Dry Sliding Wear Characteristics Research Articles

Stir‐cast Al2024‐based composite reinforced with boron carbide and graphene particles: Mechanical and dry sliding wear characteristics

AbstractBecause of its improved formability, lower production costs, and mechanical properties, aluminum metal matrix composite is the highly intriguing engineering material. It can meet the needs of modern engineering applications used in the automotive, military, aerospace, and marine industries. Hybridization of reinforcement is adopted to develop tailor‐made properties of composites for specific application. In this study, Al‐B4C‐Gr hybrid composites were produced with varying graphene content (0.25, 0.50, 0.75, and 1 wt.%) and keeping boron carbide (10 wt.%) as constant, the effect of graphene proportion on the mechanical properties of produced composites was evaluated. It has been observed that increasing the Gr reinforcement particles in the synthesized composites improves the mechanical characteristics of the composites, such as raising the tensile strength to 215 Mpa and the hardness to 110 HV due to the presence and proper distribution of reinforcement in the matrix. When compared to the base alloy, the tensile strength and hardness of Al10B4C0.75Gr composites rose by 27.174% and 67.290%, respectively. The dry sliding wear behavior of Al‐10 wt.% B4C‐wt.%Gr hybrid composites confirms that graphene and B4C particles in the matrix increase the wear resistance of the produced MMCs. The each parameter such as sliding distance, sliding velocity and load has its influence toward the better wear resistance of the developed composites and were discussed.

In vitro degradation and dry sliding wear characteristics of AZ31/TiO2 nanocomposites for biomedical application

This study concentrated on the degradation and wear characteristics of nanocomposites reinforced with (0, 0.5, 1.5 and 2.5 wt%) titanium dioxide (TiO2) nanoparticles on the AZ31 Mg alloy fabricated by the stir casting method. Optical microscopy and FESEM images showed that the TiO2 nanoparticles were distributed uniformly and the intermetallic phase Mg17Al12 observed along the grain boundaries. The surfaces of the nanocomposite samples was gradually covered with a magnesium hydroxide (Mg(OH)2) protective layer after 48 h of immersion in simulated body fluid (SBF). The immersed composite samples contained several white hydroxyapatite and magnesium phosphate particles. The addition of up to 1.5 wt% TiO2 nanoparticles reduced the degradation rate of the nanocomposites in SBF, while further addition increased it. FESEM images of the immersed samples revealed the presence of corrosion pits and cracks on the AZ31 alloy and its nanocomposites. Under dry conditions with varying loads, the wear characteristics of fabricated nanocomposites were studied using computerised pin-on-disc equipment. The addition of TiO2 nanoparticles up to 1.5 wt% improved the wear resistance of the nanocomposites. However, the further addition increased the coefficient of friction (COF) and wear loss due to agglomeration and porosity in the nanocomposites. The FESEM morphology of the worn surface and wear debris revealed that abrasion was the primary wear mechanism at low loads, and abrasion with severe plastic deformation and delamination were dominant at higher loads.

Novel study on investigating the mechanical, microstructure morphological, and dry sliding wear characteristics of grey cast iron GG25 with copper additions for valve guides in internal combustion engine

Introduction: The performance functionality efficacy of the engine’s valve train assembly is considerably affected by the valve guide. Material selection is impacted by the prolonged operational lifespan of engines, which favours casting and machining materials such as cast iron. The intent of this study is to examine the dry sliding characteristics of GG25 cast iron with copper additives. Discovering the ways in which variations in load and sliding velocity impact wear characteristics is of paramount significance.Methods: The research entailed the examination of wear characteristics across various environmental conditions. Loads were varied at 30 N, 40 N, and 50 N while maintaining a 1 m/s velocity constant. In the same manner, sliding velocities of 0.5 m/s, 1 m/s, and 2 m/s were varied while a constant load of 30 N was maintained. Experimental techniques were carried out at ambient temperature. Throughout the investigations, frictional forces and the coefficient of friction were also determined. The wear mechanisms of samples that had become deteriorated or worn-out were examined by employing a scanning electron microscope when combined with EDX analysis.Results: A rise in the normal load from 30 N to 40 N led to a twofold rise in wear losses, measuring 417 microns as compared with 222 microns previously. The range of wear losses observed at moderate speeds (0.5 m/s–1 m/s) was 133–222 microns. Conversely, the maximum wear loss observed was 1,226 microns at elevated sliding velocities of 2 m/s, in contrast to 617 microns at higher normal loads of 50 N. Additionally, the research discovered that normal load is more pronounced when both loading and speed are moderate, whereas sliding speed becomes more substantial when both are raised, culminating to higher wear losses.Discussions: In summary, the research highlights the considerable effect that normal load and sliding speed have on the prevalence of wear losses. In conditions of moderate loading and velocity, the influence of normal load is more significant. However, as sliding accelerates, it becomes the predominant factor. An analysis of frictional forces as well as the coefficient of friction indicated that under loading conditions of 30 N–50 N, the friction coefficient raised from 0.238 to 0.43. The wear mechanisms, as discerned via scanning electron microscopy and EDX analysis, underscored the considerable impact of increased sliding velocity on wear loss in comparison to conditions of higher loading.

Dry sliding wear characteristics of in-situ hybrid (Al3Ni + Al2O3)–Al composites

Dry sliding wear characteristics of in-situ hybrid (Al3Ni + Al2O3)/Al composites synthesised by solid-state combustion of Al– xNiO ( x = 8 wt%, 10 wt%, 12 wt% and 15 wt%) system were investigated. The results indicate that the in-situ hybrid Al3Ni + Al2O3 particles can markedly improve wear performance of composites. The increase of wear resistance with an increase in NiO content at room temperature can be attributed to high hardness offered by high volume fraction of hard Al3Ni and Al2O3 particles. While, at 200 °C, the increase in wear resistance of composites with higher NiO contents can be attributed to the high thermal stability of composites. With the increase of NiO content from 8% to 15%, the wear mode of composites also is discussed at room temperature and 200 °C.

Dry sliding wear characteristics of Al7075 alloy‐reinforced with SiC and cenosphere particles

AbstractAluminum metal matrix composite (AMMC) is employed in all engineering applications, most notably as a substitute for conventional metals in the fields of defense, automotive, and aerospace. AMMC should have a wide variety of structural, mechanical, thermal, wear, and corrosion qualities that may require mutually exclusive features at an optimal level to achieve this. The current research focuses on the stir casting process for producing SiC and cenosphere reinforced Al7075 alloys. The response surface method's (RSM) face‐centered central composite design (CCD) was used to design the number of experimental trials, and a response surface technique was enforced to forecast the optimum combination of processing variables in the wear process. The SiC reinforcement improved the wear resistance of Al7075‐SiC‐cenosphere composites substantially. Overall, the experiments show that Al7075‐6 wt% SiC‐5 wt% cenosphere has excellent tribological properties. The hybrid Al7075/SiC/Cenosphere composites were shown to be effective, fit, and suitable in the ideal wear process parameters (load of 10 N, sliding distance of 1000 m, and sliding velocity of 1.5 m/s) for lowering wear rate (0.38035 × 10−3 mm3/m) at 6wt% SiC reinforced composite. This suggests that the combination of SiC and cenosphere improves the wear resistance of AMMC.

Dry and Lubrication Sliding Wear Characteristics and Wear Mechanism Mapping for In Situ Al–25Mg2Si Composites

This study investigates the wear characteristics of Al–25Mg2Si composite synthesized via gravity casting. The research aims to understand the influence of applied load, test temperature, contact condition (dry and lubrication), and sliding distance on wear characteristics. Results show that higher loads and temperatures lead to increased wear loss and coefficient of friction. The worn surface morphology for higher loads and temperature shows deeper scratches and grooves, indicating severity in wear. The debris size and volume increase with an increase in load and temperature. The dominant mechanism is abrasive, adhesive, and oxidative for both the room‐ and high‐temperature dry sliding conditions. However adhesive and oxidative wear increase with the increase in test temperature. Abrasive wear is the only wear mechanism present during the lubricating sliding condition. Wear transition is noticed during the wear map analysis subjected to load, temperature, and sliding distance. In the case of room‐temperature test, severe–moderate–mild wear transition occurs with the increase in sliding distance and mild–moderate–severe wear transition occurs with the increase in test temperature and applied load. The roughness of the worn surface increases with an increase in applied load and temperature and the use of lubricant hugely reduces the surface roughness.

Ranking analysis of flyash – basalt fibre – polyamide 66 polymer composites based on the mechanical and sliding wear performance metrics using hybrid AHP-R method

This research work investigates the physical, mechanical, thermal, thermo-mechanical, and dry sliding wear characteristics of hybrid flyash particulates (F-class; 0 – 20 wt.% at the step of 5%)–basalt fibres (chopped; fixed 10 wt.%) reinforced polyamide 66 polymer composites fabricated using the twin screw extruder and injection moulding machine. Taguchi's design of experiment optimization approach is used for parameter optimization of the dry sliding wear process, followed by analysis of variance analysis. Further, the hybrid AHP-R method is used for ranking optimization based on the performance metrics. It is observed that the composition having 15 wt.% flyash particulates optimizes overall performance metrics, hence recommended for industrial parts fabrications. It has an experimental density of 1.23 g/cc, voids content of 5.93%, water absorption of 4.21%, tensile strength of 110.73 MPa, flexural strength of 146.72 MPa, Rockwell hardness of 62.44 HRM, fracture toughness of 4.17 MPa√m, impact strength of 2.06 J, the thermal conductivity of 1.24 W/mK, and specific wear rate of 7.55 × 10−4 mm3/Nm. The overall subjective ranking of the hybrid polymer composites attunes with the objective ranking by the hybrid AHP-R method.

Investigations of the wear and corrosion characteristics of Al-SiC-WC hybrid composites produced via stir casting

In this research, AA6061 T6 composites were manufactured using a stir casting technique reinforced with silicon carbide and tungsten carbide. Three distinct compositions of samples were created by altering the weight proportion of silicon carbide and tungsten carbide (0%, 4%, and 8%). The powders were subjected to SEM analysis and Laser Particle Size analysis, followed by planetary ball milling. EDX analysis and XRD analysis were conducted to verify the chemical composition of the particles. Dry sliding wear characteristics were tested using pin-on-disc equipment and wear morphologies were investigated using SEM. Wear rate measured as volume of stock removed per meter length was found to be 1.26 × 10−3 mm3/m for 8% reinforced composites compared to 2.56 × 10−3 mm3/m for the basic material. The aqueous NaCl spray method was adopted to examine the corrosion resistance behaviour of composites. The investigations on corrosion were analyzed with potentiodynamic studies and found that reinforced composites show resistant to corrosion. 8% SiC, WC reinforced composites show improved corrosion resistance compared with unreinforced alloy. The research data shows that the material can be produced and employed in automotive, aerospace, braking application, marine environments etc.

Wear surface characterization of hybrid Al alloy-based nanocomposites

Using liquid metallurgy route, an aluminumAl6061-1.2 wt% nanoSiC-0.5 wt% graphite hybrid nano-composites composite was fabricated. The dry sliding wear characteristics of thehybrid nano-compositeswere investigatedunder various sliding parameters using the pin-on-disc apparatus.The prepared hybrid nanocomposite were examined for wear surfaces by using the Field Emission Scanning Electron Microscope (FESEM)and 3Dprofilometer. Al/1.2SiC/Gr hybrid nano-composites performed better than the Al6061 matrix alloy in terms of wear resistance. The hybrid nano-composite wear surface roughness was 1.560 µm but the alloy matrix roughness was 6.20 µm at 0.5 m/s under 40 N. Comparing the Al/1.2SiC/Gr nanocomposites to the Al6061 matrix alloy, the surface smoothness was found to be the best.

Synergistic Effect of FSP and TiB2 on Mechanical and Tribological Behavior of AA2024 Surface Composites

Abstract In this research, AA2024 aluminum alloy-based surface composites were fabricated using ex situ titanium boride particles (TiB2) as reinforcement using the friction stir processing technique. Microstructural and mechanical variation with respect to the addition of TiB2 onto the AA2024 surface was studied and evaluated. Results proposed an increase in mechanical strength and hardness with respect to TiB2 addition when compared with the substrate metal. Dry sliding wear characteristics of aluminum surface composites at varying sliding distances (500 m, 1000 m, 1500 m, and 2000 m) were analyzed using pin on disc apparatus. Wear resistance of developed surface composites improved comparatively with respect to substrate metal due to the combined effect of particle inclusion and friction stir processing. Characterization of worn-out surface composites proposed that the wear mechanism happens due to the combination of abrasive and adhesive wear, while the major material removal happens due to abrasive wear.

Effects of Normal Load and Sliding Distance on the Dry Sliding Wear Characteristics of Invar-36 Superalloy

In the present study, the wear and friction behavior of Fe-based Invar-36 superalloy was investigated against an alumina ball under various sliding distances (25, 50, 75 and 100 m) and normal loads (5, 15 and 25 N) using a ball-on-disk tribometer. The worn surfaces were characterized using scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) and 2D-profilometry. The experimental results show that the coefficient of friction (COF) of Invar-36 (0.37-0.51) significantly decreased with increasing normal load, with a minimum value at 25 N. On the other hand, a slight increase in friction coefficient was observed with increasing sliding distance. Moreover, the wear volume of Invar-36 (ranged from 2.63 to 157.17×10-3 mm3) was observed to increase with increasing normal load and sliding distance. The specific wear rate found a constant increase from 1.98-2.99×10-5 to 6.33-11.45×10-5 mm3/Nm at increasing normal loads. On the contrary, the wear rate was gradually reduced when the sliding distance was increased especially at higher applied loads, due to the densification process. In addition, the wear mechanism was complex, including oxidation, adhesion and abrasion and plastic deformation, became more intense as the normal load or the number of sliding cycles was increased.

Effect of Alloying Elements on the Dry Sliding Wear Characteristics of Gravity-Cast Mg-Sn Based Alloys

Effect of Alloying Elements on the Dry Sliding Wear Characteristics of Gravity-Cast Mg-Sn Based Alloys

Dry sliding wear characteristics of natural fibre reinforced poly-lactic acid composites for engineering applications: Fabrication, properties and characterizations

Natural fibre composites have emerged as a viable alternative to conventional polymer composites, after environmental concerns gain popularity. In recent years, a tremendous growth in the applications of natural fibre composites have been observed, particularly in the field of construction, as well as aerospace and automotive industries. The present study investigates the feasibility of developing a novel tribo-material by reinforcing biopolymer with easily accessible and inexpensive plant fibres from the surroundings. The fibres were treated chemically prior to fabrication. The injection molding process was used to fabricate laminated composites by incorporating three different kinds of fibres (sisal, banana, and bagasse) into Poly-lactic acid (PLA) matrix at 10% and 20% fibre concentrations. Wear properties of fabricated composites were studied on a digital display controlled pin-on-disc test rig. The test parameters under dry sliding conditions were sliding distance (1000–3000 m), sliding speed (2,4 and 6 m/s) and applied load (10 N). The experimental results depict that the incorporation of natural fibres improved tribological properties of neat PLA matrix. The worn surfaces of developed composites were examined using a scanning electron microscope to study the wear mechanism.

Erosion and wear analysis of fly ash filled GFRP composite

The present work involves the solid particle erosion behaviour and the dry sliding wear characteristics of glass fiber reinforced polymer (GFRP) matrix composite using fly ash as filler material is investigated. Five different composite samples (with 0, 5, 10, 15 and 20 wt.% of filler) are fabricated using the traditional hand lay-up method and characterized for their density and hardness properties. Subsequently, the erosion and wear behaviour of the presently prepared composite samples are investigated on air erosion tester and pin-on-disc tribometer, respectively. For the erosion test experiments are performed according to a full-factorial design of experiment (DOE) by considering the hardness of the composite and the impingement angle as the controllable parameters. For conducting the dry sliding wear test, the type of composite, load and speed are taken as input parameters and the experiment is carried out as per Box-Behnken DOE of Response Surface Methodology (RSM). The composite with 15 wt.% of filler depicted the highest hardness value. The wt.% of filler is found to have a significant effect on the erosion and wear behaviour with moderate filler (10 wt.%) providing the optimum result in both cases.

Tribo-behavioural transition of Ti6Al4V as a function of sliding velocity and load under dry sliding conditions

ABSTRACT In this work, the dry sliding wear characteristics of Ti6Al4V (Ti64) – EN31 (steel) tribo-pair at incremental sliding velocity (SV, 0.838–1.466 ms-1) and load (L, 50–100 N) conditions are elucidated. As evident, specific wear rate (SWR) and coefficient of friction (CoF) increases and decreases, respectively with load and SV. The wear response of Ti64 undergoes a transition from composite type (oxidative and metallic) to delamination. The evolved oxides, viz. TiO and Ti8O15 were majorly in the form of free particulates. At low SV (0.838–1.047 ms-1) and low load (50–70 N), the movable particulates can activate a separation effect limiting the damage due to wear. During severe sliding (SV = 1.257–1.466 ms-1 and L = 70–100 N), the combined influence of frictional heating instigated thermal softening, and the formation/retainment of hard-coarse particulates at the interaction zone causes perforation into the substratum, assisting in spalling.

Моделирование характеристик износа при скольжении композиционного материала на основе политетрафторэтилена (ПТФЭ), армированного углеродным волокном, в паре трения с SS304 (12Х18Н10Т)

Introduction. Over the last decade, composite materials based on polytetrafluoroethylene (PTFE) have been increasingly used as alternative materials for automotive applications. PTFE is characterized by a low coefficient of friction, hardness and corrosion resistance. However, this material has a high wear rate. A group of researchers attempted to improve the wear resistance of PTFE material by reinforcing it with different fillers. The purpose of the work: This study experimentally investigates the dry sliding wear characteristics of a PTFE composite reinforced with carbon fiber (35 wt.%) compared to SS304 stainless steel. In addition, experimental mathematical and ANN models are developed to predict the specific wear rate, taking into account the influence of pressure, sliding speed, and interface temperature. The methods of investigation. Dry sliding experiments were performed on a pin-on-disk wear testing machine with varying the normal load on the pin, disk rotation, and interface temperature. Experiments were planned systematically to investigate the effect of input parameters on specific wear rates with a wide range of design space. In total, fifteen experiments were carried out at a 5-kilometer distance without repeating the central run experiment. Sliding velocities were obtained by selecting the track diameter on the disk and corresponding rotation of the disk. A feedforward back-propagation machine learning algorithm was used to the ANN model. Results and Discussion. This study finds better prediction accuracy with the ANN architecture having two hidden layers with 150 neurons on each layer. This study finds an increase in specific wear rates with normal load, sliding velocity, and interface temperature. However, the increase is more prominent at higher process parameters. The normal load followed by sliding velocity most significantly affects the specific wear rate. The results predicted by the developed models for specific wear rates are in good agreement with the experimental values with an average error close to 10%. This shows that the model could be reliably used to obtain the wear rate of PTFE composite reinforced with carbon fiber (35 wt.%) compared to SS304 stainless steel. This study finds scope for further studies considering the effect of varying ANN architectures, different amount of neurons, and hidden layers on the prediction accuracy of the wear rate.

Dry Sliding Wear Characteristics of NiP/TiN Duplex Coated Aluminum Alloy and Wear Analysis Using Response Surface Method

Dry Sliding Wear Characteristics of NiP/TiN Duplex Coated Aluminum Alloy and Wear Analysis Using Response Surface Method

Dry wear response of a Zn-based alloy containing 37.5% Al as affected by sliding conditions

Abstract This paper discusses the observations made pertaining to dry sliding wear characteristics of a Zn-based alloy at different sliding speeds and pressures. The wear rate increased with speed and pressure. The wear rate versus pressure plots attained two slopes wherein the slope was low up to a specific pressure followed by an increased slope at still higher pressures. This trend was observed at all the sliding speeds except the maximum; in the latter case one slope (identical to that of the higher slope at the lower speeds) only was noted. The seizure pressure was noted to decrease with speed. The temperature near the specimen surface increased with test duration, pressure and sliding speed. The rate of temperature increase was significantly high initially. This was followed by a lower rate of increase in temperature at longer test durations. In some cases, the rate of temperature increase became high once again towards the end of the tests. The influence of applied pressure and sliding speed on the temperature increase was practically identical to that on wear rate. Lower wear rate of the alloy agreed with less surface/subsurface damage and finer debris formation and vice versa.

Dry sliding wear characteristics, corrosion behavior, and hot deformation properties of eutectic Al–Si piston alloy containing Ni-rich intermetallic compounds

Al–Si eutectic alloys could be an alternative for gray and compacted graphite cast iron engine blocks due to their excellent thermal conductivity, low density (resulting in weight reduction and fuel efficiency), and good combination of strength and ductility. However, microstructural softening at service temperature (170–250 °C) due to coarsening/coalescence of metastable precipitates and low wear resistance are a stumbling block limiting their usage in engine components. To meet endless demands for fuel-efficient car engine (i.e. higher temperature and pressure in combustion chamber), optimization of current chemical composition seems to be essential. For this reason and in the present study, different concentration of Ni (from 0.8% to 3.5%) was doped into a eutectic Al–Si alloy to investigate tribological, corrosion, and hot deformation properties. It was pointed out that Al–Si eutectic alloy containing 2–2.6% Ni had the highest wear resistance due to uniform dispersion, skeleton-type morphology of Ni-rich intermetallic compounds, and their better bonding with the matrix. Oxidation and delamination of oxide layer was shown to be the main wear mechanism. The presence of (Ni,Cu)-rich intermetallic compounds increased the corrosion rate by ≈ 60%; however, the repassivation potential was found to be slightly higher in 2.6%Ni sample indicative of easier repassivation of micropits. To better understand the high temperature behavior of Ni-containing Al–Si alloy, hot compression test was carried out within the temperature range of 400–550 °C and strain rates of 0.001 to 1s−1 and constitutive equations were used to develop hot deformation processing maps. The presence of Ni-rich intermetallic compounds enhanced the hot deformation behavior and increased the activation energy for hot deformation. Dynamic recrystallization was found to be the main softening mechanism during hot deformation. At true strain of 0.6, the maximum power dissipation efficiency (≈54%) was obtained at 400 °C and a strain rate of 0.01s−1.

Effect of ultrasonic vibration treatment on microstructure and dry sliding wear characteristics of LM25 aluminum alloy

Grain refinement studies on Aluminum alloys with the addition of silicon, and magnesium alloys have fascinated considerable attention in the last five decades. Aluminum alloy properties of castings predominately depend on the grain structure formation that takes place inside the material meanwhile the solidification process. In the current investigation, a device has been designed and established to induce high-frequency ultrasonic vibrations to the molten metal at the time of solidification. This paper outlines Ultrasonic frequencies of varied were 10 to 50 kHz in the step of 10 kHz. The amplitude of the experiment was kept constant at 15 V for the entire findings. From the studies, it is found that the size of the grains has been reduced by 40% from coarse to fine equiaxed grains. Hardness value was noted with increased by 57.5% as well as Wear properties of treated LM25 alloy in dry sliding conditions have substantially improved. Wear studies has been carried out using standard pin on disc machine with various altered speeds. The study aims to validate that there are grain refinement and considerable improvement in the wear-resistant properties of the treated alloy.