Wear Resistance Of Aluminium Alloy Research Articles

Sliding Wear Behaviour of Nickel-Coated Short Fibre-Reinforced Al7075 Composites

In the present study, Aluminium-7075 alloy is reinforced with nickel-coated short carbon fibres in the form of short fibre. These composites were prepared by stir casting method with 2, 4, 6 and 8 wt.% of nickel-coated carbon fibres. Wear resistance of aluminium alloy and its composites were analysed according to the ASTM standards. The experiments were conducted using pin-on-disc wear test and rig wear test method with different loads. From the wear test, it was found that aluminium composites with 8% nickel-coated carbon fibre rate of wear are minimum. Worn and fractured surfaces of cast aluminium alloy and the developed composites are analysed by SEM. The test results reveal that the wear resistance of the prepared MMCs improves with the addition of carbon fibre.

Artificial neural network approach for the prediction of wear for Al6061 with reinforcements

In the prospect of finding a lightweight and wear-resistant materials, researchers have considered aluminium-based metal matrix composites (MMC), as aluminium has a wide variety of applications but possesses low wear resistance properties. To enhance the wear resistance of aluminium alloys, ceramic particles are reinforced. In this endeavour, commercially available aluminium alloy is reinforced with 2, 4 and 6 wt% of silicon carbide (SiC) and Vanadium pentoxide (V2O5) powder to improve its wear resistance. The intensity of reinforcement in the matrix was uniform, and the Scanning Electron Microscope image showed the grain refinement and grain boundary of the MMC’s. Wear tests were performed for L16 array set, uncertainty analysis of wear measurement is evaluated, and data were used to develop Artificial Neural Network (ANN) model. The efficient ANN model with a regression coefficient of 0.999 was used to make predictions for remaining sets. Experimental and predicted wear results were analysed; it is observed that higher wt% reinforcement of V2O5 increased wear resistance of aluminium compared to SiC. The methodology adapted using ANN for prediction of wear using meagre experimentation, will lay a path for tribologists to predict the wear of novel metal matrix composites in their endeavour of finding wear-resistant materials.

Dry sliding wear behavior of ultrasonic stir cast boron carbide reinforced aluminium nanocomposites

In the present work ultrasonic stir casting method is used to fabricate aluminium metal matrix nanocomposites reinforced with nano boron carbide (nB4C) particles with varying (0.5, 1, 1.5 and 2) weight percentages. Microhardness and nanoindentaion hardness of the nanocomposite is found to increase with increasing reinforcement content. Pin on disk apparatus is used to study the room temperature dry sliding wear behavior of fabricated composites and base alloy. Nominal contact pressures of 0.354–1.412 MPa and sliding speeds of 0.16–0.66 m s−1 are employed. Each test run is conducted for the fixed contact period of 15 min. Field emission scanning electron microscopy (FESEM) equipped with energy dispersive spectroscopy (EDS) is used to observe worn surface and wear debris to understand the undergoing wear mechanisms. It is observed that base alloy underwent mild to severe plastic deformation led oxidative delamination wear. Nanocomposites are subjected to combination of oxidative, abrasive and mild delamination wear. Nanocomposites display less mass loss and wear rate as compared to base alloy due to the protective tribolayer formed in the contact interface. Part of the mechanically mixed transfer layer is found to adhere firmly to the composite surface under higher load-speed condition. Extremely hard nB4C particle reinforcement is found beneficial for improving the wear resistance of aluminium alloy at varying combinations of load and speed.

Wear resistance of aluminum alloy modified with SiC by laser surface treatment

The work is devoted to establishing the effect of laser modification by SiC particles of the surface layers of 7075 aluminum alloy, on its wear resistance in friction conditions with a rigidly fixed and non-fixed abrasive. It has been revealed that with increasing linear energy of the laser beam, the thickness of the modified layer increases and the volume content of SiC particles in it increases. X-ray spectral and X-ray phase analysis of the layers modified with SiC particles confirmed the presence of silicon carbide particles and aluminum carbides in them. The speed of movement of the laser beam (linear energy of the beam) over the surface affects the structure and wear resistance of laser-modified layers as well as the heating of the substrate. In particular, with an increase in heat input from 740 to 1100 J/cm, the concentration of SiC particles increases by 25% in the modified layer, and the wear resistance during friction tests with a rigidly fixed abrasive by 1,7...2 times. It has been found that the wear resistance of the modified layer is almost not affected by the direction of friction (along or across the laser processing tracks), however, the ratio of adjacent tracks overlap significantly affects. Thus, the wear resistance of the modified layer under friction by a rigidly fixed abrasive increases with an increase in the size of SiC particles and their volume content, an increase in the linear energy of the laser beam and the tracks overlap ratio. When testing with a non-fixed abrasive, the trends in wear resistance remained, however, the influence of the factors analyzed above is much weaker

Effect of Nickel Reinforcement on Micro Hardness and Wear Resistance of Aluminium Alloy Al7075

Presently, wear resistance of aluminium alloys have gained a greater importance in various industrial applications. Research works regarding strengthening of aluminium alloys introduced a new class of composites, i.e. aluminium intermetallic composites. Aluminium alloy Al7075 with zinc as the major alloying element is widely used in various industrial fields, and there is a research scope in fabricating Al7075-Al3Ni intermetallic composites by reinforcing nickel particles. In this study, four composites of different weight percentages (i.e. 1%, 5%, 10%, and 15%) of nickel and base alloy were fabricated by using stir casting method. After fabrication, the materials were subjected to T6 heat treatment. The micro hardness evaluation of the composites before and after the heat treatment was performed, and compared with the base alloy. Micro hardness of base alloy was improved up to 146% by reinforcing 15% nickel followed by the heat treatment. Wear rate of heat treated base alloy and composites was studied. Heat treated Al7075+15% nickel composite shows more wear resistance (about 93% resistant than heat treated base alloy). The wear properties of heat treated Al7075+15% nickel composite was studied at different applied loads and sliding velocities.

Design of experiments to optimize casting process of aluminum alloy 7075 in addition of TiO2 using Taguchi method

Design of Experiments is the design of any task that aims to describe the variation of data under conditions that are hypothesized to reflect the variation. In this research, we analyzed various significant process parameters of the casting of aluminium alloy 7075 with TiO2 addition. An experiment was made to obtain an optimal setting for casting parameters to yield the optimum casting of aluminium alloy 7075. The process parameters are considered as melting temperature, filling time of the mould and the solidification time. The effect of selected parameters of casting towards the optimum cast of aluminium alloy 7075 will be accomplished using the Taguchi method. The purpose of adding titanium dioxide is to further enhance the physical properties like the hardness and its wear resistance of aluminium alloy 7075. The Taguchi method is used here to bring out the best settings possible for casting that depends on the above parameters. Minitab software is used to apply the Taguchi method.

An investigative study of dry sliding wear behaviour of cold deformed and as cast: Al5083

Aluminum alloy is well-known as a soft material with a low melting point, good castability and forgability property, and less wear resistance. It is also having magnificent mechanical properties and corrosion resistance. It can retain its strength even after welding. Further many a researcher has been working to improve the wear resistance of aluminum alloy by using composite but the major drawback is to mixing the reinforcement particle into the base material and also the erosion of reinforcement particle during its wear testing. Forging is a process which improves the strength of material causing the increase in hardness. In this research, researcher had investigated the dry sliding wear behavior of Al5083 by Pin-on-disc wear test machine under different load (30 N, 40 N and 50 N) and sliding speed (1.67 ms−1, 1.25 ms−1, 0.84 ms−1) at constant sliding time of 45 min. The pins were prepared from the forged material of Al5083 of dia. 6 mm and has a length of 40 mm each. All experiments were performed at room temperature, the mechanism of deformation triggered in the sliding surface of pin was analyzed with the aid of SEM.

Wear resistance of graphene nano-platelets (GNPs) reinforced AlSi10Mg matrix composite prepared by SLM

In order to improve the wear resistance of aluminum alloys and expand its applications, the microstructure and tribological properties of nano-graphene reinforced aluminum matrix composites—which were fabricated by selective laser melting (SLM)—were investigated. Experiments were conducted to investigate the effect of slide speeds (0.3–0.9 m/s) and normal loads (10N–30N), which demonstrated the dislocation strengthening and load strengthening resulting from the homogeneous dispersion of graphene nano-platelets (GNPs) enhance the wear resistance of GNPs/AlSi10Mg composites. With the increase of slide speed, the wear rate of composites decreases and the wear regime changes from abrasive wear to delamination wear, which is because the formation of a relatively stable mechanically mixed layer (MML) reduces the contact area between the counterbody material and the wear surface, and the nano-graphene bridges between the subsurface cracks improve the tribological performance. Meanwhile, with the increase of normal load, the predominant wear regime of the reinforced composite is the combination of delamination wear and oxidize wear. And the coefficient of friction (COF) decreases as the slide speed increases, which is because the self-lubricating property of graphene nano-platelets makes it easy to form interlayer sliding and reduce friction effectively.

Effect of surface self-nanocrystallization on friction and wear behavior of Al7075-T6511 alloy

Shot peening (SP) is an effective surface reinforced treatment, which can improve the surface properties of materials. Because of the poor wear resistance of aluminum alloys, the improvement of wear resistance has received more attention. In this research, Al7075-T6511 alloy was treated by the SP with different shot peening intensities to achieve the surface self-nanocrystallization and improve the dry friction and wear property. The surface microstructure of specimen before and after the SP was observed by using the optical microscope (OM), transmission electron microscopy (TEM) and x-ray diffraction (XRD). The surface roughness was examined by using laser confocal scanning microscope (CLSM). It has been found that the surface microhardness of the specimen was improved greatly after the SP. A nanocrystalline surface was generated, and the thickness of the severe plastic deformation layer increased with increase of the SP intensity. The results also show that the friction and wear mechanism of the SP-free specimen was severe adhesive wear and oxidation wear. While, the friction and wear mechanism of the SP-treated specimen was adhesive wear, accompanied with abrasive wear and oxidation wear.

Research of Surface Wear Resistance of Aluminum Alloy Modified with Minerals using Sclerometry Method

Improving the wear resistance of the surface of metal parts used in various industries is one of the relevant areas of materials science. The aim of this work was a comparative study of the wear resistance of a sample of an aluminum alloy (EN AW-2024, an aluminum alloy of the Al-Cu-Mg system) modified with ultrafine particles of minerals using the sclerometry method, which makes it possible to measure the physicomechanical properties of the material at the microscale, as well as determining some tribological parameters (hardness and elastic modulus) of a duralumin sample with a mineral coating.Wear resistance was measured using a NanoScan-4D scanning hardness tester using the multi-cycle friction method using a sapphire sphere with control of the pressing force and the deepening of the tip into the sample. The use of such a measurement system is especially important when testing thin modified layers, when the layer thickness is comparable with the surface roughness parameters and the influence of the substrate is excluded.The measurement results showed that the wear resistance of the surface of an aluminum alloy sample modified with ultrafine mineral particles increased by more than 12 times compared to the wear resistance of an aluminum alloy surface without modification. Also, measurements of the hardness and elastic modulus of the surface of the modified sample were performed taking into account the features of measuring the mechanical parameters of thin layers.The obtained parameters of the modified surface of the aluminum alloy can be further used to build models of the processes of friction and wear of the surface modified by ultrafine particles of minerals. The lack of an acceptable explanation of the nature of the special properties of the surface modified by particles of minerals of natural origin does not exclude the use of the observed effects to significantly increase the resource of various parts and mechanisms.

Microstructure and wear performance of arc-sprayed Al/316L stainless-steel composite coating

To improve the wear resistance of aluminium alloys, an Al/316L stainless-steel composite coating was successfully prepared on an aluminium alloy surface by two-channel-synchronization wire feeding arc spraying technology. The composite coating has a ductile (Al) and hard (stainless-steel) interpenetration structure. The interface between the substrate and the coating was fuzzy owing to the pinning interface of interpenetrating structure and the obvious diffusion layer near the interface, compared with 316L stainless-steel coating. The tribological properties of composite coatings were analysed. The wear resistance of the Al/316L stainless-steel composite coating was shown to be three times higher than that of the stainless-steel coating. The Al/316L stainless-steel composite coatings improved the wear resistance of aluminium alloy by a factor greater than nine. In the composite coating, the addition of Al splats promoted the formation of Fe3O4 and the interpenetrating structures, improving the wear resistance and crack propagation resistance of the coating.

Effect of oxidation time on the impact wear of micro-arc oxidation coating on aluminum alloy

Micro-arc oxidation (MAO) coating with different oxidation times was prepared on aluminum alloy to improve the impact wear resistance of aluminum alloy. Surface morphology and impact wear behavior of the coating with different oxidation times were investigated. Results showed that the MAO coating formed on aluminum alloy had a porous and island structure comprising α-Al2O3 and γ-Al2O3. Coating thickness increased with increasing oxidation time. The coating also had a lower impact force and higher energy absorption ratio than the substrate but had a lower wear volume, which decreased with increasing oxidation time. These results indicated that MAO coating can improve the impact wear resistance of aluminum alloy. Further study revealed that the wear mechanism of aluminum alloy was oxidation wear and contact fatigue spalling, whereas that of MAO coating was contact fatigue wear.

Assessment of Wear Resistance of Aluminium Alloy in Manufacturing Industry-A Review

Aluminium alloy composites are attaining vast industrialized recognition in the area of aircraft, automobile, aerospace as a result of its improved mechanical characteristics in relating to stiffness; quality and impact load to weight proportion and better wear protection. They are widely used in automobile industry to manufacture various parts where wear resistance is serious like valve, water coolant, cylinder lining, fan blade, piston and rings etc. Stir casting technique is a liquid state method for the fabrication of composite materials. The part critical to these functional areas is the valves which are often fabricated by stir casting method. The wear parameters considered in the study of wear resistance include sliding speeds and applied loads.

Structure and wear resistance of aluminium alloys coated with surface layer laser-modified by silicon carbide

Structure and wear resistance of aluminium alloys coated with surface layer laser-modified by silicon carbide

Influences of sealing solutions on anodized layer properties of 7075 aluminium alloy

Aluminium alloy has been widely used in the engineering applications due to high strength and light weight. The wear resistance of aluminium alloy was improved by anodizing process. The anodized film of aluminum alloy was composed of an inner thin compact layer (the barrier layer) and an outer thick porous layer. Sealing process was employed improve the hardness, corrosion, and wear resistance of anodized aluminium film. In this study, the sealing process was done by using sodium dichromate (Na2Cr2O7) potassium dichromate (K2Cr2O7) solution, and boiling water, respectively. The anodized layer was investigated by an optical microscope (OM) and scanning electron microscopy (SEM). The result showed that boiling water sealed films provided the highest anodized thickness layers compared with sodium dichromate and potassium dichromate. In addition, based on the tribology tests of anodized layers, boiling water sealing has the lower friction coefficient.

Improving interfacial, mechanical and tribological properties of alumina coatings on Al alloy by plasma arc heat-treatment of substrate

Plasma sprayed ceramic coatings can be used to improve the mechanical properties and wear resistance of aluminum alloys, but there are still some challenges to effectively increase their interfacial adhesion. Thus we conducted plasma arc-heat treatment (PA-HT) of Al alloy substrate before plasma spraying, hoping to tune the microstructure of Al2O3 coatings and improve their interfacial strength as well as mechanical and tribological properties. The influences of PA-HT on the microstructure of alumina coatings were analyzed by X-ray diffraction, transmission electron microscopy and scanning electron microscopy, while its effect on mechanical and tribological properties were evaluated by a nano-indentation tester and a friction and wear tester. Results demonstrate that a few columnar δ-Al2O3 generated on substrate surface after PA-HT at 200–250°C can induce the epitaxial growth of γ-Al2O3 grains in Al2O3 coatings, thereby enhancing their interfacial bonding. Besides, elevating substrate temperature can help alumina droplets to melt into the interior of substrate and eliminate holes at the interface, finally increasing the interfacial anchorage force. More importantly, no interfacial holes can allow the heat of droplets to be rapidly transmitted to substrate, which is beneficial to yield smaller crystals in coatings and greatly enhance their strength, hardness and wear resistance.

Preparation and performance of sol–gel-derived alumina film modified by stearic acid

Increasing wear resistance of aluminum alloys is of great importance for their practical application. In this paper, we have studied the tribological performance of the assembly of stearic acid on aluminum coated by sol–gel-derived alumina film. The samples were characterized by means of X-ray diffraction, infrared spectroscopy, contact angle measurements and a macro-friction and wear tester. The results show that the combination of stearic acid modification and sol–gel-derived alumina film can create superhydrophobic surfaces with a water contact angle of 155° and a sliding angle of 25°. As-obtained superhydrophobic surface can effectively reduced friction and largely increased antiwear life of aluminum, due to the combined beneficial effects of antiwear performance of sol–gel-derived alumina film and nanolubrication of self-assembled stearic acid overcoat.

Dry sliding wear characterization of Al 6061/rock dust composite

The influence of rock dust size (10–30 µm) and mass fraction (5%–15%) on density, hardness and dry sliding wear behavior of Al 6061/rock dust composite processed through stir casting was investigated. Wear behavior of the developed composite was characterized at different loads, sliding velocities and distances using pin-on-disc setup. The experiments were conducted based on Taguchi's L27 orthogonal array and the influence of process parameters on wear rate was studied using ANOVA. The experimental results reveal that the applied load and reinforcement size are the major parameters influencing the specific wear rate for all samples, followed by mass fraction of reinforcement, sliding velocity and sliding distance at the level of 47.61%, 28.57%, 19.04%, 9.52% and 4.76%, respectively. The developed regression equation was tested for its accuracy and made evident that it can be used for predicting the wear rate with minimal error. With the help of SEM images, the worn surfaces of the novel composite were studied and the analysis proves that the wear resistance of aluminium alloys can be well improved with the addition of rock dust as reinforcement.

Deep Cryogenic Treatment and CrN Coating Effects on Micro-Scale Abrasion of Aluminum Alloy AA 6101-T4

The endurance of components made of aluminum and aluminum alloys is often limited by their low yield strength and by their low wear resistance. The aim of this paper is to investigate the effect of different methods that can improve wear resistance of aluminum alloys. As a first approach, a highly wear resistant chromium nitrite layer was deposited by plasma vapor deposition on the surface of the aluminum alloy AA 6101-T4. In the second method, an ultra-deep cryogenic treatment was selected. Both methods have been previously used to improve the wear resistance of other harder substrate materials, like tool steel. To investigate the impact of the two methods on the wear resistance of such alloy, micro abrasive wear tests were carried out and an analysis based on the Archard’s law was considered. The results showed a decrease of the wear rate by 29% and 26% for the coated and for the cryogenically treated specimens, respectively, when compared to the as received material. The work also investigated the performance of three different methods (Allsopp, Double Intercept and Polynomial AT) usually considered to calculate the wear rate of coated samples. The three methods presented similar measures of wear rate for the substrate and for the coating

Tribological Behaviour of Aluminium Hybrid Metal Matrix Composite

Aluminum based metal matrix composites (MMCs) are appropriate materials for structural applications in the aircraft and automotive industries because they are ductile, highly conductive, lightweight and have a high strength to weight ratio. Wear and Friction behaviour of Al6061 with various percentage volumes of Multiwall carbon nanotube and Silicon Carbide reinforcement through stir casting method followed by die-casting was investigated. Wear test was made by using Pin on Disc Apparatus on the prepared Specimen. It was found that, under mild wear conditions, the composite displayed lower wear rate and friction coefficient compared to Aluminium. However, for severe wear conditions, the composite displayed higher wear rate and friction coefficient and it was clarified that the friction and wear behaviour of Al–SiC-MWCNT composite is largely influenced by the applied load and there exists a critical load beyond which CNTs could have a negative impact on the wear resistance of aluminium alloy. Also the hardness of the composite was increased by increasing the percent volume of reinforcement.