Superior Wear Resistance Research Articles

A comparative study on characteristics of composite (Cr3C2-NiCr) clad developed through diode laser and microwave energy

A typical ferrite/martensitic heat-resistant steel (T91) is widely used in reheaters, superheaters and power stations. Cr3C2-NiCr-based composite coatings are known for wear-resistant coatings at elevated temperature applications. The current work compares the microstructural studies of 75 wt% Cr3C2- 25 wt% NiCr-based composite clads developed through laser and microwave energy on a T91 steel substrate. The developed clads of both processes were characterized through a field emission scanning electron microscope (FE-SEM) attached with energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and assessment of Vickers microhardness. The Cr3C2-NiCr based clads of both processes revealed better metallurgical bonding with the chosen substrate. The microstructure of the developed laser clad shows a distinctive dense solidified structure, with a rich Ni phase occupying interdendritic spaces. In the case of microwave clad, the hard chromium carbide particles consistently dispersed within the soft nickel matrix. EDS study evidenced that the cell boundaries are lined with chromium where Fe and Ni were found inside the cells. The X-ray phase analysis of both the processes evidenced the common presence of phases like chromium carbides (Cr7C3, Cr3C2, Cr23C6), Iron Nickel (FeNi3) and chromium-nickel (Cr3Ni2, CrNi), despite these phases iron carbides (Fe7C3) are observed in the developed microwave clads. The homogeneous distributions of such carbides in the developed clad structure of both processes indicated higher hardness. The typical microhardness of the laser-clad (1142 ± 65HV) was about 22% higher than the microwave clad (940 ± 42 HV). Using a ball-on-plate test, the study analyzed microwave and laser-clad samples' wear behavior. Laser-cladding samples showed superior wear resistance due to hard carbide elements. At the same time, microwave-clad samples experienced more surface damage and material loss due to micro-cutting, loosening, and fatigue-induced fracture.

Corrosion and abrasion behavior of high-temperature carburized 20MnCr5 gear steel with Nb and B microalloying

This paper investigates the effect of Nb and B microalloying on the wear and corrosion resistance of 20MnCr5 steel after high-temperature carburization at 950 °C. The abrasion and corrosion performance of the steel was compared using electrochemical experiments and dry sliding wear tests. The results show that Nb microalloying reduces the size of residual austenite, thereby improving the wear resistance of 20MnCr5 steel. Furthermore, the combination of Nb and B microalloying reduces the amount of residual austenite, leading to further improvements in wear resistance. Both microalloying methods reduce the wear scar depth and debris accumulation. The corrosion potentials of 20MnCr5, 20MnCr5Nb, and 20MnCr5NbB are 0.645 V, 0.627 V, and 0.675 V, respectively. The addition of Nb to 20MnCr5 steel results in higher corrosion resistance after carburization due to the refinement of needle-like martensite. However, 20MnCr5NbB steel exhibits low corrosion resistance due to the coarsening of needle-like martensite caused by B microalloying. In summary, this study provides new insights into the effects of microalloying elements on the properties of steel. The findings contribute to a deeper understanding of how to design and manufacture gears and other components with superior wear and corrosion resistance.

Influence of compositional and microstructural gradient on the wear performance of nanocrystalline Ni–W coatings

Although the nanocrystalline Ni–W coatings offer superior wear resistance, under sufficiently higher loads and strain rates they often suffer from the strain localization which leads to a severe wear damage. Further, the presence of tensile residual stresses exaggerates the situation. Herein, we report a facile approach of microstructural gradation to circumvent this problem. Present study investigates the sliding wear performance of gradient nanocrystalline Ni–W coatings prepared by pulse electrodeposition. By tailoring the W-content along the deposition direction, a concomitant modulation in the microstructure, hardness and elastic modulus was obtained as revealed by the depth-wise glancing incidence XRD and nanoindentation, respectively. The gradient Ni–W coatings have demonstrated a low coefficient of friction (CoF) and superior wear resistance over their homogeneous counterparts. The micro-Raman spectroscopy has indicated the formation of tribo-oxide layer composed majorly of CoWO4, WO3 and NiO on the surface of the wear tracks. Based on the crystal-chemical model, the lower CoF of gradient Ni–W is attributed to the presence of a stable and adherent tribo-oxide. Furthermore, the enhanced wear resistance of the gradient Ni–W coating is ascribed to the lower tensile residual stresses, strain delocalization and its higher thermal diffusivity.

Experimental investigation of the high temperature sliding wear behaviour of RSM optimized YSZ-Inconel 625 TIG weld cladding

Yittria stabilized zirconia (5–25weight %) reinforced Inconel 625 composite claddings were developed using TIG welding. The optimal TIG welding process parameters were predicted through response surface methodology (RSM) based Box-Behnken design (BBD). Developed cladding and worn-out specimens were examined using optical microscopy, SEM, EDS, and XRD analysis techniques. The sliding wear behaviour of the claddings at 650 °C was assessed by a high-temperature pin-on-disk tribometer. The YSZ-Inconel 625 composite claddings exhibited the growth of stable phases and solid stable oxides such as γ-Ni, Cr2O3, and ZrO2. The claddings exhibited mainly an adhesive type of wear at high temperature. The compact solid oxide layers in the cladding developed at an optimized setting resulted in superior wear resistance compared to other claddings.

Superior wear resistance in cast aluminum alloy via femtosecond laser induced periodic surface structures and surface hardening layer

Cast Al alloys have been increasingly used in aviation, shipping, aerospace, and automotive industries as important raw materials of engine parts. However, its poor wear resistance hampered their application in some tribological environments. To overcome the current issue, in present work, we proposed a femtosecond laser (fs-laser) surface processing strategy to fabricate pillar-shaped laser induced periodic surface structures (LIPSS), as well as a work-hardening layer (hardness increment reached 51.2% compared with that of substrate) with an affected depth of ∼ 75 μm, on the surface of cast Al alloy in one step. In this case, the wear performance of processed samples showed an obvious improvement with a 49.4% reduction of the cross sectional area of wear track. Our work broke the existing understanding about the strengthening mechanism of fs-laser surface modification technology, in which surface texture or shock wave induced by fs-laser were viewed as two isolated strengthening effects. For the first time, we achieved the combination of these two strengthening effects, and proved the effectiveness of this strategy. The present results provided theoretical bases for the further development of novel fs-laser surface technologies with better performance.

Design and milling performance investigation of a new PCBN multi-edge ball milling and grinding composite tool

The structure and material of micro tools have a significant impact on their machining performance. To improving the machining performance and wear resistance of micro milling tools, a new PCBN multi-edge ball milling and grinding composite tool (ME-BMGT) with multi-edge and spherical flank is proposed. The micro milling experiment results show that, compared with the cemented carbide double-edged ball-end milling tool (OMBMT), the micro groove morphology machined by the ME-BMGT has grinding texture characteristics, the micro groove surface quality is better, and the burr height is smaller. The wear morphology shows that the wear form of ME-BMGT is adhesive wear, while the wear form of OMBMT is cutting edge fracture and adhesive wear. The ME-BMGT provides superior wear resistance.

Tribological properties and wear resistance mechanism of WC-ZrO2-Al2O3 ceramics

Tungsten carbides are typically used in milling and cutting processes, but the tendency for the metallic phase to be easily softened in high-temperature environments makes them susceptible to severe wear during high-speed cutting and repeated friction processes. In this paper, ceramic phase (ZrO2-20 wt% Al2O3 composite powder) was used to replace the metallic phase and to improve the sustainability of the tribological properties of such material. Furthermore, the wear mechanism of WC-ZrO2-Al2O3 ceramics was compared with monolithic WC ceramics. The ZrO2/Al2O3 grains performed a critical function by forming the relief structure during the friction process. This structure was generated in-situ on the worn track and would not be consumed as the friction process progressed. The excellent wear resistance was attributed to the improved comprehensive mechanical properties of the material and the formation of the relief structure. The best tribological properties of WC-ZrO2-Al2O3 ceramics against GCr15 steel balls represented a coefficient of friction of 0.51 and a specific wear rate of 3.3 × 10−7 mm3·N−1·m−1. This success displays a universal approach of the relief structure formed during the friction process for developing other structural ceramics with superior wear resistance.

TiC–Fe gradient coating with high hardness and interfacial adhesion strength on cast iron prepared by in-situ solid-phase diffusion method

The improvement of comprehensive properties including hardness, toughness, wear, and adhesion strength of the coating-substrate system, especially avoiding the trade-off between the hardness and adhesion strength, is strongly required for various applications. Herein, an effective strategy is proposed, by in-situ solid-phase diffusion method, to fabricate a novel TiC–Fe gradient coating with high hardness and interfacial adhesion strength on cast iron. The eveloped coating was composed of equiaxed TiC particles and α-Fe phase. The microstructure was graded in TiC size and volume fraction. The formation of the graded microstructure was attributed to the nucleation-growth process controlled by diffusion of the carbon concentration gradient. The TiC volume fraction in the coating was as high as 95%. The phase interface (TiC/TiC interface and TiC/α-Fe interface) and the coating/substrate interface exhibited excellent interfacial bonding at the atomic scale. The novel gradient coating could simultaneously achieve high hardness (23.9 ± 1.3 GPa), high elastic modulus (265.7 ± 9.4 GPa), and excellent adhesion strength (>225 ± 10 MPa). Apparently, in-situ solid-phase diffusion method may provide a new route to fabricate TiC–Fe gradient coatings with high-volume fraction on steel/iron, capable of capable of exhibiting elevated hardness, high elastic modulus, excellent interfacial adhesion strength, and superior wear resistance.

Role of carbide content in governing the mechanical and tribological properties of DLC/Cr3C2–NiCr duplex coatings

Effects of carbide content on the mechanical and tribological properties of DLC/Cr3C2–NiCr duplex coatings were systematically investigated. Results revealed that cermet coating with high carbide content provided strong support for the top DLC film by bearing most of the contact stress, thus improving its hardness, load-bearing capacity, and adhesion strength. The increased carbide content increased the contact and shear stresses on duplex coating during the friction process, intensifying the graphitization of the top DLC film but inhibiting the formation of a graphitized transfer film on the counterpart, thus slightly increasing its friction coefficient. However, the predominant wear mechanism changed from high-efficiency abrasive wear to low-efficiency adhesive wear for low to high carbide content, superior wear resistance was thereby achieved.

Effects of nano-Al2O3 addition on microstructure, mechanical properties, and wear resistance of Ti(C, N)-based cermets

To enhance high-temperature wear resistance and cutting performances of cermet tools, nano-Al2O3 particles were added into four kinds of Ti(C,N)-based cermets. The microstructure, mechanical properties, wear resistance, and cutting performances were studied. The nano-Al2O3 was supposed to distribute in the binder phase, leading to the change of lattice constants and dispersion strengthening. Due to the distribution of nanoparticles at the grain boundaries, the movement of the grain boundaries was hindered, and the mean grain size decreased from 1.03 μm to 0.89 μm. The hardness and fracture toughness showed the change tendency of rising the peak and then falling with nano-Al2O3 addition. The cermet with 2 wt% nano-Al2O3 displayed the topmost hardness of 1654.4 HV30 and fracture toughness of 9.1 MPa·m1/2, due to the dispersion strengthening and pinning effect of nano particles. During the sliding wear tests at 700 °C, the wear rates of cermet containing 2 wt% nano-Al2O3 decreased by 63% compared to cermet without nano-Al2O3. The superior high-temperature wear resistance was ascribed to the thermal softening resistance of nano-Al2O3, the strengthening and toughening effect of nano-Al2O3 on matrix and the dense tribo-chemical layers. The abrasive wear of cermet with no nano-Al2O3 addition was more significant, while the wear behavior changed to the removal of tribo-chemical layers when nano-Al2O3 was 2 wt%. The tool life of cermet with 2 wt% nano-Al2O3 was increased by 50% in comparison with cermet without nano-Al2O3 during machining 45 steel.

Organohydrogels with High‐Speed Lubrication by Confining Polymer Chain Mobility by an Interpenetrated Heteronetwork

AbstractHydrogels with pure hydrophilic network have received much attention due to their excellent low frictional behavior. However, the lubrication performance of hydrogels is not satisfied under high‐speed condition due to the energy dissipation caused by adsorbed polymer chains as well as the failure of lubricating mechanisms accompanied by the transition of lubrication regime. In this work, interpenetrating double‐network organohydrogels were constructed by combining hydrophilic and oleophilic polymer networks to modify the physiochemical properties of surface polymer chains, especially the chain mobility. The oleophilic polymer network spatially restricting the mobility of the swollen hydrophilic network in water, resulted in a low coefficient of friction (ca. 0.01) compared with conventional hydrogels at high speed (0.1 m s−1). Meanwhile, the organohydrogels had superior wear resistance, with almost no wear observed on the sliding track after 5 k cycles of rubbing at high speed. The design concept of organohydrogels can be extended to a variety of low‐wear, highly‐lubricating materials.

Organohydrogels with High-Speed Lubrication by Confining Polymer Chain Mobility by an Interpenetrated Heteronetwork.

Hydrogels with pure hydrophilic network have received much attention due to their excellent low frictional behavior. However, the lubrication performance of hydrogels is not satisfied under high-speed condition due to the energy dissipation caused by adsorbed polymer chains as well as the failure of lubricating mechanisms accompanied by the transition of lubrication regime. In this work, interpenetrating double-network organohydrogels were constructed by combining hydrophilic and oleophilic polymer networks to modify the physiochemical properties of surface polymer chains, especially the chain mobility. The oleophilic polymer network spatially restricting the mobility of the swollen hydrophilic network in water, resulted in a low coefficient of friction (ca. 0.01) compared with conventional hydrogels at high speed (0.1 m s-1 ). Meanwhile, the organohydrogels had superior wear resistance, with almost no wear observed on the sliding track after 5 k cycles of rubbing at high speed. The design concept of organohydrogels can be extended to a variety of low-wear, highly-lubricating materials.

In Situ Formation of Al3Ti and Its Effects on the Microstructure, Hardness and Tribological Properties of Al Matrix Composites with Various Ti Contents

At present, Al matrix composites (AMCs) have drawn much attention owing to their light weight, high specific strength, high thermal conductivity, and superior excellent wear resistance, which endows them with great potential in the aerospace, automobile and military industries. In this study, AMCs with different Ti contents (0, 5 and 10 vol.%) were prepared by powder metallurgy. During the sintering, Al3Ti particles were in situ formed in the Al matrix. It was found that the Ti completely reacted with the Al matrix and formed fine in situ Al3Ti particles in Al-10Ti, while some large Ti-Al3Ti core-shell formed in Al-5Ti due to the incomplete reaction between the Ti and the Al matrix. Furthermore, the hardness of the composites was significantly improved by the in situ formed Al3Ti particles, reaching 143.3 HV in Al-5Ti and the highest value at 331.2 HV in Al-10Ti, respectively. The wear resistance of the composites is remarkably enhanced by Al3Ti particles compared to the unreinforced Al. Al-5Ti has the highest wear resistance among the samples. The wear resistance of the Al-10Ti composite becomes slightly deteriorated compared to Al-5Ti due to the brittle nature of Al3Ti, which leads to a three-body abrasive wear.

Wear and Corrosion Performance of Ti-6Al-4V Alloy Arc-Coated TiN/CrN Nano-Multilayer Film

The objective of this study was to investigate the effect of varying bias parameters (−50 V, −100 V, and −150 V) on the properties of TiN/CrN multilayer films deposited on Ti-6Al-4V alloy using the cathodic arc deposition (CAD) technique. The deposited films were characterized for their composition, structure, morphology, thickness, adhesion, and hardness. Wear and polarization tests were also conducted to determine the optimal bias condition for wear and corrosion resistance. The results showed that the TiN/CrN films possessed a nano-multilayered structure comprising TiN and CrN phases. The hard coating significantly increased the surface hardness of Ti-6Al-4V alloy up to three–five times. The coated specimens demonstrated superior wear resistance compared to the uncoated, with the −150 V specimen exhibiting the least wear rate. Furthermore, the −150 V specimen had the highest polarization impedance value, indicating the best corrosion resistance compared to the other bias conditions. In short, the use of CAD-coated TiN/CrN multilayer film enhanced the surface properties of Ti-6Al-4V alloy, with the best wear and corrosion resistance achieved at −150 V bias. These novel findings have significant implications for improving the performance and durability of Ti-6Al-4V alloy components in various industrial applications.

Tribological characteristics of aluminium alloy composites manufactured by liquid state casting process – A review

The global requirement for good quality and superior performing composites has led to research in hybrid metal matrix composite materials. In metal matrix composites, Al alloy composite has been chosen widely because of its high strength-to-weight ratio and superior wear resistance. Reinforcements like particulate Al2O3, SiC, fly-ash and graphite, etc. can easily be included in the melt using a liquid state casting process. In order to fulfil the essential need for elaborating their application, conventional stir casting method is employed which is economical for fabricating composite material when compared to other solid-state and liquid-state processes. This paper mainly focuses on the tribological properties and problems incorporated at the time of stir casting process of aluminium alloy composites containing one or more reinforcements. It provides inputs on the reinforcement incorporated, the matrix composition and the interface overlap and distribution each of which is critical in determining the performance of the composite. Processing AMMCs is straight forward using stir casting process, which is the most inexpensive and robust process that can be used on a wide scale, while other methods are confined to laboratories alone.

Evaluation of microstructural, tribological and tensile characteristics of AA7075 surface composites fabricated through friction stir process

Superior wear resistance and a high level of tensile strength in piston ring materials are achieved using AA7075 surface composites (SCs) that are fabricated by reinforcing the steel slag (SS) particulates through proper selection of friction stir process (FSP) parameters using the multipass technique. The optical structure elucidates that fine and equi-axed grains are ascertained in the stir zone of the processed region, and by increasing the number of passes from one to three, a homogenous dispersion of particulates and a reduced grain size (9 µm) is obtained. In particular, a clear and defect-free interface is prominent on the resulting composite surface. Field emission – scanning electron microscopy (FESEM) identifies the dispersion of reinforcements, while X-ray diffraction (XRD) technique and energy dispersive spectroscopy (EDS) mapping confirm the existence of reinforcing elements. The Orowan strengthening effect and reduced oxygen content around the SiO2 and CaO elements in the three-pass FSP SC specimen tend to increase its load-bearing capacity and result in superior hardness (353.3 VHN) and tensile strength (792.6 MPa). However, the same specimen exhibits a reduced percentage (%) elongation due to multiplied fragmentation of reinforcements, which eventually restricts the plastic movement of the AA7075 matrix. The SEM fracture morphology indicates that failure occurred through a combination of ductile and brittle modes. Furthermore, the SC specimen with two passes prominently decreases the wear rate (333 × 104 mm3/m), which can be attributed to the commendable trilayer formation, and the worn morphology indicates the abrasive wear was the dominant wear mechanism. This fabricated specimen with high-strength characteristics can be beneficial for design engineers. During piston ring design, an increased level of the factor of safety can be achieved.

Annealing Effect on Microstructure of Novel Ti Doped DLC Multilayer Films

Diamond-like films (DLC) are an exceptional engineering material with excellent performance such as high hardness, low friction coefficient, superior wear resistance and chemical inertness. However, two major problems of high internal stress and poor thermal stability have seriously limited its industrial applications. In particular, the microstructures and properties of pure DLC films are highly sensitive to high temperature. Therefore, the purpose of this study is to investigate the effect of annealing temperature on the microstructures of the as-prepared films. Ti-doped DLC multilayer films were synthesized by closed field unbalanced magnetron sputtering. The as-deposited films were annealed in the range of 200 to 800 °C. The surface morphology, phase structure and bonding structure of the films were characterized by SEM, AFM, GIXRD and Raman spectroscopy. The resulting films remained a smooth surface after annealing and maintained the nature of amorphous carbon up to 600 °C. The formed phases of graphite carbon and TiC nanocrystallines occur above 600 °C. In addition, the D- and G-bands showed a significant blue shift and the FWHMG shows a declining trend up to 600 °C. This result revealed that the films had high graphitization temperature and good thermal stability due to the formation of TiC nanocrystallines and its novel structure design containing elemental doping, multilayer structuring and functionally graded layering.

Structural and Tribological Characterization of Carbon and Glass Fabrics Reinforced Epoxy for Bushing Applications Safety.

This article investigates the effect of geometrical alternatives for fiber directions on the structural and tribological properties of glass and carbon fibers when molded with epoxy as polymeric composite fabrics for the safety and quality of bushing applications. To confirm the best composite fabric direction, scanning electron microscope and tribological analyses were carried out for the glass and carbon fabrics at horizontal and vertical geometrical alternative orientations. The tribological test was applied using a pin-on-disk tribometer at constant bark velocity of 0.520 m/s against different loads, beginning with 5, 10, 15, and 20 N for the investigated composite samples. The structural measurements demonstrated that the carbon fiber had a high ability to merge with the resin epoxy when compared with the glass fiber. The tribological analysis elucidated that the lower wear volume loss and friction coefficient were obtained when molding the resin epoxy horizontally to the fiber-stacking direction compared with the other vertical direction. Accordingly, the study deduced that the carbon fiber composite material achieves superior wear resistance when molded by resin epoxy horizontally to the direction of tribological wear, which is suitable for several advanced bushing applications.

Effect of Boron Carbide Particles Addition on the Mechanical and Wear Behavior of Aluminium Alloy Composites

In this research, synthesis and assessment of the mechanical and wear possessions of Al7049-nano B4C composites are determined by experiments. Using the liquid metallurgy route, a stir casting technique was used to create composites with increasing concentrations of nano B4C from 3 to 9 weight %. Each composite’s reinforcement particles were heated to 400 degrees Celsius before being added to the molten Al7049 alloy in two separate steps, i.e., two-stage stir casting to optimise wettability and distribution. Scanning electron microscopy (SEM) was utilised to examine the microstructure, and energy dispersive spectroscopy (EDS) was utilised to determine the elemental make-up. Mechanical characteristics of composites were determined by subjecting them to tensile, compression, and hardness tests. Wear tests were conducted as per ASTM G99 standards with varying loads and speeds. Nanosized B4C particles were found to be dispersed throughout the sample space in a microstructural analysis. Hardness, ultimate strength, yield strength, and compression strength of Al7049 alloy composites were found to increase significantly as the weight percentage of nano B4C was increased. Additionally, compared to the unreinforced form, the ductility of the Al7049 alloy composites was slightly reduced. SEM micrographs of tensile-fractured specimens were used for research into the field of tensile fractography. Nano B4C reinforced composites exhibited superior wear resistance as compared to Al7049 alloy. These prepared composites can be used for wing root fitting of an aircraft.

Investigation of the microstructure, mechanical and wear performance of friction stir-processed AA6061-T6 plate reinforced with B4C particles surface composite

In this work, friction stir processing (FSP) was used to successfully embed boron carbide (B4C) particles into an aluminum matrix (AA6061-T6). Four specimens of aluminum 6061 composite reinforced with 4%, 6%, 8%, and 10% volume fraction of B4C were manufactured. The effects of B4C particles volume fraction on microstructure, mechanical and wear properties are investigated. The microstructural investigations demonstrated that a rise in the volume % of reinforcement greatly decreased the matrix grain size. The manufactured AA6061-T6 loaded with B4C surface composites demonstrated homogeneous B4C particle dispersion, with no significant particle clustering in the stir zone. In addition, it was established that increasing the volume fraction of B4C particles promoted grain refinement, increased hardness, and tensile strength. X-ray diffraction (XRD) was used to identify the reinforcement dispersion. For AA6061-T6 with 10% B4C particles, a maximum hardness value of 163 HV was obtained in the stir zone. Maximum yield strength of 165 MPa and ultimate tensile strength of 220 MPa were attained by AA6061-T6 with 10% B4C particles, which is an improvement of 21% over the specimen FSP without reinforcement. The strengthening of the grain refining was attributed for the increase in hardness and strength. The ductility was reduced by the incorporation of more B4C particles. Comparing the surface composite loaded with B4C to unreinforced friction stir processing and AA6061-T6 as received, it demonstrated superior wear resistance.