Sliding Wear Tests Research Articles

The investigation of the effect of nano particles on dry sliding wear and corrosion behavior of Al-Mg/Al2O3 composites

Aluminum matrix composites were extensively used as structural material as it possesses good surface properties such as wear and corrosion resistance. The practical importance of nano particles in composite materials has triggered widespread attention towards the enhancement of its properties. In this study, Al-Mg/Al2O3 (0–8 wt%) metal matrix nano composites fabricated by two step stir casting route was investigated to comprehend its wear and corrosion behaviour. The Pin-on-Disc dry sliding wear test was performed on Al-Mg/Al2O3 (0–8 wt%) by adopting Design of Experiments under the action of different contact loads and sliding distance following the ASTM G99 Standard. The experimental results conveyed that specific wear rate decreases with increase in sliding distance. Statistical analysis was performed by Taguchi’s Technique and Analysis of Variance (ANOVA) to determine the most dominating factor that influences specific wear rate for the optimum weight percentage of reinforcement. Analysis revealed adequacy with the constructed model in predicting the wear behavior of composite and unreinforced Al-Mg alloy. The corrosion behaviour of the base alloy and composites was analysed by static immersion and electrochemical assessments, by immersing prepared specimens in aqueous sodium chloride (3.5%) solution. The dependance of corrosion rate of the composites with the weight percentage of Al2O3, exposure duration and temperature of the corrosive medium was studied in detail. Corrosion test results exhibit that corrosion rate decreases with increase in weight percentage of Al2O3 particles and exposure duration, whereas it follows reverse trend with increase in corrosion medium temperature.

Synthesis and characterization of (HfMoTiWZr)C high entropy carbide ceramics

(HfMoTiWZr)C high entropy carbides (HEC) were prepared from the commercial carbide powders of IVB (Hf, Ti, Zr) and VIB (Mo, W) group metals of the periodic table via high energy ball milling (HEBM) and spark plasma sintering (SPS). Metal carbide powders (HfC, TiC, ZrC, Mo2C and WC) were HEBM’d for 3 h in a vibratory ball mill, and then SPS’d at different temperatures (1800, 1900, 2000 and 2100 °C). The HEBM’d powders and SPS’d ceramics were characterized in composition, density and microstructure using an X-ray diffractometer (XRD), a scanning electron microscope/energy dispersive spectrometer (SEM/EDS), a particle size analyzer and a pycnometer. Also, microhardness and sliding wear tests were conducted on the SPS’d ceramics. Based on the performed characterization, a single-phase FCC structure was observed at all sintering temperatures indicating a high entropy carbide ceramic, and they all have high hardness and wear resistance values.

Comparative investigation of tribological behavior of hybrid dental restorative composite materials

Dental restorative composite materials require appropriate tribological characteristics to bear different stresses in the oral environment. This study inspects the tribological aspects of micro-nano parttticulate filled dental restorative composite materials. Nano-hydroxyapatite (nHA) (0, 2, 4, 6, and 8 wt%), alumina (20 wt%), and titanium oxide (20 wt%) were reinforced in the form of hybrid into the dental resin matrix. The dental resin matrix was fabricated from a base monomer, diluents, initiator, and accelerator. Two body sliding wear tests were conducted by rubbing the prepared nano-composites against a Carbon steel-EN 31 counter plate. ANOVA was used to find significant statistical factors. Besides, the wear mechanisms were clarified via scanning electron microscopy. EDS (energy dispersive spectroscopy) analysis was also done to identify the organic and inorganic groups incorporated in the dental composite samples. The results showed that incorporating high amounts of nHA nanoparticles can improve the wear properties of dental composites. The results of specific wear rate were found significant as per literature.

Wear behavior of silica-infiltrated monolithic zirconia: Effects on the mechanical properties and surface characterization

The objective of this study was to assess the wear behavior and its effects on the flexural strength of silica-infiltrated zirconia compared to glaze and polishing finishing treatments. To do so, disc-shaped samples of a second-generation zirconia were prepared and divided into three groups: silica infiltration, glazing, or polishing. Half of the samples of each finishing were subjected to sliding wear testing using a steatite antagonist. The discs and antagonists had their volume loss measured. The wear-tested and the other half of samples were subjected to biaxial flexural strength testing and the following characterization analyses were also performed: roughness, hardness, X-ray diffraction, profilometry, and scanning electron microscopy (SEM). Data were evaluated with ANOVA and Weibull analyses. Glazing caused greater antagonist volume loss, followed by silica infiltration, and polishing. Silica-infiltrated zirconia surface was similarly worn to polished, which was lower than that for glazed zirconia. Polished zirconia presented the highest flexural strength. However,the strength decreased and became similar in all worn groups. Silica infiltration showed slightly lower characteristic strength after sliding wear. The highest roughness and hardness values were observed on glazed zirconia. These values decreased after wear testing and became similar to the other groups. SEM evidenced an irregular surface for glazing. No phase transformation occurred after sliding wear. Despite producing some volume loss on zirconia and antagonist surfaces, silica infiltration is a promising alternative for finishing monolithic restorations. Moreover, the damage caused by sliding wear leads to decreasing the strength of zirconia regardless of the surface finishing.

Mechanical properties and tribological performance of A356/Cr3C2-NiCr surface composite developed by high-velocity oxy-fuel and post friction stir processing treatment

High-velocity oxy-fuel thermal spraying and post friction stir processing (FSP) techniques were utilized to fabricate a new lightweight metal matrix composite for industrial application in which A356 aluminum (Al) cast alloy and Cr3C2-NiCr were the matrix and reinforcements, respectively. The microstructure of the BM, friction stir processed samples, and composites were evaluated using optical microscopy and scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy. The investigations demonstrated that the coarse eutectic silicon blades were crushed to fine particles after FSP and the Cr3C2-NiCr coating were uniformly dispersed into the base metal (BM). The hardness of the samples was measured via microhardness and nanoindentation tests, which indicated a significant improvement (about twice the BM) in the hardness of the 4-pass friction stir processed composite. Considering the results of the uniaxial tensile test, the FSP enhanced the yield strength (YS) and ultimate tensile strength (UTS) of the samples. The YS and UTS of the 4-pass friction stir processed composite were nearly 53 and 22% higher than those of the BM, respectively. To study the tribological performance of the samples, the dry sliding wear test was conducted on the samples using a reciprocal wear machine. The results showed that the wear and friction performances of the composites improved dramatically (∼98% and 61% decrease in the wear rate and friction coefficient, respectively). Finally, the SEM investigations from the fracture surfaces, worn surfaces, and debris resulting from the wear tests were conducted on the samples to understand the fracture and wear mechanisms.

Computing the dynamic friction coefficient and evaluation of radiation shielding performance for AISI 304 stainless steel

The cold rolling deformation (CRD) has been employed to produce the different AISI 304 stainless-steel (AISI 304 S) samples containing different percent of the martensitic phase. The microstructure observations have appeared the different percentages of the martensitic phase included in the austenitic phase. The hardness amelioration mainly relied on the character, growth, and distribution of the martensitic phase. Additionally, the findings of wear tests clarify that the sliding wear rate decrease with the increase of the martensite phase. The worn surfaces have revealed the debris mechanism associated with delamination spots is predominant during wear tests. Also, the present study extends to evaluate the dynamic friction coefficients (μ) using temperature-time curve throughout performing the dry sliding wear tests. The comparison of measured and computed values of μ has revealed the good agreement between both. Moreover, neutrons and gamma-rays shielding performance of AISI 304 S were studied using Monte Carlo (MCNP5) and WinXCom programs. The MCNP5 calculations were performed for neutrons in the energy range of 10−5 eV to 20 MeV. While the shielding parameters of gamma rays were done in the energy range of 0.015–15 MeV. The results of radiation shielding showed that the AISI 304 S owns a good shielding performance against neutrons and gamma-rays compared to previously published studies.

Tribological Characteristics Near Welding Limit for Petroleum Metal Pipelines

Welding process is one of the most widely applied processes in the industry. This is due to the ease of the process and it's a quantitative process. The addition of metallic powders to the welding area has not been widely emphasized as a solution to amelioration the tribology characteristic of the welding area therefore the effect of adding metallic powders (SnS nanoparticles) to the welding area on tribology properties was studied. This effect was studied at the values of coefficient of friction, coefficient of wear and wear rate by using the ring – on – disc sliding wear test equipment was used to study the tribological behavior of low carbon steel (A 106 grade B) as pure, 6010 welded and SnS- 6010 welded) under changing loads with constant velocity and in one hour for each run the dry condition at ambient temperature. The results show the coefficient of friction, coefficient of wear and wear rate increased with up load.

Friction and wear behavior of ultra-high molecular weight polyethylene/graphene nanoplatelets nanocomposite coatings at elevated temperatures

Ultra-high molecular weight polyethylene nanocomposite coatings reinforced with 1 wt.% graphene nanoplatelets were deposited on aluminum substrates. Sliding wear tests with a pin-on-disc configuration were conducted at different temperatures (25oC, 75oC, 90oC, 115oC, and 125oC) to evaluate the wear behavior of the coating at elevated temperatures. The ultra-high molecular weight polyethylene/1 wt.% graphene nanoplatelets nanocomposite coating showed an outstanding performance by passing the wear test without failing even until temperatures of 115oC as compared to the pure ultra-high molecular weight polyethylene coating which failed at a much lower temperature of 75oC, indicating an improvement in the operating temperature range of ultra-high molecular weight polyethylene by at least 44%.

Dry sliding wear and mechanical behaviour of selective laser melting processed 18Ni300 and H13 steels for moulds

In today’s manufacturing, selective laser melting (SLM) enables the production of 3D metal parts with innovative designs. However, this technique is still limited to certain materials due to residual stresses and cracking. The ultra-low carbon maraging steel 18Ni300 is a proven steel for SLM processing, while H13 steel still presents some challenges due to cracking and low wettability. These two steels are currently used in mould making due to their mechanical properties. Aiming to compare and better understand the behaviour of these two steels manufactured by selective laser melting, their mechanical performance and dry sliding wear were investigated.Both steels processed by SLM exhibited the expected yield stress and tensile strength values, suitable for mould making. Dry sliding wear tests performed using a pin-on-disc apparatus, where pins of steel were pressed against discs of polypropylene reinforced with 40 wt% short E-glass fibres, showed that the H13 steel had a specific wear rate two orders of magnitude lower than the 18Ni300 steel (0.11 × 10-7 mm3/m.N). The wear mechanism of the 18Ni300 steel is abrasion, while fatigue plays the main role in the H13 steel.The results of this work allow to establish a correlation between the obtained microstructure, mechanical behaviour and tribological performance of both steels under the tested conditions and show that the H13 steel, processed by SLM, can be a good choice for the critical zones of moulds where a higher wear resistance is required.

The Mechanical properties and tribological behavior of Ni coated carbon fibers reinforced with Al 7075 metal matrix composites

The carbon fibers (CF’s) are preferred material whose usage has been very widely growing in various industries that are synthesizing novel composites because it exhibits superior properties. Researchers worldwide are focussed on improving the mechanical performance of the composites reinforced with carbon fibers. In the present work nickel coated carbon fibers were reinforced with Al7075 via stir casting metallurgy followed tensile, hardness and wear studies. The specimens with 0%, 1%, 2%, 3% CF’s reinforced composites were fabricated and subjected to tests as per the ASTM standards, the tension test showed that the tensile strength was increased by 26% the composite hardness was high as 79 BHN as compared with ascast alloy. The Tribological studies were carried out, the sliding wear test results revealed that the wear rate was increased with the increase in the sliding distance.

Tribological behavior of cold-sprayed titanium/baghdadite composite coatings in dry and simulated body fluid environments

This study reports the tribological behavior of Titanium/Baghdadite cold sprayed composite coatings for artificial human joints in a dry and simulated body fluid environments. Sliding wear tests are performed using a wear test rig to predict the wear resistance of the coatings. An in-depth analysis of the worn-out coatings is also done to establish the wear mechanism for the developed coatings. Scratch adhesion and wettability analyses of the composite coatings have also been reported. The role of microhardness and surface roughness on the performance of the cold sprayed composite coatings is also discussed. It is discovered that cold sprayed composite coatings successfully protect the biomedical grade steel from wear in dry and simulated body fluid environments. Three-body abrasion wear and adhesive wear are the dominant mechanisms observed behind the wear of these coatings. Coatings are found to adhere well with the substrate, and the critical loads for the coatings' delamination are also reported. Furthermore, the coatings are found to be hydrophilic in nature, and the hydrophilicity is observed to be improving with an increase in baghdadite content.

Analysis of tribological behaviour of aluminum‐titanium carbide‐basalt metal matrix composite

AbstractIn the recent years, particulate reinforced aluminum based matrix composites are playing an important role in automobile and aerospace applications due to their enhanced properties. In this work, an attempt has been made to optimize the tribological behaviour of aluminum 7075 matrix reinforced with titanium carbide (3 percent weight) and basalt particles (2 percent weight) using Taguchi based grey relational analysis. Composites are fabricated according to american society for testing materials standard using stir casting method dry sliding wear tests were carried out using pin on disc apparatus as per Taguchi's L9 orthogonal array. Grey relational analysis was used to obtain the optimum process parameters for multiple quality characteristics such as wear rate and coefficient of friction. Then significant contribution of wear parameters was determined by analysis of variance. A confirmatory test was carried out to validate the test result. Finally, the micro structural investigation on the worn surfaces was performed by scanning electron microscope.

Study for Improvement in the Surface Properties and Wear Behavior of Mild Steel

Abstract: Surface of a material can be improved by depositing the filler metal for the enhancement of various properties. Surface should be harder than substrate material for surface improvement. This surface improvement is also known as surfacing. In present research Mild steel specimens of size 140×35×40 were used to deposit surfacing layers and study the feasibility of iron/aluminum with varying compositions on low carbon steel deposited by GTAW process. Specimens for hardness and oxidation resistance were prepared. While studying oxidation of surfaced and un-coated area (base material), oxidation test resulted that the oxidation occurred on surface of base metal (un-coated area) after heating at different temperatures and time intervals. Specimens kept at 500˚C, 700˚C temperatures for 3, 6, 9 hours to get oxidized from un-coated surface but no mark of oxidation and pitting was visible at surfaced area but pitting of un-coated area occurred at 700˚C temperature. Oxidation had no effect to surfaced area. Low temperature oxidation test specimens gave only weight loss from un-coated portion but high temperature oxidation gave high amount of weight reduction due to pitting occurred on un-coated portion. The amount of weight loss of specimens increased with increase in furnace holding time at constant temperature. With increase in temperature oxidation of un-coated area of specimens also increased and pitting action occurred on un-coated area of specimens at high temperature. Further, for the various wear tests the cylindrical pins of 8 mm diameter with spherical tip 4 mm radius was made. Wear tests were carried out on pin on disc sliding wear testing machine. The comparison of wear rate loss was studied with constant sliding distance, varying load and sliding velocity of different compositions of iron/aluminum surfacing and substrate material. Hardness and wear resistance of composition were increased with increase in percentage of Fe element in composition. Composition C1 (Fe:Al/70:30) had high hardness and high wear resistance as compared to composition C2 (Fe:Al/30:70) and C3 (Fe:Al/50:50). Composition C3 (Fe:Al/50:50) had better hardness and wear resistance as compared composition C2 (Fe:Al/70:30). Keywords: Surface improvement, Fe-Al intermetallic, GTAW process, Sliding wear.

EFFECT OF LASER POST-TREATMENT ON MICROSTRUCTURAL AND SLIDING WEAR BEHAVIOR OF HVOF-SPRAYED NiCrC AND NiCrSi COATINGS

In this study, NiCrC and NiCrSi coatings are deposited on the MDN 310 steel using High-Velocity Oxy-Fuel (HVOF) process. Laser Surface Melting (LSM) post-heat treatment is carried out on as-sprayed coatings using Laser Engineered Net Shaping (LENSTM) with a power of 300[Formula: see text]W. The characteristics of both coatings in terms of mechanical and metallurgical properties have been investigated. The thicknesses of the as-sprayed NiCrC and NiCrSi coatings are in the range of 170–200[Formula: see text][Formula: see text]m. Laser-treated NiCrC and NiCrSi coatings exhibit a thickness range of 162–185[Formula: see text][Formula: see text]m, respectively. The microstructure of laser-treated NiCrC-300W coating clearly shows a dendrite-like structure, whereas the laser-treated NiCrSi coating exhibits hard layer and columnar homogeneity. Microhardness of as-sprayed NiCrC coating is [Formula: see text] [Formula: see text] and that of NiCrSi coating is [Formula: see text] HV[Formula: see text]. Microhardness of laser-treated NiCrC coating is [Formula: see text] HV[Formula: see text] and that of NiCrSi coating is [Formula: see text] HV[Formula: see text]. Dry sliding wear tests are conducted at room temperature (RT) and 400∘C with 10-N and 20-N loads. The wear rates at 400∘C temperature of laser-treated NiCrC and NiCrSi coatings produced are slightly below [Formula: see text][Formula: see text]mm3/m and [Formula: see text][Formula: see text]mm3/m, respectively. Laser-treated coatings produced better dry sliding wear behavior compared with as-sprayed coatings owing to dense microstructure. Formation of SiC phase in NiCrSi coating imparts high wear and frictional resistance compared to the NiCrC coating.

Effect of Reinforcements on the Sliding Wear Behavior of Self-Lubricating AZ91D-SiC-Gr Hybrid Composites

This article statistically investigates the effect of various parameters such as material factors: silicon carbide (SiC) reinforcement, graphite (Gr) reinforcement and mechanical factors: normal load, sliding distance and speed on the sliding wear rate of vacuum stir cast self-lubricating AZ91D-SiC-Gr hybrid magnesium composites. The sliding wear tests have been performed on pin-on-disc tribometer at 10-50N loads, 1-3m/s sliding speed and 1000-2000m sliding distance. It has been examined that hybrid composites yielded improved wear resistance with reinforcement of SiC and solid lubricant graphite. ANOVA and signal-to-noise ratio investigation indicated that applied load was the most critical factor influencing the wear rate, followed by sliding distance. Further, the AZ91D/5SiC/5Gr hybrid composite has exhibited the best wear properties. From the SEM and EDS analysis of worn surfaces, delamination was confirmed as the dominant wear mechanism for AZ91D-SiC-Gr hybrid composites.

Development and performance analysis of wear resistant polypropylene composites filled with micro sized Linz–Donawitz sludge particulates

Integrated steel plants, in general, produce large amounts of solid wastes during the production of iron and steel. Linz–Donawitz sludge (LDS) is an industrial solid waste generated in huge quantities during steelmaking. These fine solid particles were recovered after wet cleaning of the gas emerging from LD converters. This work aims at processing, characterization, and wear response of a class of polypropylene composites utilizing LDS as a filler material. Mechanical properties of these thermoplastic composites were evaluated under standard test conditions. The actual and the theoretical density values of the polypropylene-LDS composites were measured using Archimedes’ principle and rule of mixture respectively. The micro-structural features of the worn surfaces of various particulate filled composite specimens were examined using scanning electron microscopy in order to ascertain the wear mechanisms. X-Ray Diffraction analysis was carried out to determine the phases and planes of the components present within a material. Sliding wear tests were conducted using Taguchi’s L25 orthogonal arrays over a range of sliding velocities (0.63–3.15 m/s), normal loads (5–25 N), sliding distances (500–2500 m), and LDS contents (0–20 wt.%). The sliding wear tests were performed on the prepared polypropylene-LDS composite specimens as per ASTM G99 using Taguchi’s Orthogonal Arrays followed by the parametric appraisal of the wear process by response surface methodology (RSM). Both Taguchi analysis and RSM suggest that the filler content and the sliding velocity are the most significant factors affecting the specific wear rate of the composite specimens. This work opens up a new avenue for the utilization of LD sludge as a potential filler material.

Investigating load-dependent wear behavior and degradation mechanisms in Cr3C2–NiCr coatings deposited by HVAF and HVOF

Wear resistant coatings that comply with non-toxic environment goals are highly desirable. Cr3C2–NiCr is a promising alternative to the toxic, ‘Co’- containing WC–Co coatings to mitigate wear. The purpose of this study was to examine the suitability of Cr3C2–NiCr coatings for automotive brake disc application by systematically investigating their dry sliding wear behavior at different test conditions. Therefore, High Velocity Air Fuel (HVAF) and High Velocity Oxy Fuel (HVOF) were employed to deposit Cr3C2–NiCr coatings. The powder feedstock and as-deposited Cr3C2–NiCr coatings were characterized for their microstructure and phase composition using SEM and XRD. Mechanical properties (hardness, fracture toughness), porosity and surface topography of the as-deposited coatings were evaluated. The coatings were subjected to sliding wear tests at different normal loads (5 N, 10 N and 15 N) using alumina ball as the counter surface. Coefficient of friction (CoF) evolution of HVAF and HVOF deposited coatings, along with their wear performance, was obtained for different normal load conditions. The wear performance ranking of HVAF and HVOF processed coatings was influenced by the test conditions, with HVAF coatings demonstrating better wear resistance than HVOF coatings at harsh test conditions and the HVOF coatings performing better under mild wear test conditions. Detailed post-wear analysis of worn coatings, the alumina ball counter-body and the resulting debris was performed to reveal the degradation mechanisms at different test conditions. Findings from this work provide new insights into the desirable microstructural features to mitigate wear, which can be further exploited to deposit wear-resistant coatings.

The influence of cementite spheroidizing duration on the microstructure and sliding wear response of grey cast iron against AISI 4330

The present study investigates the sliding wear properties of G350 grey cast iron following various spheroidizing annealing durations. The annealed samples were used as pins in sliding wear tests against AISI 4330 discs. Most testing combinations resulted in mild wear with little matrix damage to the cast iron pin or AISI 4330 disc. A transition to severe wear was observed for the highest load and longest annealing times where the overly spheroidized and ferritized cast iron matrix deformed significantly, prohibited beneficial oxidative wear from occurring, and thus damaged its disc counterpart. The depth of subsurface deformation increased with annealing time but not load. Instead, the depth peaked at 4 kg applied load for each condition due to the spallation of the affected surface layer at the higher load.

Wear behavior of A356/ Al2O3/MoS2 hybrid nanocomposites

A356 composites with alumina and molybdenum disulfide nanoparticles are a distinct category of engineered materials developed for tribological use. This evolution has led to an attempt to investigate the microstructure and wear behavior of A356 hybrid nanocomposites reinforced with nano Al2O3 (0.5, 1, and 1.5 wt% of Al2O3) and nano MoS2 (0.5 wt% of MoS2) is fabricated by stir casting technique. Wear behavior of A356/ Al2O3/ MoS2 nanocomposites was tested by using the pin on disc equipment. The sliding wear tests were carried out at 10–50 N normal load insteps of 10 N, 2 m/s sliding velocity and 1000–5000 m sliding distance insteps of 1000 m/s. Results have shown that the increase of alumina and the addition of MoS2 nano particles have a positive impact on the improvement of tribological properties of the hybrid nanocomposites. The coefficient of friction and wear rate of hybrid nanocomposites are reduced with the addition of Al2O3 and a solid lubricant MoS2 particle.

Wear Behaviour of N Ion Implanted Ti-6Al-4V Alloy Processed by Selective Laser Melting

Selective laser melting (SLM) is a laser-based powder bed fusion additive manufacturing technique extensively used in industry. One of the most commonly used alloys in SLM process is Ti-6Al-4V. However, its tribological properties when coated with N ion implantation is not well understood. In the ion implantation process used in this study, N2+ and N+ are accelerated to the energy of 60 keV and implanted to a fluence of 6 × 1017 at.cm−2. The effect of N ion implanted layer in terms of hardness values and how this implanted layer may affect wear process and wear rate is investigated in this paper. Sliding wear tests were conducted on SLM and conventionally processed samples implanted with N ions, followed by examining the wear tracks and coefficient of friction in order to explain the wear rate data obtained. The results showed that N+ implantation increased hardness within the depth of ~200 nm and reduced wear rate in SLM samples, while N2+ was not beneficial.