this, the intrinsic properties of the coatings, such as their density and mechanical and chemical properties as well as the adhesion condition with the substrate, also significantly affect the performance of the coatings under Fretting conditions. Based on this rationale, a coating-selection method was proposed to select the most appropriate surface treatments or coatings to minimise the probability of Fretting damage. Selection of a process is guided primarily by identification of the Fretting failure modes, and the ability to adjust and obtain the required surface properties, with a balance between the precise control of the surface properties and the process cost.
Helmi M Attia - One of the best experts on this subject based on the ideXlab platform.
-
Fretting fatigue and wear damage of structural components in nuclear power stations fitness for service and life management perspective
Tribology International, 2006Co-Authors: Helmi M AttiaAbstract:Abstract Fretting fatigue and wear problems have major economical and safety impact on the nuclear industry. This keynote paper provides examples of the Fretting problems encountered in nuclear power stations and an overview of the methodologies used to assess their root cause, their potential effect on the integrity of structural components and the future damage projection for risk management. The limitations of existing models that are commonly used to predict Fretting wear rate are discussed. A system approach to the Fretting wear/fatigue problem allowed us to significantly improve the capability of predicting Fretting damage through the recognition of the problem nonlinearity, and the effect of self-induced changes. The application of linear elastic fracture mechanics principles for predicting the Fretting wear and Fretting fatigue strength is demonstrated. The paper underlines the critical roles of the following two factors. First, the validation of the above mentioned methodologies, through experimental investigation of the long-term Fretting wear and fatigue behavior of structural components under realistic operating conditions. Second, the qualification of in -situ measurements of Fretting wear damage using nondestructive evaluation NDE and inspection methods.
S K Seshadri - One of the best experts on this subject based on the ideXlab platform.
-
Fretting-corrosion mapping of CP-Ti in Ringer's solution
Wear, 2010Co-Authors: Satendra Kumar, Bathala Sivakumar, S. Ganesh Sundara Raman, T. S. N. Sankara Narayanan, S K SeshadriAbstract:Fretting corrosion is a complex phenomena and a variety of factors such as load, contact area, frequency, number of Fretting cycles, extent of damage of the fretted zone, trapping of debris between the contacting surfaces, corrosivity of the medium, etc., will determine the Fretting-corrosion behaviour. The present paper aims to develop a Fretting-corrosion map of commercially pure Ti (CP-Ti) based on its Fretting-corrosion behaviour in Ringer's solution under various combinations of load, frequency and number of Fretting cycles. Based on the Fretting-corrosion behaviour and restoration ability, a Fretting-corrosion map of CP-Ti in Ringer's solution is developed for the first time. The Fretting-corrosion map of CP-Ti in Ringer's solution enables identification of various regimes depending on the nature of predominant phenomenon for a given set of conditions. Since Fretting corrosion is the dominant phenomenon at lesser duration of Fretting at 5 and 10 Hz for a load of 3 and 5 N, the safer use of CP-Ti, particularly for hip and knee implants, is a major concern. © 2010 Elsevier B.V. All rights reserved.
-
Evaluation of Fretting corrosion behaviour of CP-Ti for orthopaedic implant applications
Tribology International, 2010Co-Authors: Satendra Kumar, S. Ganesh Sundara Raman, T. S. N. Sankara Narayanan, S K SeshadriAbstract:The Fretting corrosion behaviour of CP-Ti in Ringer's solution was studied as a function of normal load, frequency and number of Fretting cycles. The restoration ability of CP-Ti after the passive film is damaged due to Fretting and as a function of the on-time/off-time ratio (intermittent Fretting) was also evaluated. The change in free corrosion potential measured before the onset of Fretting, with the onset of Fretting, during Fretting and after the Fretting motion ceases, as a function of time, was used to evaluate the Fretting corrosion behaviour. The restoration ability of CP-Ti after the passive film is damaged was ascertained by performing regression analysis of the potential data measured during repassivation. The morphological features of the fretted zone were assessed using scanning electron microscopy. Energy dispersive X-ray analysis was performed at the centre and edge regions of the fretted zone to identify their chemical nature. The study reveals that the excellent corrosion resistance and biocompatibility of CP-Ti are nullified under Fretting conditions. Once the passive oxide layer is damaged due to Fretting, repassivation is not instantaneous. The significant time delay in reaching the steady state potential implies that CP-Ti remains active and susceptible for corrosion. The difficulty in the instantaneous formation of passive film after the Fretting induced damage of the passive film, dissolution of bare Ti from the damaged areas and the possible accumulation of the debris generated during Fretting in the surrounding tissues raises concern on the safer use of CP-Ti as an implant material. © 2009 Elsevier Ltd. All rights reserved.
