Wear Behavior Of Alloy Research Articles

Development of a Neural Network Model and Taguchi-Based Optimization for Dry Sliding Wear Performance of Al 6065 Alloy Reinforced with Nano SiC and Graphene Nanoplatelets

The Al6065 alloy is widely used in various applications, including tubing for furniture, railway and bus structures, pylons, platforms, and pipelines. However, due to the wear experienced in these applications, it is essential to enhance the wear confrontation of this alloy. To address this issue, this research focuses on reinforcing Al6065 with nanoparticles of silicon carbide and graphene by means of the stir casting method. The wear behaviour of the alloy is studied by varying the rotational speed, load, and composition of reinforcement in the stir casting machine using Taguchi design of experiment. The rate of wear and friction coefficient are measured as responses. The obtained results are then analysed and optimized for the minimum of the output responses using S/N ratio analysis. Further, ANOVA is carried out to determine the influence of each parameter, and a model of the neural network is developed to predict the response. The findings indicate that cumulative the percentage of reinforcement enhances the wear resistance of the alloy. The optimized values of the rotational speed, load, and composition of reinforcement lead to improved wear resistance, with a corresponding decrease in the coefficient of friction. The ANOVA results reveal that the rotational speed and load significantly affect the responses, while the reinforcement composition has a moderate effect. The developed neural network model accurately predicts the response with a high degree of accuracy. The model can be used to optimize the wear behaviour of Al6065 alloy reinforced with nanoparticles of silicon carbide and graphene, as well as for prediction of the alloy's wear behaviour in various application environments. In conclusion, this research delivers a complete thoughtful of the wear behaviour of Al6065 alloy reinforced with nanoparticles of silicon carbide and graphene. The findings can be used to optimize the wear resistance and improve the routine of this alloy in various applications.

Study on microstructure, mechanical and wear behavior of AA7075/hBN composites fabricated via liquid metallurgy

These research works investigate microstructure, mechanical strength and wear characteristics of AA7075/ hBN composites. AA7075/hBN composites are manufactured through two- step stir casting techniques with varying (0–7.5 wt%) hBN particles and subjected to T6 heat treatment. The optical microscopy of the composites shows that the reinforcement particles were distributed finely and with few cluster formations. The results stated that improved hardness on AA7075/5.0 wt% hBN composite as compared to as-cast alloy. The wear behaviour of alloy and composites are analysed on a pin-on-disc tribometer with varying applied loads of (20–60 N), a sliding velocity of 2.0 m/s, and a sliding distance of 3000 m, with EN31 steel as a counterpart. The wear rate and coefficient of friction of the composite reduced as the hBN particle concentration increased. A scanning electron microscope (SEM) is used to analyses the wear process on the worn surface, its reveals abrasion, oxide layer, and delamination as wear mechanisms under varying applied load conditions.

Influence of silver addition on wear characteristics of Cu-Al-Mn shape memory alloys

The aim of the present work is to study wear resistance and hardness of Cu-Al-Mn shape memory alloys prepared by the addition of Silver(Ag) as alloying element. Cu-Al-Mn-Ag shape memory alloys are prepared by varying the Ag concentration of 2%, 4% & 6% (wt.%). Wear behavior of alloys are investigated by using a Pin on disc tribometer at room temperature under dry sliding conditions by considering three parameters i.e. applied load, sliding speed and sliding distance. Hardness measurement is recorded by Rockwell hardness testing equipment. From the experimental findings it is observed that the amount of silver added in the alloys has shown significant effect in the improvement of wear resistance and hardness of prepared alloys. As the pin on disc speed increased, wear was reduced by 55%. A reduction in wear of 42% was observed with an increase in the volume fraction of silver.

Effects of heat treatment on the lubricated sliding wear behaviour of zinc-based alloy containing nickel under varying test conditions

Abstract This investigation presents the observations made pertaining to the lubricated sliding wear response of a zinc-based alloy containing nickel over a range of applied pressures and sliding speeds. Properties studied were wear rate and frictional heating. The varying wear response of the samples under different material and test conditions has been substantiated through the features of wear surfaces, subsurface regions, and debris. The role of various microconstituents in the material and their specific features have been correlated with the observed wear behaviour of the alloy in different material and test conditions. The wear rate and frictional heating increased with pressure and speed. The data plots in general comprised initially low slope followed by a higher slope at larger applied pressures. Heat-treated samples performed better than the as-cast one except at the maximum sliding speed; a reverse trend was noted in the latter case. The study suggests the benefits of heat treatment in terms of improved wear response of the alloy under specific test conditions. Moreover, the wear behaviour of the samples for different material and test conditions could be explained in terms of the features of their microconstituents and the predominance of one set of factors causing improved wear behaviour over the other producing a reverse effect.

SOME PROPERTIES OF BIOMEDICAL Ti6Al4V ALLOY IN DIFFERENT SOLUTIONS

The aim of the present investigation is to study the effect of different simulated solutions onwear behavior, chemical properties and ion release of Ti-6Al-4V alloy which used in humanbody. For this purpose three solutions have been used (Hank's solution, 0.9NaCl andartificial saliva). The corrosion properties of Ti-6Al-4V implant alloy were examined at37ºC by using electrochemical techniques, such as the potentiodynamic method and opencircuit potential (OCP). The electrochemical corrosion characteristics of Ti-6Al-4V implantalloys in three biological solutions were measured in terms of the corrosion potential (Ecorr)and the corrosion current density (icorr ).Wear behavior was investigated by using pin-ondisctribometers at human temperature under different loads (10,15,20)N. The wear testconsisted of measuring the weight loss of samples. The metal ion release of base andalloying element by immersed specimens into various solutions for 7 days (168 hours) at37ºC. The result found that the Ti6Al4V implant alloy in three biological solutions exhibiteda characteristic of a good behavior. The superior corrosion resistance these alloy whichcurrent density measured in (nA/cm2). The weight loss of samples by wear test increase withincrease load and time. After applied heat treatment, about 40% enhancement in the wearbehavior of alloy. The quantity of Al element metal release of implant alloy with variationfluids which increase with decrease the value of pH and little amount of vanadium elementin hank's solution.

Effect of Gd on microstructure, mechanical properties and wear behavior of as-cast Mg–5Sn alloy

Effect of minor Gd addition on the microstructure, mechanical properties and wear behavior of as-cast Mg–5Sn-based alloy was investigated by means of OM, XRD, SEM, EDS, a super depth-of-field 3D system, standard high-temperature tensile testing and dry sliding wear testing. Minor Gd addition has strong effect on changing the morphology of the Mg–5Sn binary alloy. Gd addition benefits the grain refinement of the primary α-Mg phase, as well as the formation and homogeneous distribution of the secondary Mg2Sn phase. The mechanical properties of the Mg–5Sn alloys at ambient and elevated temperatures are significantly enhanced by Gd addition. The wear behavior of the Mg–5Sn alloy is also improved with minor Gd addition. The alloy with 0.8% Gd addition exhibits the best ultimate tensile strength and elongation as well as the optimal wear behavior. Additionally, the worn surface of the Mg–5Sn–Gd becomes smoother in higher Gd-containing alloys. The best wear behavior of alloy was exhibited when Gd addition was up to 0.8%, showing a much smoother worn surface than that of control sample. The improvement of tensile properties is mainly attributed to the refinement of microstructure and the increasing amount and uniform distribution of Mg2Sn phase. The larger amount of Mg2Sn phase uniformly distributed at the grain boundary of Mg–Sn–Gd alloys act as a lubrication during sliding, and combined with smaller grain size improve wear behavior of the binary alloy.

Wear Behaviour of New CoCrMoTi Dental Alloys

A new composition of a dental cobalt alloy was proposed from the system CoCrMoTi, which are proposed for dental applications. Three content of titanium were used in commercial matrix of CoCrMo alloy in order to reveal the wear behavior of these alloys. The results showed that titanium alloying may improve wear behaviour by increasing the friction coefficient.

Experimental Study on the Effect of Microstructure on Dry Sliding Wear Behavior of Titanium Alloy Using Taguchi Experimental Design

The present article depicts the influence of independent control factors such as microstructural variation, normal load, sliding velocity, and test duration on the dry sliding wear behavior of titanium alloy at room temperature using a statistical approach. Different heat treatments were carried out in a controlled manner to produce various microstructural features (i.e., lamellar, bimodal, and equiaxed) in this alloy. A lamellar microstructure is found to be harder than bimodal microstructure followed by an equiaxed microstructure in this alloy. Dry sliding wear tests were carried out using a multiple tribotester following a well-planned experimental schedule based on Taguchi's orthogonal arrays. The dry sliding wear behavior of this alloy consisting of various microstructural features is related to their hardness values. The results indicated that a lamellar microstructure has the lowest sliding wear resistance followed by bimodal and equiaxed microstructures. Using signal-to-noise ratios and analysis of variance (ANOVA), an optimal combination of control factors that minimize the dry sliding wear in this alloy were determined. Among all four control factors, normal load is the most significant control factor influencing the dry sliding wear behavior of the investigated titanium alloy, followed by microstructural variation, sliding velocity, and test duration. Normal load has a greater static influence of 39.53%, microstructural variation has an influence of 31.55%, sliding velocity has an influence of 21.6%, and test duration has an influence of 5.7% on the dry sliding wear of this alloy. Two wear mechanisms were identified: oxidative wear occurs at the lowest sliding velocity and delamination wear occurs at the highest sliding velocity. Optical microscopy, scanning electron microscopy, and Rockwell hardness measurements were used to characterize the microstructures in order to correlate the results obtained.

Effect of iron on wear behavior of as-cast and heat-treated hypereutectic Al–18Si–4Cu–0.5Mg alloy: A Taguchi approach

This study describes the influence of Fe (wt%) on the microstructure, hardness, and wear behavior of Al–18Si–4Cu–0.5Mg– XFe ( X = Fe, at 0.4, 2.0, and 5.0 wt%) hypereutectic Al–Si alloy. The range of alloys was selected on the basis of literature study. The literature revealed that most of the studies on the effect of iron have been focused on either hypo-eutectic Al–Si alloys or lower levels of iron in the alloy. As Fe-rich intermetallic compounds are high melting point compounds, it is expected that they should improve the high temperature strength of the Al–Si alloys. The higher iron contents were specifically selected to obtain the advantage of high temperature stability leading to high wear resistance. Microstructure has been characterized using optical microscopy, scanning electron micrography, and image analysis studies. Maximum hardness of the alloy was obtained when solutionized (at 500 ℃) for 4 h followed by artificial aging (at 190 ℃) for 6 h. Heat-treated samples with only maximum hardness were further tested for wear behavior. The wear behavior of alloy in the as-cast and heat-treated conditions has been analyzed using Taguchi approach and analysis of variance analysis to find out the factors that affect wear significantly.

Effect of Cd on Microstructure and Dry Sliding Wear Behavior of (Al-12%Si) Alloy

The aim of the present research is to study the effect of cadmium addition on microstructure and wear behavior of the alloy (Al-12%Si) under dry sliding conditions. Wear behavior was studied by using the Pin-On- Disc technique under different conditions at applied loads 5-20 N, at constant sliding speed and in constant time. The steel disc hardness was 35HRc. All alloys were prepared with different percentages of cadmium (1.0, 2.0, 3.0) wt%. Also the base alloy was prepared by melting and pouring the molten metal in a metallic mold. It was found that the cadmium addition to Al-Si matrix decreases the wear rate and improves the wear properties for alloys containing -Cd under loads above 10N. It was also found that the alloy Al-12%Si containing 3%Cd is the best alloy in wear resistance and friction coefficient. This is due to presence of the Cd-phase as cuboids or hard particles distributed in a eutectic matrix which reduces the friction coefficient at high loads (20N).

Influence of T4 Heat Treatment on Tribological Behavior of Za27 Alloy Under Lubricated Sliding Condition

The effects of heat treatment on the microstructure, hardness, tensile properties, and tribological behavior of ZA27 alloy were examined. The alloys were prepared by conventional melting and casting route. The heat treatment of samples included the heating up to 370 °C for 3 or 5 h, quenching in water, and natural aging. Lubricated sliding wear test were conducted on as-cast and heat-treated ZA27 samples using block-on-disc machine. The friction and wear behavior of alloys were tested in contact with steel discs using combinations of three levels of load (10, 30, and 50 N) and three levels of linear sliding speeds (0.26, 0.50, and 1.00 m/s). To determine the wear mechanisms, the worn surfaces of the samples were examined by scanning electron microscopy (SEM). The heat treatment resulted in reduction in the hardness and tensile strength but increase in elongation. The heat-treated alloy samples attained improved tribological behavior over the as-cast ones, under all combinations of sliding speeds and contact loads. The rate of improvement increased with duration of solutionizing process before quenching in water. Obtained tribological results were related to the effects of heat treatment on microstructure changes of alloy.

Effect of material and test parameters on wear behaviour of eutectic Al–Si alloy (LM13)

This paper investigates the effects of contact pressure, sliding speed and alloy condition on dry sliding wear behaviour of LM13 (Al–12Si–0˙8Cu–1˙0Ni–0˙6Mg) alloy. A pin on disc type wear testing machine was used to study the wear behaviour of alloy in untreated, melt and heat treated condition. Dry sliding wear tests were performed at two contact pressures (0˙31 and 0˙93 MPa) and four sliding speeds (0˙2, 0˙5, 0˙9 and 2˙0 m s–1). The wear rate decreased with the increase in sliding speed irrespective of contact pressure and alloy condition used in this work. The untreated alloy exhibited higher wear rate than melt and heat treated alloy. The refinement of eutectic Si by melt treatment and spheroidisation of eutectic Si after heat treatment of LM13 alloy have been attributed to the reduction in wear. Melt treatment and heat treatment of LM13 alloy increased the hardness and tensile strength, while increase in ductility was marginal.

Structure, Mechanical Properties and Wear Resistance of High-vanadium Cast Iron

A series of melts with carbon content 1.38-4.16% and that of vanadium 5.25-15.50% was made. The X-ray diffraction of the examined alloys revealed the presence of three phases, i.e. ferrite, alloyed cementite, and VC x carbide. The relationships between the content of carbon and vanadium corresponding to eutectic structure (the eutectic line) as well as the degree of eutectic saturation S c were determined. Besides eutectics, the high-vanadium cast iron holds the following constituents in its matrix: alloyed ferrite, granular pearlite, and lamellar pearlite as well as a mixture of alloyed ferrite+granular pearlite, granular pearlite+ lamellar pearlite. The results show that passing from ferritic matrix through granular pearlitic and to lamellar pearlitic matrix, hardness HB, tensile strength R m , and yield strength H 0.2 , increases while plastic properties of alloys represented by elongation As decreases. The wear behaviour of alloys was tested in two different modes specimen-abrasive paper test (P1) and specimen-counterspecimen test (P2). The results obtained in test P1 are following: a) alloys with ferritic matrix and of the lowest hardness (182-189 HB) are characterised by the lowest abrasion wear resistance (s=3.14-3.93 mg/m), b) in alloys with a pearlitic matrix and hardness in the range of 387-416 HB the abrasion wear resistance is comparable to that of Hadfield cast steel (about s=2 mg/m) and c) cast iron with lamellar pearlite+granular pearlite matrix and hardness 322 to 401 HB gives the highest abrasion wear resistance of s=0.24-0.62 mg/m. In general, it can be stated that the abrasion wear in test P2 is higher than in test P1.

High-stress abrasive wear behaviour of Al-2014 alloy and its SiC composite

The dispersoid Metal Matrix Composites (MMCs) of the Al-Cu alloy have shown changes in their physical and mechanical properties over the base alloy and are seen as potential materials for use in different engineering components. The present paper compares the high-stress abrasive wear behaviour under different loads and ageing conditions (the cast and heat-treated conditions) of the alloy and the SiC dispersoid reinforced composite, prepared by adopting the liquid metallurgy route by stir casting. The wear rates were obtained and compared. It was found that the composite exhibited improved wear resistance (a lower wear rate) than the alloy in both the cast and aged conditions. The high-stress abrasive wear behaviour of the alloy and the composite in the cast and heat-treated conditions were carried out and the wear rate obtained was compared.

The effect of PVD coatings on the wear behaviour of magnesium alloys

In this study, AlN/TiN was coated on magnesium alloys using physical vapour deposition (PVD) technique of DC magnetron sputtering, and the influence of the coating on the wear behaviour of the alloys was examined. A physical vapour deposition system for coating processes, a reciprocating wear system for wear tests, a universal hardness equipment for hardness measurement, a X-ray diffractometer (XRD) for compositional analysis of the coating, and a scanning electron microscopy (SEM) for surface examinations were used. It was determined that the wear resistance of the magnesium alloys can be increased by PVD coatings. However, small structural defects which could arise from the coating process or substrate were observed in the coating layers.

Effects of heat treatment on the lubricated slading wear behaviour of zinc-based alloy containing nickel under varying test conditions

Abstract This investigation presents the observations made pertaining to the lubricated slading wear response of a zinc-based alloy containing nickel over a range of applied pressures and slading speeds. Properties studied were wear rate and fractional heating. The varying wear response of the samples under different material and test conditions has been substantiated through the features of wear surfaces, subsurface regions, and debris. The role of various microconstituents in the material and their specific features have been correlated with the observed wear behaviour of the alloy in different material and test conditions. The wear rate and fractional heating increased with pressure and speed. The data plots in general comprised initially low slope followed by a higher slope at larger applied pressures. Heat-treated samples performed better than the as-cast one except at the maximum sliding speed; a reverse trend was noted in the latter case. The studq suggests the benefits of heat treatment in terms o...

Slurry Wear Characteristics of a Zinc-Based Alloy

An attempt has been made in this investigation to assess the wear behavior of a zinc-based alloy in slurry. The influence of the sand content of the slurry and traversal speed and distance on the wear response of the alloy has been examined. Tests were also conducted in the liquid-only medium to assess the role played by the suspended sand particles in the medium. Testing the samples in the liquid-only medium (i.e., without sand particles) caused maximum wear rate. It was also observed that an intermediate sand concentration in the liquid exists wherein the samples experienced maximum wear rate (although less than in the liquid-only medium). Further, increasing the speed of rotation of the specimens in the liquid plus sand environments led to higher wear rate while the trend tended to reverse in the sand-free liquid environment. The alloy initially displayed increased wear rate with increasing traversal distance. This was followed by the attainment of the maximum, a decrease in the wear rate and then a steady state value at longer traversal distances. Wear behavior of the alloy under different experimental conditions was further substantiated through the features of the affected wear surfaces and subsurface regions (perpendicular below the affected surfaces).

The Effect of Heat Treatment on Sliding Wear Behaviour of a Zinc-Based Alloy Containing Nickel and Silicon

This investigation deals with the observations made pertaining to the sliding wear behaviour of a zinc-based alloy containing nickel and silicon in partially lubricated condition. Wear tests were conducted over a range of applied pressures and sliding speeds. The effect of microstructural changes brought about through T6 heat treatment involving solutionizing followed by artificial ageing on wear behaviour was also investigated. The wear rate increased with pressure. The slope of the wear rate versus pressure plots was low initially up to a specific pressure. This was followed by a higher slope beyond the (specific) pressure. In some cases, the rate of change in wear rate, i.e. the slope, decreased at still higher pressures. Moreover, the (specific) pressure decreased with sliding speed in general. Increasing sliding speed caused the wear rate of the as-cast zinc-based alloy to increase up to a sliding speed of 2.68 m/s. The trend reversed at a still higher speed of 4.60 m/s. However, increasing wear rate with speed was noted for the heat-treated alloy over the entire speed range. Heat treatment led to reduced wear rate up to a sliding speed of 2.68 m/s. An opposite trend was observed at a higher speed of 4.60 m/s in this case. Specimen seizure was noted at speeds above 2.68 m/s in the case of the as-cast alloy whereas seizure took place only at 4.60 m/s for the heat-treated alloy samples. Frictional heating increased with pressure and speed. The specific response and changing mode of distribution of various phases were thought to be responsible for the typical wear behaviour of the alloy in specific material and test conditions. The predominance of parameters like thermal stability and cracking tendency over each other is suggested to lead to the varying wear behaviour of the alloy in different (material and sliding) conditions. The wear response of the samples has been substantiated through characteristics of their wear surfaces, subsurface regions and debris.

Interplay between oxidation and wear behavior of the Ti-48Al-2Cr-2Nb-1B alloy

This study deals with some aspects of the dry sliding behavior of a gamma TiAl-based alloy with the following composition: Ti-48Al-2Cr-2Nb-1B (at. pct). The tribological system consisted of an AISI M2 steel disk sliding against TiAl alloy sheets. Different alloy microstructures—duplex, equiaxed, and lamellar—were considered, in order to check for their possible effect on the wear behavior. At low loads, a mainly abrasive mechanism was inferred from the phases present in the debris collected at the end of each test. An additional contribution from oxidational phenomena was found at higher loads. In such conditions, the equiaxed samples displayed a slightly better wear resistance. A remarkable improvement in wear resistance was observed when the alloy specimens were tested without a preliminary removal of the surface layer which resulted from the heat treatments carried out to obtain different microstructures. Again, some differences were found in the wear behavior of alloys with different microstructures. In this case, though, the difference can rather be attributed to the different morphology of the surface layers. Better performances were observed in those samples, both duplex and equiaxed, in which a good mechanical matching between the alloy and the outer scale was accomplished, thanks to the presence of a hardened interdiffusion zone. An aspect which should be considered further is the tribological coupling of the as-treated alloys. Indeed, the elevated hardness and surface roughness of the coating yields a significant wear of the sliding counterface.

Sliding wear behavior of some Al-Si alloys: Role of shape and size of Si particles and test conditions

In this investigation, effects of the shape and size of silicon particles have been studied on the sliding wear response of two Al-Si alloys, namely, LM13 and LM29. The LM13 alloy comprised 11.70 pct Si, 1.02 pct Cu, 1.50 pct Ni, 1.08 pct Mg, 0.70 pct Fe, 0.80 pct Mn, and remainder Al. The LM29 alloy contained 23.25 pct Si, 0.80 pct Cu, 1.10 pct Ni, 1.21 pct Mg, 0.71 pct Fe, 0.61 pct Mn, and remainder Al. Wear tests were conducted under the conditions of varying sliding speed and applied pressure. The alloys were also characterized for their microstructural features and mechanical properties. The presence of primary silicon particles in the alloy led to a higher hardness but lower tensile properties. Further, refinement in the size of the primary particles improved the mechanical properties of the alloy system. The wear behavior of the alloys was influenced by the presence of primary Si particles and was a function of their size. Samples with refined but identical microconstituents (e.g., pressure cast vs gravity cast LM29 in terms of the size of primary Si particles and dendritic arm spacing) exhibited better wear characteristics. Their overall effect was further controlled by the test conditions. It was observed that test conditions leading to the generation of an optimal degree of frictional heating offer the best wear resistance. This was attributed to the reduced microcracking tendency of the alloy system otherwise introduced by the Si particles. The reduced microcracking tendency in turn allows the Si phase to carry load more effectively and impart better thermal stability to the alloy system. This caused improved wear resistance under the circumstances. Further, the primary Si particles improved the wear resistance of the alloy system (e.g., gravity-cast LM29 vs gravity-cast LM13) under high operating temperature conditions. Additional thermal stability and protection offered to the matrix by the primary Si phase, under the conditions of reduced microcracking tendency, were the reasons for the improved wear characteristics of the alloy system. Conversely, a reverse effect was produced at low operating temperatures in view of the predominating microcracking tendency. The study suggests that shape, size, microcracking tendency, and thermal stability of different microconstituents greatly control the mechanical and tribological properties of these alloys. The extent of effective load transfer between the phases plays an important role in this regard. Further, the overall effect of these factors is significantly governed by the test conditions.