Crystalline texture evolution, control of the tribocorrosion behavior, and significant enhancement of the abrasion properties of a Ni-P nanocomposite coating enhanced by zirconia nanoparticles

This paper describes an investigation of the effect of ZrO2 nanoparticles on the abrasive properties,crystalline texture developments,and tribocorrosion behavior of Ni-P nanostructured coatings.In the investigation,Ni-P and Ni-P-ZrO2 nanostructured coatings are deposited on St52 steel via the electroless method.Transmission electron microscopy(TEM),field emission scanning electron microscopy(FE-SEM),X-ray diffraction(XRD),energy dispersive spectroscopy(EDS),cyclic-static polarization tests in 3.5wt%NaCl solution,the tribocorrosion test(by back-and-forth wear in electrochemical cell),and the microhardness test using the Vickers method were performed to characterize and analyze the deposited coatings.The results of this study showed that the addition of ZrO2 nanoparticles to the Ni-P electroless bath produced the following:a sharp increase in wear and hardness resistance,the change of the wear mechanism from sheet to adhesive mode,the reduction of pitting corrosion resistance,significant reduction in the tribocorrosion protective properties,change in the preferred orientation of the crystalline texture coating from(111)to(200),increase in the sedimentation rate during the deposit process,and a sharp increase in the thickness of the Ni-P nanostructured coatings.

Corrosion and tribocorrosion resistance of MAO-based composite coating on AZ31 magnesium alloy

In this paper, a multi-functional composite coating with low friction coefficient, high wear resistance and excellent tribocorrosion resistance is fabricated on AZ31 Mg alloys by micro-arc oxidation and spray-coating methods. The microstructure, and composition of the coating are characterized by SEM, EDS, XRD, and FT-IR. Potentiodynamic polarization and EIS tests are conducted to evaluate the corrosion resistance of the composite coating. The tribocorrosion property is also studied using pin-on-disk tribometer in 3.5 wt.% Na Cl solution. It is found that the composite coating possesses better long-term corrosion resistance than the single MAO coating. The tribocorrosion tests prove that the composite coating exhibits much better wear and tribocorrosion resistance than the single MAO coating and can protect the substrate from corrosion under a sliding condition.

Impact–sliding fretting tribocorrosion behavior of 316L stainless steel in solution with different halide concentrations

Impact–sliding caused by random vibrations between tubes and supports can affect the operation of heat exchangers.In addition,a corrosive environment can cause damage,accelerating the synergism of corrosion and wear.Therefore,the focus of this work was the impact–sliding fretting tribocorrosion behavior of 316L heat exchanger tubes at different halide concentrations.A device system incorporating the in situ electrochemical measurements of impact–sliding fretting corrosion wear was constructed,and experiments on 316L heat exchanger tubes in sodium chloride(NaCl)solution with different concentrations(0.0,0.1,0.5,1.0,3.5,and 5.0 wt%)were carried out.The synergism between wear and corrosion was also calculated and analyzed.The wear and damage mechanisms were elucidated by correlating the corrosion–wear synergism,morphologies,and material loss rates.The results indicated that the stable wear stage occurred at approximately 9–12 h,after which the corrosion current increased with the expansion of the wear area.As the halide concentration increased,the scale of damage on the wear scars gradually decreased,changing from being dominated by cracks,delaminations,and grooves to being dominated by scratches,microgrooves,and holes.There was an obvious positive synergism between wear and corrosion.The material loss was dominated by pure mechanical wear and wear enhanced by corrosion,but corrosion enhanced by wear contributed more than tangential sliding fretting corrosion.The total mass loss increased gradually in the range of 0.0–0.5 wt%and decreased in the range of 0.5–5.0 wt%.Large-scale damage enhanced by corrosivity and small-scale damage reduced by lubricity dominated the material loss at low and high concentrations,respectively.

Tribocorrosion behavior in artificial seawater and anti-microbiologically influenced corrosion properties of TiSiN-Cu coating on F690 steel

The TiSiN-Cu nanocomposite coating was deposited on F690 steel substrate by arc ion plating. The structure and composition, tribocorrosion behavior and anti-microbiologically influenced corrosion(MIC)properties of TiSiN-Cu coating were investigated. The results show that the TiSiN-Cu coating has unique nanocomposite structures. The results of tribocorrosion show that the potential and current change of F690 steel and TiSiN-Cu coatings tend to be opposite. The reason is that the F690 steel is non-passivated metal and the TiSiN-Cu coating has passivation phenomenon. The TiSiN-Cu coating possesses excellent tribocorrosion resistance. Cu ion released from TiSiN-Cu coating can effectively inhibit the corrosion caused by SRB.

Tribocorrosion behavior of nickel-aluminium bronze sliding against alumina under the lubrication by seawater with different halide concentrations

The tribocorrosion failure mechanism of nickel-aluminium bronze(NAB) in different halide concentrations of seawater was studied using a pin-on-disc tribometer that was modified to conduct in-situ electrochemical detection during the sliding process. It has been reported that high-halide-concentration seawater provided a good lubricating effect, and thus reduced the coefficient of friction and wear rate of NAB during the tribocorrosion process. However, the existence of halide ions corroded the passive film and hindered the repassivation of the damaged areas in the wear track, resulting in an increased corrosion rate. In addition, the morphology of the wear scar revealed the occurrence of abrasive, delamination, and adhesive wear of NAB in seawater. For the whole range of halide concentration values, a positive synergy between wear and corrosion was proven, and the quantification of this synergy was discussed in detail. The results show that the corrosionwear synergism was decreased with increasing halide concentration in seawater, and the corrosion-induced wear was dominant in the two synergistic components.

Tribocorrosion Behavior of 304 Stainless Steel in 0.5 mol/L Sulfuric Acid

The tribocorrosion behavior of 304 stainless steel was studied through comparing the damage behavior of 304 stainless steel in dilute sulfuric acid to that in distilled water by a reciprocating tribotester. The re-passivation behavior, the surface and sectional morphological features, as well as the change of microhardness of samples were studied, and the tribocorrosion mechanism was also discussed. The experimental results reveal that the damage of stainless steel in dilute sulfuric acid was caused by the steel＇s mechanical removal and electrochemical dissolution. The wear mechanism of stainless steel is abrasive wear, which mainly consists of micro-cutting and peeling. The synergetic action between corrosion and wear is notable. The corrosive environment leads to the embrittlement of the surface layer, and the wear destroys the passivation film and causes galvanic corrosion.

Tailoring the microstructure,mechanical and tribocorrosion performance of (CrNbTiAlV)N_(x) high-entropy nitride films by controlling nitrogen flow

The(CrNbTiAlV)N_(x)high-entropy nitride films were fabricated by adjusting nitrogen flow via magnetron sputtering.The microstructure,mechanical,electrochemical and tribocorrosion performances of the films were studied.The results show that the films transform from amorphous to nanocrystalline structure as nitrogen flow increased.The nanocrystalline films show super hardness(>40 GPa)and adhesion strength(>50 N).The amorphous film has a pretty anti-corrosion in static corrosion,while not in tribocorrosion condition.The film deposited at nitrogen flow of 38 sccm exhibits the optimal tribocorrosion performance in artificial seawater,with the highest open circuit potential(∼−0.1 V vs.Ag/AgCl),the lowest friction coefficient(∼0.162)and wear rate(∼7.48×10^(−7)mm^(3)N^(−1)m^(−1)).

Tribocorrosion behavior of antibacterial Ti-Cu sintered alloys in simulated biological environments

Ti-Cu alloys have strong antibacterial proper-ties,high strength and excellent corrosion resistance,which might be used in orthopedic and dental implants.In this paper,the tribocorrosion behaviors of Ti-Cu alloy with different Cu contents were investigated in four simulated biological environments compared with cp-Ti.The results showed that Ti-Cu sintered alloy exhibited higher corro-sion resistance,lower coefficient friction and wear loss than cp-Ti in all tested solutions due to the formation of fine and homogeneously distributed Ti_(2)Cu phase,espe-cially in solution with lower F ion and pH.High Cu content and extrusion process improved the corrosion resistance and the wear resistance because of high Ti_(2)Cu phase fraction and fine grain size.However,aggressive solution,such as the solution with lower F ion and pH,accelerated wear in comparison with other solutions for cp-Ti and Ti-Cu sintered alloys.Scanning electron microscope(SEM)surface morphology demonstrated that the wear mecha-nism of cp-Ti during tribocorrosion process was mainly abrasive wear and adhesive wear while that of Ti-Cu alloy was abrasive wear.In summary,Ti-Cu sintered alloys showed much better tribocorrosion property than cp-Ti,which shows great potential application in condition for wear and corrosion resistance.

Structure and tribocorrosion behavior of CrMoSiCN nanocomposite coating with low C content in artificial seawater

CrMoSiCN nanocomposite coatings with a low C content were prepared on Ti−6Al−4V using an unbalanced magnetron sputtering system,and their corresponding microstructures,mechanical properties,and tribocorrosion performance were evaluated in detail.The results revealed that the CrMoSiCN coating had a compact nanocomposite microstructure consisting of CrN and Mo2N nanocrystallites,(Cr,Mo)N solid solution,and Si−C−N amorphous phases.Moreover,the coating exhibited superior mechanical properties with a hardness of 28.6 GPa and an elastic modulus of 273 GPa,owing to the solid solution strengthening effect.The tribocorrosion test results showed that the dominant failure of the Ti−6Al−4V alloy was caused by the corrosion contribution to wear behaviors(synergistic effect).The CrMoSiCN nanocomposite coating could effectively alleviate the material loss caused by the synergistic effect of corrosion and wear behaviors,leading to pure wear behaviors during the entire tribocorrosion process.The corresponding tribocorrosion mechanisms under the open circuit potential and dynamic polarization conditions were discussed in terms of their tribocorrosion behaviors.

Accelerated deterioration mechanism of 316L stainless steel in NaCl solution under the intermittent tribocorrosion process

In this research,the tribocorrosion behavior of 316L stainless steel in simulated seawater was investigated under continuous and intermittent sliding at open circuit potential.The tribocorrosion mechanism was discussed in terms of wear morphologies,mechanical property as well as chemical composition.Meanwhile,microstructure evolution inside the wear track and open circuit potential recorded after sliding were analyzed to quantify the repassivation kinetics and evaluate the impact of the regenerated passive film on wear.The results showed that the wear rate increased under intermittent sliding when the pause time is long enough to repassivate after sliding.Repeated sliding promoted the refinement of the grain inside the sliding area,which was beneficial to the generation of the thicker and more compact passive film inside the wear track.The ruptured passive film often acted as abrasives during subsequent sliding.Therefore,the accelerated material loss under intermittent sliding was attributed to the periodic mechanical removal of the thickened passive film and the enhanced abrasive wear inside the wear track.

Long-term tribocorrosion resistance and failure tolerance of multilayer carbon-based coatings

Current tribocorrosion research of metallic materials and their surface protective coatings mainly focuses on their short-term properties,with test time of 0.5‒2.0 h and a sliding distance 50‒500 m,which may significantly deviate from the practical long-term service condition and thus cause a catastrophe of marine equipments.In this study,three carbon-based multilayer coatings(Ti/DLC,TiC_(x)/DLC,and Ti‒TiC_(x)/DLC)were deposited on S32750 substrates,and both short-term and long-term tribocorrosion behaviors were investigated.The experimental results indicate that the coatings substantially improve the tribocorrosion resistance of the S32750 stainless steel.During the short-term tribocorrosion test,TiC_(x)/DLC exhibited the best tribocorrosion resistance owing to its high hardness.During the long-term tribocorrosion test,however,Ti‒TiC_(x)/DLC coating indicated the best anti-tribocorrosion performance owing to its excellent fracture toughness together with high hardness.Moreover,under 5 N,Ti‒TiC_(x)/DLC can withstand a long-term test of more than 24 h.Additionally,under a higher load of 20 N,the Ti‒TiC_(x)/DLC with a corresponding sliding distance of approximately 1,728 m maintained a low friction coefficient of approximately 0.06.However,the coating was completely worn out;this is attributable to the formation of tribocorrosion products consisting of graphitized carbon and nanocrystalline Fe_(x)O_(y).

Tribocorrosion Behavior and Degradation Mechanism of 316L Stainless Steel in Typical Corrosive Media

The tribocorrosion behavior and degradation mechanism of 316 L stainless steel,in four typically industrial corrosion media,under different potentials,were studied.The results indicated that they strongly depended on corrosion medium and electrode potential.When the potential increased from cathodic protection region to anodic region,corrosion was accelerated.It dramatically promoted mechanical wear which even dominated the total material loss.As a result,the total material loss increased sharply,though the material degradation directly caused by corrosion was slight.This phenomenon was more noticeable when the media were more aggressive.Especially in NaCl solution,the occurrence of pitting corrosion at anodic potential dramatically accelerated the degradation of the stainless steel.There was a special case in NaOH solution under cathodic protection potential.The corrosive reaction could still occur and couple with wear,which led to the abnormally great material loss compared with that in other corrosion media.

An integrated hard- and soft-ware triboelectrochemical test rig for tribocorrosion experiments

Tribocorrosion is a degradation mechanism resulting from the interaction of mechanical(wear)and chemical(corrosion)phenomena.This interaction leads to surface damage that does not correspond to the simple sum of wear and corrosion taken separately.Testing tribocorrosion of material pairings thus requires the capability not only to control the mechanical and chemical test parameters but also to identify the relative contribution of corrosion and wear in the overall material degradation.This paper describes a novel laboratory tribocorrosion test set-up combining in one experiment the control of mechanical input(load,velocity,and frequency)and output(friction and wear)parameters as well as the control of corrosion phenomena through a series of dedicated electrochemical methods(open circuit,potentiostatic and potentiodynamic measurements).The possibilities offered by this set-up are illustrated by selected case studies.

Tribocorrosion Behavior and Degradation Mechanism of 316L Stainless Steel in Alkaline Solution:Effect of Tribo-Film

Tribocorrosion behavior and degradation mechanism of 316L stainless steel(SS)in alkaline solution were studied.The SS was worn in 0.1 mol/L NaOH solution with different potentials to investigate the synergism between wear and corrosion.The SS showed larger material loss at a cathodic potential of-0.8 V and lower material loss at anodic potential when compared with that under pure wear condition.This was inverse when compared with that in other corrosive media,such as H_(2)SO_(4)and NaCl solutions.The formation of Tribo-films with different properties at different potentials played decisive role in the degradation process.Tribo-films were formed at cathodic potential(-0.8 V)and anodic potentials(0 and 0.4 V).The tribo-film formed at-0.8 V had the highest O content and was very brittle.It resulted in the easily peeling off of the film and then the acceleration of material degradation.By contrast,the Tribo-films formed at anodic potentials were more complete and the O content was much lower.Such kind of ductile Tribo-films could protect the SS from wear.The locally high concentration of OH-produced in the reduction reaction of oxygen at-0.8 V could react with the tribo-film which consist of nano-particles(NPs)with high chemical activity and finally led to deep oxidation and embrittlement of the film.The passivation of the NPs at the anodic potentials could inhibit the oxidation of tribo-film to maintain its ductility.

Tribocorrosion properties of AISI 1045 and AISI 2205 steels in seawater: Synergistic interactions of wear and corrosion

Tribocorrosion denotes an irreversible material degradation for several metallic components used in corrosive environments,and it arises from the interplay between chemical,mechanical,and electrochemical processes.In this study,some investigation has been performed to compare the tribocorrosion behavior of AISI 1045 steel and AISI 2205 duplex stainless steel sliding against an alumina pin in seawater.The lowering in the open circuit potential(OCP)of AISI 2205 during the tribocorrosion demonstrates that its protective passive film was damaged by wear and resulted in a wear‐accelerated corrosion in the wear track.However,sliding was found to accelerate the corrosion of the unworn areas for AISI 1045,leading to an anodic shift of the OCP.Moreover,the total material loss increased with an increase in the applied potential for both materials.It was revealed that AISI 1045 was more sensitive to corrosion under sliding than AISI 2205.Therefore,pure corrosion loss and corrosion‐induced wear constituted the primary reasons for the degradation of AISI 1045 at applied anodic potentials.

Improving corrosive wear resistance of Mg-Zn-Y-Zr alloys through heat treatment

The wear behavior of an as-received Mg-Zn-Y-Zr alloy before and after a facile heat treatment was investigated under sliding in air and 0.5 wt.%NaCl solution.Results revealed that the wear resistance of the alloy was remarkably enhanced after the heat treatment,irrespective of testing condition.The wear mechanism was predominantly abrasive wear accompanied by oxidation under the dry sliding condition,while corrosive wear was dominant under sliding in the NaCl solution.The superior corrosive wear resistance was attributed to the homogenous distribution of fine I-phase precipitates in the alloy by the heat treatment,leading to a reduction in wear,corrosion as well as wear-corrosion synergy.The wear-accelerated corrosion rate was remarkably alleviated after the heat treatment.

Effect of friction on corrosion behaviors of AISI 304 and Cr26Mo1 stainless steels in different solutions

The corrosion and tribocorrosion behaviors of AISI 304 austenitic stainless steel and Cr26Mo1 ultrapure high chromium ferrite stainless steel in 3.5 wt.%NaCl and 0.5 mol/L H2SO4 solutions were investigated.Microelectrode electrochemical measurement technology was applied to identify electrochemistry behaviors during tribocorrosion tests in situ.The surface morphologies and compositions of the wear tracks were analyzed by scanning electron microscopy and Raman spectrum.The results showed that compositions of stainless steels,corrosive mediums and applied loads have great influence on tribocorrosion behaviors of stainless steels.Firstly,the corrosion resistance in static state of stainless steels primarily dominates its tribocorrosion behavior;meanwhile,better mechanical properties are in favor of tribocorrosion resistance.Secondly,the corrosion rate is promoted significantly in 3.5%NaCl solution by friction,while the tendency is inconspicuous in 0.5 mol/L H2SO4 solution.Last but not least,passive films on stainless steels can be wiped off by small friction force.With the increase in applied load,the effect of friction converts to forming friction oxide film from removing passivation film,so that a critical load exists below which the friction force can promote the corrosion process extremely.

Ionic liquids as boundary additives in water-based and PAO lubricants

Ionic liquids have been widely discussed as potential lubricants,however,their properties make them also very good potential candidates as lubricant additives(e.g.,friction modifiers and anti-wear).In this work,the tribological study of two ionic liquids(tributylmethylphosphonium dimethylphosphate(PP),and 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate(BMP))as lubricant additives has been performed on stainless steel(AISI 316L)exposed to polar(water-glycol)and non-polar(polyalphaolefin)based lubricants under boundary lubricating conditions.The performance of these ionic liquids as lubricant additives has been compared to a classical organic friction modifier(dodecanoic acid(C12)).The water–glycol lubricant formulated with the two ionic liquids showed friction values higher than the same base lubricant formulated with dodecanoic acid,however,opposite results were observed for polyalphaolefin(PAO).A detailed surface chemical analysis using X-ray photoelectron spectroscopy(XPS)revealed differences in the passive/tribofilm thickness and chemical composition of the stainless steel surface tested in all lubricants.In the case of the polar lubricant additivated with ionic liquids,the tribochemical reaction accompanied by a tribocorrosion process led to the formation of an unstable passive/tribofilm resulting in high friction and wear.However,in the absence of tribocorrosion process(polyalphaolefin base lubricant),the tribochemical reaction led to the formation of a stable passive/tribofilm resulting in low friction and wear.A detailed surface and subsurface investigation of the microstructure using scanning electron microscopy equipped with a focused ion beam(SEM-FIB)showed that high wear rates resulted in thicker recrystallization region under the wear track surface.Among all lubricant additives tested in this work,BMP in non-polar lubricant media showed the best tribological performance.

Recent advances in tribological and wear properties of biomedical metallic materials

Biomedical metallic materials are commonly used in the repair and replacement of human tissues.After the materials are implanted in the human body,the implants can rub against human tissue or other implants,resulting in wear and tear of the implants.The wear and tear of implants in the human body can lead to osteolysis and inflammation,which can affect the longevity of the implant and human health.For the sake of human health and the longevity of implants,it is essential to study the frictional and wear properties of biomedical metallic materials.The present review summarizes the current research on the frictional and wear properties of biomedical metallic materials in recent years,as well as the methods and techniques to improve the frictional and wear properties of the materials.The significance of the present review lies in that it could provide momentus information for further investigation of the tribological properties of biomedical metallic materials.

Improvements in tribological and anticorrosion performance of porous Ti–6Al–4V via PEO coating

Medical implants manufactured using biomaterial Ti–6Al–4V exhibit some disadvantages.Its higher elastic modulus than that of natural bone can cause stress shielding problems.This can be avoided using Ti–6Al–4V with pores in the implant structure.However,poor corrosion and tribocorrosion behaviors are yielded because of the large area exposed to the medium.To mitigate both issues,coating technologies can be applied.The plasma electrolytic oxidation(PEO)process is a cost‐effective process that has been used successfully in nonporous Ti alloys.In this study,two PEO coatings with different amounts of Ca/P are used.However,reports regarding their application in porous materials are scarce.The effects of PEO treatments on corrosion and tribocorrosion in Ti–6Al–4V powder metallurgy are analyzed herein.The porous materials provide an efficient surface for PEO coatings,as demonstrated via scanning electron microscopy(SEM)and atomic force microscopy(AFM),and the porosity of the substrates improved the adherence of the coatings.The corrosion resistance measured via electrochemical impedance spectroscopy confirmed the beneficial effect of the coatings,particularly for long exposure time.The lower roughness,small pore size,and more compact film observed in the PEO–Ca/P sample resulted in favorable tribological and corrosion properties.