Sliding Wear Behavior Research Articles

Sliding Wear Behavior of Intermetallic Ti-45Al-2Nb-2Mn-(at%)-0.8vol%TiB2 Processed by Centrifugal Casting and Hot Isostatic Pressure: Influence of Microstructure.

Intermetallic alloys such as titanium aluminides (TiAl) are potential materials for aerospace applications at elevated temperatures. TiAl intermetallics have low weight and improved efficiency under aggressive environments. However, there is limited information about wear behavior of these alloys and their microstructure. The present work aims to study the influence of the microstructure in the tribological behavior of TiAl intermetallic alloy (45Al-2Mn-2Nb(at%)-0.8 vol%TiB2). Wear tests were performed on samples manufactured by centrifugal casting (CC) and hot isostatic pressure (HIP). Reciprocating sliding wear test was carried out for TiAl, it was combined with different loads and frequencies. Wear tracks were analyzed through opto-digital microscopy and electron microscopy (SEM). The results obtained reveal that CC intermetallics present the lowest volume wear lost, approximately 20% less than HIP intermetallics. This good behavior could be related to the high hardness material, associated with the main microstructure where CC intermetallic has nearly lamellar microstructure and HIP intermetallics present duplex microstructure.

Effect of Temperature and Sliding Velocity on the Dry Sliding Wear Mechanisms of Boron Modified Ti-6Al-4V Alloys

The dry sliding wear behavior of as-cast pristine and boron-modified Ti-6Al-4V (Ti64) alloys (having 0.3 and 0.55 wt% B) is investigated using pin-on-disc experiments with the pin being Ti64 alloy and the EN31 steel disc. Experiments are performed at sliding speeds (s) of 1, 2, and 4 m/s and temperatures 300 and 573 K. A mixed response in wear behavior is observed. At the lowest sliding speed, all three alloys (except 0.55B alloy at 300 K) exhibit similar wear rates, with abrasive wear being the dominant wear mechanism. At 2 m/s, temperature and s increase, and adhesive wear takes over along with delamination wear. Here, the 0.55B sample shows the highest wear rate due to the debonding of more TiB particles, which increases three body abrasion wear. With further increase in s to 4 m/s, delamination and oxidation wear are observed for all the samples. XRD evaluation shows traces of TiO2 and Fe2O3, which imply the formation of MML in samples tested at s = 4 m/s, which is also validated through subsurface microstructure analysis. It is found that MML having more TiB particles has more stability, because of which 0.3B samples show higher wear rate.

Evaluation of Wear Behaviour Based on Mechanical Properties and Particle Size in LM26 MMC

Abstract Based on its superior casting and mechanical properties, LM26 is a well-known material in the automobile sector for the manufacturing of pistons for both diesel and gasoline engines. However, cast alloys diminishing the strength at higher temperatures leads to metal matrix composites. The present work deals with fabrication and characterisation of aluminium cast alloy LM26 reinforced with ceramic particles of Almandine Garnet with varying percentages fabricated by dual step stir casting technique The micro hardness and ultimate tensile strength (UTS) were determined and the sliding wear behaviour was estimated using a pin-on-disc apparatus. The effect of particle size and weight fraction of reinforcement on physical and mechanical properties were investigated and collated with unreinforced metal. Wear behaviour of the composite had a reasonably good correlation with composite mechanical properties were also observed. Validation of Experimental results with theoretical values were also discussed.

MECHANICAL AND TRIBOLOGICAL CHARACTERIZATION OF HYBRID Al6061/B4C/Gr COMPOSITES BY STIR CASTING TECHNIQUE

This research focuses on the fabrication of Al6061/B4C/Gr metal matrix composites as well as the mechanical and wear properties analysis. A liquid metallurgy stir casting process was used to cast the Al6061 alloy matrix composites with specific wt.% of B4C and constant wt.% of graphite. In this work, newly developed composites of Gr (particle grain size: 0–20[Formula: see text][Formula: see text]m) and B4C (particle grain size: 0–30[Formula: see text][Formula: see text]m) are reinforced with Al6061 pure alloy, which enhanced the mechanical and wear properties when compared to Al6061 pure alloy. Microstructure analysis was carried out concerning the developed mechanical properties. Furthermore, the dry sliding wear behavior of Al6061/B4C/Gr metal matrix composites was investigated at a sliding speed of 1[Formula: see text]m/s and a sliding distance of 1500[Formula: see text]mm against a hardened EN-31 disc under the corresponding load of 19.68[Formula: see text]N. The minimum wear rate is [Formula: see text][Formula: see text]mm3/m found at 15[Formula: see text]wt.% B4C and 2[Formula: see text]wt.% graphite and the coefficient of friction is 0.54 that decreases with graphite addition, with the lowest value obtained with 5[Formula: see text]wt.% B4C and 2[Formula: see text]wt.% graphite. Al6061/10[Formula: see text]wt.% B4C/2[Formula: see text]wt.% Gr particles-reinforced composite material demonstrated the highest tensile and flexural strengths. The hardness,compressive and tensile strength of the Al6061/15[Formula: see text]wt.% B4C/2[Formula: see text]wt.% Gr particles-reinforced composite material were the highest. Scanning electron microscopy was used to examine the worn surfaces of wear specimens. The main objective of this work is to develop hybrid Al6061/B4C/Gr composites with improved mechanical and wear properties when compared with the base alloy. Al6061 is widely used in automobiles parts like engine block, piston rings, alloy wheels, marine industries, etc. B4C used in the composite improves strength and is used commonly in armed bullet proof. The Gr present in the composite improves wear resistance, and therefore applied in wear-resistant parts like brake, piston with cylinder, etc.

Tribological performance of AZ91D/HfCp magnesium composite prepared through stir-ultrasonic-squeeze casting technique

The present work investigates the influence of hafnium carbide, an ultra-high temperature ceramic reinforcement on the dry sliding wear behaviour of AZ91D magnesium composite. AZ91D/5 wt.% hafnium carbide composite and AZ91D alloy were fabricated using stir-ultrasonic treatment-squeeze casting method followed by heat treatment (T6). Microstructure and intermetallic phase studies were performed using scanning electron microscopy and X-ray diffraction techniques. Density, porosity and hardness of the materials were determined. Wear tests at room temperature were conducted at various sliding speeds (0.25–1 m/s) and normal loads (12.5–50 N), using a pin-on-disc tribometer. The temperature of wear varied from 50–200 °C for high-temperature wear tests. Compared to alloy, the composite showed better wear performance under all test conditions. Increasing the normal load increased the wear rate of both materials, but the wear rate decreased with an increase in sliding speed. The friction at the sliding interface decreased with an increase in normal load and sliding speed. The mechanisms of wear for both materials were abrasion, delamination, and oxidation at room temperature. At high temperatures, there was a dramatic increase in the wear rate of the alloy at 150 °C, whereas the wear resistance of composites improved up to 150 °C due to the presence of small amounts of hafnium carbide ultra-high temperature ceramic reinforcement. Abrasion, oxidation, delamination, and plastic yield were the primary wear mechanisms at high temperatures.

Microstructural characterization and dry sliding wear behavior of boride layers grown on Invar-36 superalloy

Invar-36 is extensively used in fields where high corrosion resistance and dimensional stability are required. However, its hardness limits its use in tribological applications, such as in the manufacture of bulky composite tooling for the aerospace and automotive industries. In this paper, powder-pack-boriding is proposed for the production of the boride layer on Invar-36 superalloy at 975 °C for 5 and 7 h using the nano-sized boriding powder mixture of 90 wt% B4C and 10 wt% NaBF4 as a boron source. The grown boride layers were characterized using scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), X-ray diffractometry (XRD), 2D- and 3D-profilometry, microhardness measurements and ball-on-plate type wear tests. Microstructural characterization revealed a complex and homogenous boride layer mainly consisting of NiB, FeB and Fe2NiB phases with 176.9–189.1 μm thickness. The surface hardness of Invar-36 increased from 150.7 to 1109.5 HV0.05 after the boriding process. The improvement in surface hardness of the grown boride layer enhanced the wear resistance of the Invar-36 superalloy by 28.6–105 times.

Sliding wear behaviors of the AlNiTi amorphous coatings: effect of temperatures

High-temperature wear behaviors are of prime importance for broadening the application guidelines of the Al-based amorphous coatings. For this objective, the effects of ambient temperatures on tribological behaviors of the AlNiTi amorphous coatings were investigated from room temperature (RT) to 450 °C. The results showed that the wear rate for the coating slid at 300 °C declines by two orders of magnitude in comparison to 2219-Al and 7075-Al alloys due to high hardness, strain tolerance, and elastic recovery capacity. With increasing temperatures, friction coefficients decrease steadily as a result of the oxide tribo-films formed on the wear track. However, there is an initial decrease in wear rate up to the temperature of 400 °C followed by a slight increase after the full devitrified temperature. The coating shows superior wear resistance at an elevated temperature of 400 °C because of the remained amorphous structure and intact protective oxide tribo-film. The wear mechanism of the coating transfers from brittle spalling coupled with oxidation wear to oxidative wear with increasing temperature up to 400 °C. After full devitrified temperature, the formation of deformed layers beneath oxide tribo-film aggravates marginally the wear of the coating. The synergistic effects of structure evolution, high-temperature hardness, and oxidization on tribological behaviors were discussed. These current findings provide insights into the real applications of the AlNiTi amorphous coating at evaluated temperatures.

Dry Sliding Wear Behavior of Magnesium Composites with Ti3AlC2 Reinforcement: Tribological Responses and Underlying Mechanisms

Dry Sliding Wear Behavior of Magnesium Composites with Ti3AlC2 Reinforcement: Tribological Responses and Underlying Mechanisms

Sliding wear behavior of cold metal transfer cladded Stellite 12 hardfacings on martensitic stainless steel

Cold metal transfer (CMT) welding technique was used in the manufacturing of hypoeutectic carbide-type Co-based Stellite 12 hardfacings on martensitic stainless steel. It was discovered that the CMT process is capable of producing relatively thick (> 2.5 mm) low diluted single-layer coatings with cored Stellite 12 wire without cracks and pores. These coatings were investigated using microscopy (optical and scanning electron microscopy), X-ray diffraction, and hardness measurements. The high melting point chromium and tungsten particles inside the cored wire were relatively large and therefore remained unmelted in the clad layers. Self-mated sliding wear tests were performed using a pin-on-disc tribometer at room temperature and at 300 °C to determine the wear resistance and friction of the coatings. The coefficients of friction were relatively similar (~ 0.35) at both temperatures. Differences were exhibited in the ~ 40% greater loss of material at high temperature. The wear performance of the CMT clad Stellite 12 coatings did not, however, reach the wear performance of self-mated laser clad Stellite 6 reference material. CMT hardfacing was finally successfully demonstrated on a ring-shaped component.

High Hardness and Wear Resistance in AlCrFeNiV High-Entropy Alloy Induced by Dual-Phase Body-Centered Cubic Coupling Effects.

High-entropy alloys (HEAs) with high hardness are promising materials for advanced industrial manufacturing. In this study, the AlCrFeNiV HEA was designed and successfully prepared using a plasma instantaneous process. The hardness test showed that AlCrFeNiV had a high hardness of 1076 ± 15 HV, which was much higher than those reported in the literature. The microstructure of AlCrFeNiV was composed of two different types of body-centered cubic (BCC) structures, BCC1 (Al, Cr, Fe, and Ni) and BCC2 (enriched V and Cr). A mixture of different BCC systems produced solution strengthening, which was responsible for the superior hardness. Moreover, the reciprocating sliding wear behavior of HEA against Al2O3 balls under dry and lubricated conditions at ambient temperature was investigated. The wear rates of AlCrFeNiV against Al2O3 under dry wear and lubrication were 17.2 × 10−5 mm3 N−1·m−1 and 12.4 × 10−5 mm3N−1·m−1, respectively, which were of the same order of magnitude as the wear rates of BCC HEAs. Regardless of the dry wear or wear with lubrication, the wear mechanism of the HEA was abrasive and delamination wear.

Investigation of Fly ash Polymer Composite of Fly ash Polymer Composite

Abstract: Industrial waste like fly-ash which is creating environmental problems, is mainly used as a buildingmaterial due to its low cost and easy availability. But the main disadvantage of these bricks is its low strength. So, a lot of research is going on to increase the strength of these bricks. The presentresearch work is carried out to develop a new systematic procedure to produce fly ash composite bricks which will have higher compressive strength. Here the fly-ash is mixed with Cold setting resin at different proportions and water treated at different temperatures to find out a solution to the brick industry. The compressive strength, Hardness, water absorption, Density and thermal conductivity of the fly ash-resin powder bricks obtained under optimum test conditions are 11.24MPa, 47.37HV, 19.09% 1.68 g/cm3, and 0.055 W/mK respectively. The sliding wear behavior is also investigated. The structure-property correlation of these composites is studied using X-ray diffraction, FTIR analysis and scanning electron microscopy

An investigation on dry sliding wear behavior of aluminum based metal matrix composites using grey relational analysis coupled with principle component analysis

The current study reports on wear properties of aluminum 6061-T6 reinforced with titanium carbide and graphite hybrid metal matrix composite using principal component analysis based grey relational analysis. Experiments were carried out using Taguchi's L9 orthogonal array. The dry sliding wear properties of composite samples are evaluated using a Pin-on-Disc apparatus. The effects of wear parameter input variables such as load, sliding speed, and sliding distance on different output responses, namely wear rate, friction force, and coefficient of friction, were investigated in this work. Using grey relational analysis in conjunction with principal component analysis, three output responses from each experiment were normalized into a weighted grey relational grade. According to the analysis of variance, the most influential parameter is sliding velocity (45.51%), followed by load (26.75%) and sliding distance (2.94%), all of which contribute to the quality characteristics. Additional experiments have confirmed optimal results. Finally, a scanning electron microscopic analysis was performed to investigate the wear mechanism.

Optimization and analysis of dry sliding wear behaviour of N-B4C/MOS2 unreinforced AA2219 nano hybrid composites using response surface methodology

The effect of heat treatment on nano-size B4C particle reinforced hybrid composites is discussed in this paper. For this, hybrid reinforced AA2219 composites with 2% by weight nano B4C and 2% by weight MoS2 particulates were fabricated using a two-stage stir casting process, and the specimens were heat treated to assess their influence on wear behavior. Experiments were carried out to study the wear behavior by varying important factors such as aging temperature, load, and sliding distance. Response Surface Methodology (RSM) designed by Box-Behnken was used to identify the critical variables influencing wear rate and optimize wear behavior. To comprehend the wear mechanisms involved, an analysis of the worn surface was presented. Based on the analysis, a regression equation with a predictability of 97.2% was developed for the response to obtain the optimum wear rate. The following order effectively captures the relative importance of the various factors determining the alloy's wear resistance: sliding distance, load, and aging temperature. When compared to load and sliding distance, heat treatments via artificial aging in the temperature range of 200-240 °C have no significant effect on the wear resistance of hybrid AA2219 composites reinforced with n-B4C and MoS2 particulates. However, when a temperature range of 200-240 °C is considered, composites exhibit better wear resistance at the aging temperature of 240 °C with ice quenching.

Dry sliding wear behavior of Poly Ether Ether Ketone (PEEK) reinforced with graphite and synthetic diamond particles

Tribo film modification by synthetic diamond filler is an important study in developing polymer composite-based tribo components to avoid material loss during the sliding process. Anti-wear and anti-friction responsiveness were investigated by adding synthetic diamond particles (0–1 wt%) and graphite particles (0–1 wt%) to a Poly Ether Ether Ketone (PEEK) matrix under dry sliding conditions. Adding high-strength synthetic diamond filler offers more resistance to deformation of the PEEK composite, significantly improving its hardness and wear resistance properties. Altering synthetic diamond and graphite filler concentrations changes the wear process by modifying the tribo film characteristics, specifically at 0.5 % diamond and 0.75 % graphite particles, showing the lowest friction. The measured ID/IG ratio of transfer film was 0.92 by Raman spectra analysis, referring to the crystallized graphitic structure in the tribo film. XPS and Raman spectra analyses show that the tribo-chemical products of tribo film improve the lubricity and load-bearing ability of the composite. The mechanical effects of synthetic diamond particles and the tribochemical interactions between the sliding pair release polymer chelates strongly bind the tribo film to the counter surface. This increases the strength of the tribo film bond, which significantly improves tribo performance.

Tribological behaviour of PTFE composites: Interplay between reinforcement type and counterface material

In this paper, we studied the sliding wear behaviour of polytetrafluoroethylene (PTFE)-based composites under conditions relevant to rotary seals. We specifically aimed to investigate the interactions between different particle-based reinforcements (lamellar or spheroidal bronze particles, PEEK particles) and different counterfaces (uncoated or Cr2O3-coated stainless steel), building upon our own previous work on fibre reinforced-composites to make up for the paucity of literature papers on the role of counterfaces. Pin-on-disc tests were performed under different load and speed conditions using spherical-tipped composite pins against coated or uncoated stainless steel discs to mimic the (initially) non-conformal, unidirectional sliding contact of lip seals. Though all composites attained a steady-state regime controlled by a tribochemical wear mechanism, namely tribofilm formation, there were significant differences among the tribofilms produced by different tribo-systems. Systems that released fine, oxidized metal debris (bronze-filled PTFE and/or uncoated counterpart) developed >1 μm thick, continuous tribofilms on both mating surfaces. Thickness and continuity of the tribofilm decreased with a non-wearable Cr2O3-coated counterpart and/or PEEK as a filler. The tribofilm was conducive to lower steady-state friction, but not lower wear, against stainless steel, whereas all performances (friction coefficient, specific wear rate) were levelled out with a Cr2O3-coated counterface.

Sliding friction and wear behaviour of ion nitrided and TiN coated AISI 4140 steel

ABSTRACT This work studies the friction and the sliding wear behaviour of surface treated SAE 4140 steel. The performance of ion nitriding and PVD TiN coatings applied by means of industrial processes as single or duplex treatments was evaluated. Although the deposited TiN coatings (0.7 µm thick) resulted thinner than most of the typically employed for sliding situations, the present work shows that they can provide very good protection. The use of ion nitriding as a pretreatment proved to be beneficial when combined with such a thin coating. However, in the pin on disc sliding tests the coated discs developed the highest friction coefficients and boosted the damage in the steel pins.

Al-RHEA Particulates MMCs by PM Route: Mechanical Properties and Sliding Wear Response

New particle reinforced aluminum matrix composites with the addition of refractory High Entropy Alloy, MoTaNbVW, fabricated via powder metallurgy process were assessed for their properties. Basic mechanical properties (modulus of elasticity, hardness) for the aluminum matrix, the pure aluminum and the reinforcement phase were assessed by means of dynamic nano-indentation technique. Nano-indentation based creep response was also evaluated in these three areas of interest. Hardness shows an increase with the addition of the particulates and so does the elastic moduli and the ratio of the energy absorbed in the elastic region. The creep response was approached in terms of dislocation mobility and critical volume for their nucleation. The produced Al–HEA composites were also studied for their sliding wear behavior and showed that with the increase in percentage of RHEA particulates the wear resistance increases. Microstructural considerations, wear track morphologies, and debris characteristics were used for the assessment of the involved wear mechanisms.

Dry Sliding Friction and Wear Behavior of LM13/Zircon/Carbon (HMMC’s): An Experimental, Statistical and Artificial Neural Network Approach

Dry Sliding Friction and Wear Behavior of LM13/Zircon/Carbon (HMMC’s): An Experimental, Statistical and Artificial Neural Network Approach

Mechanical and sliding wear behavior of stir-squeeze cast and T6 heat-treated AA7068-ZrO2p composite

ABSTRACT The mechanical behavior of AA7068–4 wt.% ZrO2p composite was investigated at the cast and thermally treated (T6) conditions. The wear and friction behaviors were also examined under varying sliding distances (0–5000 m), paying special accentuation to the response parameters. The heat-treated 4% ZrO2p composite exhibited the highest ultimate tensile strength of 518 MPa, the least ductility of 7.48%, and the maximum hardness of 180 HV. The composite displayed improved wear resistance over the alloy irrespective of the condition. The friction coefficient and temperature rise due to frictional heating exhibited a revered trend. It was also observed that the induction of ZrO2p had effectually hindered the degree of subsurface deformation. The evolution and stability of mechanically mixed layer, oxide layer, cracking and deformed subsurface were detected as the operative wear mechanisms.

Evaluation of dry sliding wear behavior of abaca/glass fiber hybrid composite for tribological applications

Abaca is a high-strength natural fiber whose tribological behavior in epoxy polymer composite is unexplored to date. This paper aims to study the mechanical and dry sliding wear behavior of abaca fiber (A) and glass fiber (G) reinforced epoxy laminate composites with various stacking sequences. Symmetrically oriented laminate composites were fabricated in different stacking sequences (AAAA, AGAG, AGGA, and GAAG) using hand lay-up technique. Mechanical characterization is carried out as per ASTM standards. It is found that GAAG hybrid composite possesses maximum tensile strength (101.05 MPa). Meanwhile, AGAG composite shows maximum flexural strength (190.15 MPa) and interlaminar shear strength (5.97 MPa). Abrasive wear behavior of the composites is investigated by performing the test on a pin-on-disc tribo tester as per the ASTM G99 standard under dry sliding conditions. Tribological results indicate that hybridization of abaca and glass fiber into an epoxy matrix enhances the wear properties significantly. Maximum wear resistance is observed with AGGA-layered hybrid composite. The reduction in volumetric wear of AGGA composite is found to be lower than neat epoxy by 86.51%. However, the frictional force of AGGA composite increased by 54.17%. Furthermore, the morphology of fractured and worn-out surfaces is studied using a scanning electron microscope. It is inferred that failure is mainly due to the development of micro-cracks on both fiber and matrix, combined with fiber fragmentation, plowing, and debonding.