Wear Mass Loss Research Articles

Influence of laser power on the microstructure and properties of in-situ NbC/WCoB–TiC coating by laser cladding

In this research, in-situ synthesized NbC in the WCoB–TiC composite coating was fabricated via laser cladding with variable laser power. The microstructure, elemental distribution, microhardness, wear resistance, and fracture toughness were analyzed. The results showed the excellent metallurgical bonding between the coating and the substrate was formed. With the increase of laser power, the grain size of the coating increased, and density decreased. Elemental distribution results showed that niobium reinforced phases were distributed uniformly in the TiC. Following the increase of laser power, the dilution rate increased, while the porosity and crack showed opposite results. The microhardness was decreased following the increase of laser power, and the highest microhardness of coating reached 2034.4 HV0.5 when the laser power was 1500 W. When the laser power was 2500 W, the COF, wear mass loss, and KIC were 0.49, 4.3 mg, and 8.31 MPa⋅m1/2, respectively. The wear form of the composite coating was mainly adhesive wear and abrasive wear. In summary, the microhardness, wear resistance, and fracture toughness can be significantly improved by adjusting laser power.

Investigation of Dry Sliding Wear Behavior of Mg-SiC Alloys Produced by Powder Metallurgy Method

In these days, Mg alloys have great promise for weight-saving applications, because of their superior properties over monolithic metals, in the field of automotive and aerospace industries. In this study, the dry sliding wear behaviour of Mg- SiC alloys with different sintering temperature (375 °C, 400 °C, 425 °C) were investigated. Mg with %10 weight SiC powders were mechanically mixed and alloyed and then fabricated successfully via fast heating under vacuumed argon atmosphere. The friction coefficient, hardness value, and wear resistance of the alloys were higher than those of the pure Mg. The increase in the sintering temperature of the Mg-SiC alloys up to 425 °C caused an increase in the friction coefficient and a decrease in the wear mass loss respectively.

Effect of laser energy density on microstructure, wear resistance, and fracture toughness of laser cladded Mo2FeB2 coating

To expand the applications of Mo2FeB2 ternary borides in industry, laser cladding technology was utilized to prepare Mo2FeB2 coating to improve the properties of the AISI 1045 medium steel substrate. The influence of cladding laser energy density (75–175 J⋅mm−2) on the obtained coating properties was studied, such as geometric characteristics, microstructure, microhardness, wear resistance, and fracture toughness. It can be found from the results that width and dilution rate increased with the increase of laser energy density when the coating had the same scanning speed or laser power, while the wetting angle had an opposite result. The ability of Marangoni convection was increased with the increase of laser energy density, and the hard phase particles became coarse and formed needle-like structures and herringbone structures. An excellent bonding zone was formed between the coating and the substrate. The direction of crystal structures in the bonding zone grew along the direction of heat dissipation. Based on the results of the mechanical properties of the coating, it can be concluded that the coating fabricated with 90 J⋅mm−2 laser energy density had the highest microhardness (1283.7 HV0.5) and excellent wear resistance (0.34 coefficient of friction, 2.9 mg wear mass loss). The wear forms were typical abrasive and adhesive wear, where a smooth worn surface was formed, and only pits or shallow grooves existed. The coating obtained with the highest laser energy density (175 J⋅mm−2) had a high fracture toughness value (16.73 MPa⋅m1/2). Besides, the coatings had typical transgranular fractures with different laser energy densities. Hence, a coating with perfect properties can be fabricated by adjusting laser cladding parameters.

Improvement of structural/tribological properties and milling performances of tungsten carbide cutting tools by bilayer TiAlN/TiSiN and monolayer AlCrSiN ceramic films

In this study, bilayer TiAlN/TiSiN and monolayer AlCrSiN ceramic films were grown on carbide cutting tool material by cathodic arc physical vapor coating (CAPVD) method to improve the structural/tribological properties and milling performances. The ceramic films were applied on cylindrical test samples and carbide end mills. The coated materials' structural, mechanical, and tribological properties were determined via scanning electron microscope (SEM), X-ray diffraction meter (XRD), tribometer, microhardness tester, and optical profilometer. DIN 40CrMnNiMo8-6-4 steel workpieces were machined by using a CNC vertical machining center to determine the actual working performance of the coated and uncoated cutting tools. The wear performance of the cutting tools after machining was determined by measuring the flank wear widths and mass losses. The hardness and adhesion results of the coated sample with bilayer TiAlN/TiSiN were higher than the coated sample with monolayer AlCrSiN. According to the scratch test results, the best adhesion results were obtained for TiAlN/TiSiN coating. The critical load value was determined as about 105 N. As a result, the wear rate value of the TiAlN/TiSiN thin film coated sample was lower. After machining, the mass loss of TiAlN/TiSiN coated tools was lower than AlCrSiN coated tools. In addition, the surface roughness value of the workpiece machined by the cutting tool coated with AlCrSiN was higher than the cutting tool coated with TiAlN/TiSiN.

Influence of Plasma Arc Current on the Friction and Wear Properties of CoCrFeNiMn High Entropy Alloy Coatings Prepared on CGI through Plasma Transfer Arc Cladding

High-entropy alloys receive more attention for high strength, good ductility as well as good wear resistance. In this work, CoCrFeNiMn high-entropy alloy (HEA) coatings were deposited on compacted graphite iron through plasma transfer arc at different currents. The microstructure and wear properties of the CoCrFeNiMn HEA coatings were investigated. The coatings are composed of single phase with FCC structure. The CoCrFeNiMn HEA coating had the highest microhardness of 394 ± 21.6 HV0.2 and the lowest wear mass loss when the plasma current was 65 A. All of the HEA coatings had higher friction coefficients than that of the substrate. There were adhesive, abrasive and oxidation wear forms in the HEA coatings with the wear couple of N80 alloy. The HEA coating presented higher friction coefficient and better wear resistance than compacted graphite iron.

Influence of Annealing Treatment on Microstructure and Properties of Ni-Rich NiTi Alloy Coating Prepared by Laser Cladding.

NiTi alloys are widely known for their shape memory effect and super-elasticity. In this study, the laser cladding method was applied to prepare Ni-rich NiTi alloy coatings on 316L stainless steel substrate. The microstructure, phase composition, element distribution and phase transformation behavior of the coatings were investigated in as-fabricated and annealing-treated states. The results indicated that the recrystallized microstructure obtained and the content of Ni3Ti and Ti2Ni phases increased significantly with a rising annealing temperature. Annealing treatment also induced a decrease in the phase-transition enthalpy and a rise in the transformation temperature, even though no obvious martensite transformation was observed. This was suppressed due to the Fe element diffused from the substrate and was probably retarded by the mounting metallic compounds formed during annealing as well. The mechanical properties have also improved obviously; coatings annealed under 850 °C exhibited the highest microhardness of 839 HV, and the wear resistance of the coatings after annealing was enhanced with an 11% average wear mass loss reduction.

Mechanical Loading and Tribological Studies on Boron Carbide (B4C) and Lead (Pb) Particles Dispersed Epoxy-Based Multilayered Composites

The study aims in the development of functionally graded epoxy-based layered composites dispersed with B4C and lead particles. The development route adopted for the composites is a novel route called layered molding and curing. Various compositions of single and trilayered composites were prepared through the abovementioned route. The samples prepared were subjected to mechanical and tribological studies, and the results were reported in this article. It is found that the mechanical properties of the single-layered composites consisting of 20% lead and 20% B4C show superior characteristics than those of the samples with increased addition of lead. However, the trilayered samples with lead core showcased excellent mechanical properties. On the other hand, the wear rate and mass loss of the trilayered samples with B4C cladding show minimum wear rate than the samples with lead cladding. Furthermore, the coefficient of friction of the samples also showcases the better performance of single-layered samples with 20% lead. The worn surface analysis done through scanning electron microscopy and stereo zoom microscopy reveals the reason for the low specific wear rate of 20% lead sample as the self-hindrance of wear debris evolved during the wear study.

Effects of Biomass Fast Pyrolysis Fuel on the Tribological Behaviour of Heavy-Duty Diesel Engine Lubricating Oil

The fuel type not only influences the engine power and exhaust emissions, but dilutes the lubricating oil. We studied the effects of biomass fast pyrolysis fuel, or biofuel, on the tribological behaviour of a fully formulated engine oil (FFEO) used for heavy-duty diesel engines by reciprocating a sliding tribometer, which simulated the tribological conditions of an engine cylinder liner and piston ring. We analysed the surface morphology, surface roughness, and elemental contents of countersurfaces through scanning electron microscopy/energy dispersant spectroscopy and surface roughness measurements. The wear mechanism was studied by analysing the compositions and kinematic viscosities of the oil samples. The results indicate that the friction coefficient increased along with the emulsified biomass fuel (EBF) content in FFEO. The wear mass loss and EBF content were simultaneously increased. The wear mechanism was mainly attributed to the corrosion function of the biofuel.

Parallel Tubular Channel Angular Pressing (PTCAP) Processing of the Cu-20.7Zn-2Al Tube.

Commercial Al-brass tube was successfully processed by Parallel Tubular Channel Angular Pressing (PTCAP) in 2 passes under an imposed strain of 1.49 per pass. The effect of the number of PTCAP passes on the microstructure and the mechanical properties (hardness, tensile, and wear mass loss) of the Al-brass tubes was fully investigated. The average grain size of the as-received tube decreased to 1.28 μm after up to two passes of PTCAP with a mixture of ultrafine grain (UFG) and coarse grain (CG). The annealed tubes’ tensile strength and Vickers hardness increased by 237.65% and 175.6%, respectively, after two passes. In addition, a ductile fracture occurred with a clear necking. The fracture surface morphology indicated an apparent decrease in dimple size after PTCAP processing, combined with a decrease in ductility. Moreover, the wear mass loss decreased with increasing number of PTCAP passes due to the decrease in the grain size, and the increase of the hardness of the tubes was enhanced after PTCAP processing.

Wear Properties of Iron-Based Alloy Coatings Prepared by Plasma Transfer Arc Cladding

Plasma transfer arc cladding technology has been widely utilized in surface engineering, repairing and remanufacturing. In the present work, multiple cladded thick claddings were prepared on compacted graphite cast iron (CGI) substrates with iron-based powders through plasma transfer arc cladding technology using different plasma arc currents to improve the surface wear resistance. The coatings’ phase and microstructure were analysed through XRD, SEM and EDS. The coatings’ microhardness and wear resistance were characterized. There were pearlite, graphite, austenite and secondary carbides in the iron-based alloy coatings. Due to the heat influence during the multiple cladding process, a spheroidal graphite transition zone appeared between the substrate and the coating. The microhardness of the claddings varied from 363 to 402 HV as the plasma arc current was changed from 45 to 60 A. With the increase of plasma arc current, the cladding’s microhardness increased. The iron-based coating’s minimum friction coefficient and wear mass loss were about 0.48 and 4.2 mg, respectively, when the plasma arc current was 60 A, which are lower values than those of the compacted graphite iron substrate with the friction coefficient and wear mass loss of 0.55 and 8.2 mg. Compared with the substrate, the iron-based alloy claddings achieved the effect of reducing friction and wear resistance simultaneously, which resulted from the self-lubricating effect of graphite and high wear-resistance of carbides in the claddings. The iron-based coatings had a similar abrasive wear mechanism to the CGI, which should be helpful to repair or remanufacture CGI workpieces.

Relative effect of wear parameters on the wear behavior of TiAlN coated tool steel and parametric optimization using MCDM method

ABSTRACT This study focuses on the relative effect of wear parameters and their optimisation for wear responses of TiAlN coating deposited on MDC-K tool steel using cathodic arc deposition technique. Taguchi L27 design of experiment was employed to design the experimental run with three wear parameters, namely, applied load (N), sliding velocity (Sv) and sliding distance (Sd). The dry sliding wear test was performed against the tungsten carbide (WC) counterbody to evaluate the wear behaviour of TiAlN coating. The wear behaviour evaluation was conducted based on the responses such as surface roughness, friction coefficient, wear mass loss, wear depth and worn surface hardness. The worn surface morphology reveals that micro-grooves and micro-ploughing were dominant wear mechanism at lower applied load, whereas coating delamination was evident at higher load values. ANOVA results show that the applied load was the most influential parameter with >63.27% contribution compared to other parameters. Finally, multi-criteria decision-making approaches were employed to optimise the wear parameter. The obtained result suggests the parameter combination of L= 10 N, Sv = 0.2 m/s and Sd = 1500 m to be the best alternative with the optimal value of the wear responses.

Reinforcement of Frictional Vibration Noise Reduction Properties of a Polymer Material by PTFE Particles.

The insufficient lubrication of the contact interface between moving parts can easily induce severe friction vibration and noise under extreme working conditions, which will threaten the service life and reliability of polymer moving components, including water-lubricated stern tube polymer bearings. Thermoplastic polyurethane (TPU) modified by polytetrafluoroethylene (PTFE) particles was developed. The effects of PTFE on the wear and vibration behaviors of modified TPU sliding against the ZCuSn10Zn2 ring-plates were investigated. The coefficients of friction (COFs), wear mass losses, wear morphologies, frictional vibration, and noise were analyzed synthetically. The results showed that a suitable mass content of PTFE reduced the COFs and wear mass losses of the TPU composites by more than 50% and 40%, respectively, while presenting an excellent friction reduction. The lower COFs of modified TPU showed a small fluctuation amplitude and eliminated vibration waveforms at high vibrational frequencies, which was useful for reducing frictional vibration and noise. The knowledge gained in this study is useful for a better understanding of the wear behaviors of polymer composites, as well as for the design a new polymer material with good self-lubricating and frictional vibration and noise reduction properties.

Microstructure and properties of cold sprayed aluminum bronze coating on MBLS10A-200 magnesium-lithium alloy

Aluminum bronze coatings were prepared on MBLS10A-200 magnesium-lithium alloy substrate by cold spraying technology to improve the surface properties of Mg–Li alloys. The microstructure, phase composition, microhardness, tribological properties and corrosion resistance of the coatings were systematically analyzed. The results show that aluminum bronze coatings are mainly composed of α phase. β phase in the original aluminum bronze powder disappeared in the coating due to the eutectoid transition of β→α + γ2 during the cold spraying. Compared with the Mg–Li alloy substrate, the aluminum bronze coating exhibits the higher microhardness (222.88 HV0.3) and wear resistance (friction coefficients, wear track widths and wear mass losses are 0.37, 0.79 mm and 2.47 mg, respectively). The dominant wear mechanism of the coatings was abrasive wear. In the electrochemical test, the corrosion current density of the aluminum bronze coating (3.07 × 10−5 A/cm2) was an order of magnitude lower than that of Mg–Li alloy substrate (6.15 × 10−4 A/cm2), indicating that the coating had superior corrosion resistance. The above analysis confirms that preparing a cold sprayed aluminum bronze coating has outstanding tribological and corrosion resistance properties.

Experimental investigation on anti-wear coating design for a small aviation kerosene piston engine

The high temperature wear failure of piston-cylinder system is a severe threat to aviation kerosene piston engines. To design a suitable anti-wear coating for the cylinder wall of a small aviation kerosene piston engine, a face contact friction pair and a line contact friction pair were designed to model the friction between the piston and the cylinder wall and the friction between the piston ring and the cylinder wall, respectively, and the graphite coating, the hard anodized coating (HA coating) and the microarc oxidation coating (MAO coating) were prepared on the cylinder wall specimen. Wear tests under high temperature were conducted for both friction pairs, and the friction coefficients, wear mass loss and worn surface morphology were analyzed. The results show that under high temperature condition, the graphite coating shows the least improvement on the wear mass loss and the worn surface state, the MAO coating causes serious wear to the piston specimen of face contact friction pair, while the HA coating is recommended as a suitable anti-wear coating for the engine by effectively reducing the wear mass loss and improving the worn surface state in both line contact and face contact friction pairs.

Effect of SiC Nanoparticles on AZ31 Magnesium Alloy.

Magnesium alloys are attractive for the production of lightweight parts in modern automobile and aerospace industries due to their advanced properties. Their mechanical properties are usually enhanced by the incorporation with reinforcement particles. In the current study, reinforced AZ31 magnesium alloy was fabricated through the addition of bulk Al and the incorporation of SiC nanoparticles using a stir casting process to obtain AZ31-SiC nanocomposites. Scanning electron microscope (SEM) investigations revealed the formation of Mg17Al12 lamellar intermetallic structures and SiC clusters in the nanocomposites. Energy dispersive spectroscopy (EDS) detected the uniform distribution of SiC nanoparticles in the AZ31-SiC nanocomposites. Enhancements in hardness and yield strength (YS) were detected in the fabricated nanocomposites. This behavior was referred to a joint strengthening mechanisms which showed matrix-reinforcement coefficient of thermal expansion (CTE) and elastic modulus mismatches, Orowan strengthening, and load transfer mechanism. The mechanical properties and wear resistance were gradually increased with an increase in SiC content in the nanocomposite. The maximum values were obtained from nanocomposites containing 1 wt% of SiC (AZ31-1SiC). AZ31-1SiC nanocomposite YS and hardness were improved by 27% and 30%, respectively, compared to AZ31 alloy. This nanocomposite also exhibited the highest wear resistance; its wear mass loss and depth of the worn surface decreased by 26% and 15%, respectively, compared to AZ31 alloy.

Effect of ultrasonic surface rolling process on the surface properties of QAl10-3-1.5 aluminum bronze alloy

The main purpose of this article is to study the effect of ultrasonic surface rolling process (USRP) on the surface properties of QAl10-3-1.5 aluminum bronze alloy under different rolling reduction and rolling times, providing ideas for improving the poor wear resistance of valve stem nuts and sealing rings. SEM, EDS and optical three-dimensional profiler were used to characterize the microstructure characteristics of the surface modified layer and the surface morphology of the wear traces. The results show that the surface layer of the USRPed sample has undergone severe plastic deformation. The α phase is elongated, and the microstructure structure shows a fine and uniform distribution state. And the grain size of α phases decreased, and the number density of β phases increased. Compared with the untreated sample (only cutting and polishing), the surface roughness of the USRPed sample reaches nearly Ra 0.04 μm; the maximum surface micro-hardness is 323.04 HV, increasing by 75%; the maximum depth of surface hardening layer is about 570 μm. The friction coefficient, wear mass loss and the width and depth of the wear traces of the USRPed samples are significantly reduced, while the wear resistance is significantly enhanced. By comparing the surface wear morphology of the samples under different process parameters, it is found that the main wear mechanism of the untreated samples is adhesive wear, while the main wear mechanism of the USRPed samples is abrasive wear. The improvement in wear resistance is attributed to the refined and homogenized surface microstructure, the smaller surface roughness, the larger surface micro-hardness and surface hardness layer depth after USRP.

A robust hybrid generator for harvesting vehicle suspension vibration energy from random road excitation

Existing energy harvesters are mostly designed into the electromagnetic shock absorbers to replace the original dampers in automotive suspension systems, possibly deteriorating sprung mass acceleration when the energy harvesters are in trouble. Therefore, this study proposed a hybrid generator based on the sliding-mode triboelectric nanogenerator (S-TENG) and electromagnetic generator (EMG) to harvest the suspension vibration energy without replacing the original damper and deteriorating sprung mass acceleration. First, the patterned polyimide (PI) films were prepared to solve the challenge of the poor durability of the S-TENG due to material wear. The results showed that the wear mass loss of PI film diminished with the decrease of pillar pitch, and the wear mass loss of P2 film was only 37% of that of the smooth one. Furthermore, whether the patterned surface could improve the electrical output of the S-TENG depended on the pattern parameters, which was a departure from the common view that any pattern could enhance triboelectrification. In this paper, P2 was the optimal textural parameter for improving the durability and electrical output of the S-TENG, which could provide a texture design reference for the S-TENG. Second, the hybrid generator charged a 4.7 μF capacitor to 18.05 V in 60 s, and the contribution ratio of charging voltage of the S-TENG component increased with extended charging time. Finally, the hybrid generator moved together with the original shock absorber without a noticeable impact on sprung mass acceleration, which can make the accelerometer self-powered at different random road excitations.

Study on wear behavior of low nickel austenitic stainless steel by using ball on disc

Austenitic stainless steels have wide applications in various industries due to its good corrosion characteristics and their surface strength. A variety of procedures are used to enhance the surface characteristics. Wear studies are critical in all of the toughest materials. Surface damage was studied in terms of material-removal methods such plastic deformation and brittle fracture. This paper investigated the specific wear rate of Low Nickel ASS. The parameters selected for wear testing like sliding speed, load, time duration and types of ball. Six numbers of experiments were conducted for measuring specific wear rate, mass loss and coefficient of friction were highlighted in this paper. A comparison study was made to know the effect of wear parameters like sliding speed, load, time duration and types of ball on specific wear rate and coefficient of friction. It was seen that with increasing of load and sliding speed of disc the specific wear rate of the material significantly increasing.SEM analysis was also made on worn surface to know the behaviour of wear in the sample.

Effects of different cooling conditions on friction stir processing of A356 alloy: Numerical modeling and experiment

In the present work, the effects of in-process cooling are investigated on the material flow, temperature distribution, axial force, wear resistance, and microstructural and mechanical properties of friction stir processed (FSPed) Al-Si aluminum alloy. The finite element method (FEM) was developed for modeling the process, based on the eulerian-lagrangian technique, and then verified by the experimental force and temperature histories. Next, the material flow and temperature distribution during the friction stir process (FSP) with in-process cooling under different conditions were considered. After that, the experimental investigations, including the optical microscopy, hardness, and wear tests, were conducted. Finally, the stir zone (SZ) shape obtained by experiments and simulation model were compared for the FSPed samples without cooling and with air cooling. The material flow achievements reveal that using a coolant affects the material flow in the pin-driven zone more significantly than in the shoulder-driven zone, leading the SZ to change from the basin shape into the V shape. The SZ shapes obtained from the experiments and the simulation model show a good agreement between the shapes of the samples FSPed without cooling and with air cooling. Moreover, experimental results showed that using in-process cooling reduces Si particles' size and thus significantly increases the hardness and wear resistance. The Si particles size is reduced from 10 μm in the base metal to 2.6 μm and 2 μm in the air-cooled and water-cooled samples. Consequently, the wear mass loss reduced almost 28% and 40%, and hardness increased almost 35% and 80% for the air-cooled and water-cooled samples compared to the processed samples without coolant.

Microstructure and Wear Property of ZrO2-Added NiCrAlY Prepared by Ultrasonic-Assisted Direct Laser Deposition.

For improving the wear properties of NiCrAlY, the 10 wt %, 20 wt % and 30 wt % ZrO2-added NiCrAlY samples were prepared by ultrasonic-assisted direct laser deposition, respectively. The results showed that the ultrasonic-assisted direct laser deposition can realize the ZrO2-added NiCrAlY preparation. Furthermore, due to the cavitation effect and agitation of the ultrasound in the molten pool, ultrasonic-assisted could make the upper surface of the samples smoother and flatter, and it also improved the microstructural homogeneity. The microstructure was mainly composed of columnar dendrites, and most of ZrO2 particles were located in the intergranular regions. The principal phase constituents were found to contain γ-Ni and t-NiZr2, and the amorphous (Ni, Zr) intermetallic phase generated, because of more rapid solidification after ultrasound assisted. The microhardness was improved slightly with the increase of ZrO2 contents, rising from 407.9 HV (10% ZrO2) to 420.4 HV (30% ZrO2). Correspondingly, wear mass loss was decreased with the maximum drop 22.7% of 30% ZrO2 compared to that of 10% ZrO2, and wear mechanisms were mainly abrasive wear with slightly adhesive wear. After applying ultrasound, the oxide islands in samples disappeared, and more ceramic particles were retained. Thus, the hardness and wear performance of the samples were improved.