scholarly journals Mathematical Modeling and Analysis of Tribological Properties of AA6063 Aluminum Alloy Reinforced with Fly Ash by Using Response Surface Methodology

Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 403 ◽  
Author(s):  
Alaa Mohammed Razzaq ◽  
Dayang Laila Majid ◽  
Mohamad Ridzwan Ishak ◽  
Uday Muwafaq Basheer

Lightweight, high-strength metal matrix composites have attracted considerable interest because of their attractive physical, mechanical and tribological properties. Moreover, they may offer distinct advantages due to good strength and wear resistance. In this research, AA6063 was reinforced with FA particles using compocasting methods. The effects of fly ash content, load, sliding speed and performance tribology of AA6063 –FA composite were evaluated. Dry sliding wear tests were carried out according to experimental design using the pin-on-disc method with three different loads (24.5, 49 and 73.5 N) and three speeds (150, 200 and 250 rpm) at room temperature. Response surface methodology (RSM) was used to analyze the influence of the process parameters on the tribological behavior of the composites. The surface plot showed that the wear rate increased with increasing load, time and sliding velocity. In contrast, the friction coefficient decreased with increasing these parameters. Optimal models for wear rate and friction coefficient showed appropriate results that can be estimated, hence reducing wear testing time and cost.

2021 ◽  
Vol 55 (6) ◽  
Author(s):  
Aswathi A. Narayanan ◽  
R. S. Sudheesh

Hybrid PTFE/epoxy composites are widely used as materials for self-lubricating spherical bearing which are used in a high-temperature environment. In the present work, zirconium diboride (ZrB2) particles are incorporated to enhance high-temperature tribological properties of PTFE/epoxy composites. Pin on disc experiment is conducted with the aid of design of experiments (DOE) using central composite-response surface methodology (RSM). Under a load of 40 N and 1.25 m/s sliding speed, the optimum content 5.95 vol% of PTFE and 5.05 vol% of ZrB2, yields an ultralow coefficient of friction (COF) in conjunction with a low wear rate of the composite. The addition of ultra-high-temperature ceramic ZrB2 particles and solid lubricant PTFE is found to enhance the thermal conductivity and improve the heat transfer thereby reducing contact temperature. The use of optimum composition of the composite is capable of reducing the wear rate and high local temperature due to friction, implying its potential use as a self-lubricating spherical bearing liner material.


2021 ◽  
Vol 9 ◽  
Author(s):  
R. Kousik Kumaar ◽  
◽  
K. Somasundara Vinoth ◽  
Kavitha M ◽  
◽  
...  

This article aims in exploring the dry sliding wear performances on the aluminum (AA7075) metal matrix composites reinforced with molybdenum disulphide which is a solid lubricant using response surface methodology (RSM). Specific Wear Rate (SWR) for the AA7075 pure alloy, AA7075+2wt% molybdenum disulphide and AA7075+4wt% molybdenum disulphide were measured according to ASTM G99 standards in pin-on-disc apparatus. Design of experiments was selected with changed parameters like the varying percentage of molybdenum disulphide (%), applied load (N), and sliding velocity (m/s) based on Central Composite Design in response surface methodology considering them as continuous factors. Experiments for the specific wear rate of pure alloy and the composites were conducted. The volume loss was measured using the pin-on-disc apparatus from which the specific wear rate value was calculated. The obtained results are analyzed and a mathematical model was formulated using the response surface methodology. The optimum level parameters for the specific wear rate has been identified and the results of the experiment specify that the sliding velocity and molybdenum disulphide percentage have a substantial role in controlling the wear behaviour of composites when compared with the other parameter. The optimum condition for the specific wear rate was identified and experimented with for studying the result.


2021 ◽  
Author(s):  
Ravi Kumar Mandava ◽  
Vajram Venkata Reddy ◽  
Veeravalli Rama Koteswara Rao

Abstract In the present research work an effort has been made to study the wear and frictional behavior of Aluminium Metal Matrix composite (Al 7075 as a base alloy and fly ash (FA) and silicon carbide (SiC) as reinforcements) by using the stir casting method. To carry out this work, the wt. % of reinforcements FA (2.5%, 5%, 7.5% and 10%) and SiC (2.5%, 5%, 7.5% and 10%)have been used 5%, 10%, 15% and 20%. Initially, the mechanical studies have been conducted and the best mechanical properties obtained at 20 wt. % of FA and SiC. Later on, the composite was fabricated by 20 wt. % of FA, SiC reinforcements are used to check the wear and frictional behavior on a pin-on-disc machine at the dry condition. The dry sliding wear behavior was carried out at various input parameters such as applied force (10N, 20N, and 30N), sliding velocity (1.5m/s, 3m/s, and 4.5m/s), and sliding distance (1000 m, 2000 m, and 3000 m). Further, a scanning electron microscope (SEM) are used to observe the mixing of reinforcements and examine the worn surfaces. A response surface methodology (RSM) is the reasonable and accurate method for conducting the experiments and identifying the optimal wear parameters. Moreover, the RSM was helped to identify the most significant factor, which was the influence on the wear rate. Finally, it is decided that the applying force is the utmost significant factor that leaves an effect on wear rate. The sliding velocity and distance are acting as the lesser influence on the performance indicator.


Author(s):  
Vishnu Anil Kumar ◽  
Vaishnave Vinodkumar Vinod Kumar ◽  
Goutham S Menon ◽  
Sivcharan Bimaldev ◽  
Manu Sankar ◽  
...  

The current study deals with the development of a hybrid metal matrix composite and studies their wear characteristics. Suitable wt - % of Al2O3/B4C was reinforced into Al-Si-Mg alloy and the composites were fabricated using liquid metallurgy route. The developed composites were analyzed for their wear behavior by using a wear testing apparatus. Three process parameters including applied load, sliding distance, and velocity were chosen for carrying out the wear experiments. The influence of the reinforcement on wear rate was investigated through response surface methodology methods. The formulation of the regression equation was done and the effect of each experimental parameter was studied. Results from the investigation illustrate that the wear rate was found to decrease and then increase with the increasing wt-% of reinforcement and the wear rate was found to increase with an increase in the sliding distance but the wear rate was found to decrease with an increase in the sliding velocity. The worn-out surface of the hybrid composite was characterized using SEM.


Author(s):  
Ying Yan ◽  
Xuelin Lei ◽  
Yun He

The effect of nanoscale surface texture on the frictional and wear performances of nanocrystalline diamond films under water-lubricating conditions were comparatively investigated using a reciprocating ball-on-flat tribometer. Although the untreated nanocrystalline diamond film shows a stable frictional state with an average friction coefficient of 0.26, the subsequent textured films show a beneficial effect on rapidly reducing the friction coefficient, which decreased to a stable value of 0.1. Furthermore, compared with the nanocrystalline diamond coating, the textured films showed a large decreasing rate of the corresponding ball wear rate from 4.16 × 10−3 to 1.15 × 10−3 mm3/N/m. This is due to the fact that the hydrodynamic fluid film composed of water and debris can provide a good lubrication environment, so the entire friction process has reached the state of fluid lubrication. Meanwhile, the surface texture can greatly improve the hydrophilicity of the diamond films, and as the texture density increases, the water contact angle decreases from 94.75° of the nanocrystalline diamond film to 78.5° of the textured films. The proper textured diamond film (NCD90) exhibits superior tribological properties among all tested diamond films, such as short run-in period, low coefficient of friction, and wear rate.


2010 ◽  
Vol 654-656 ◽  
pp. 2763-2766 ◽  
Author(s):  
Li Wen Mu ◽  
Xin Feng ◽  
Yi Jun Shi ◽  
Huai Yuan Wang ◽  
Xiao Hua Lu

The tribological properties of polyimide (PI) composites reinforced with graphite or MoS2 sliding in liquid alkali and water as well as dry friction were investigated using a ring-on-ring tester. The results show that the friction coefficient (μ) and wear rate (W) for both graphite/PI and MoS2/PI composites in different liquid mediums are μdry>μwater >μalkali and Wwater>Wdry >Walkali. Results also indicate that the friction coefficient and wear rate of the PI composites filled with different solid lubricants are μMoS2 >μgraphite and W MoS2 >Wgraphite in different liquid mediums. In addition, the hydrophobic inorganic fillers are fit for the reinforcement of polymer-based composites sliding in liquid mediums. It is also concluded from the authors’ work that the wear rate and friction coefficient of polymer-based (such as PI, PTFE) composites in the alkali lubricated conditions is lowest among all the friction conditions. This may be attributed to the ionic hydration in the alkaline solution.


2018 ◽  
Vol 55 (1) ◽  
pp. 102-110 ◽  
Author(s):  
Marian Bastiurea ◽  
Dumitru Dima ◽  
Gabriel Andrei

Graphene oxide and graphite filled polyester composites were prepared by using conventional melt-mixing methods in order to improve tribological performance of polyester. It was investigated friction stability, microhardness, friction coefficient, and specific wear rate of the composites in details. It was found that the presence of graphite and graphene oxide influenced friction coefficient and wear rate of the composites. Graphene oxide decreased wear rate with increasing of test speed and graphite decreased wear rate for composite for all speeds. Tribological performance of the polyester/graphene composites is mainly attributed to bigger thermal conductivity for graphene, which can easily dissipate the heat which appears during the friction process at bigger forces. The positive influence of graphite on coefficient of friction (COF) of the composites is the result of the clivage of graphite layers during the loadings due to van der Waals weak bonds between the graphite layers.


2018 ◽  
Vol 18 (18) ◽  
pp. 18-23 ◽  
Author(s):  
Sandra Veličković ◽  
Slavica Miladinović ◽  
Blaža Stojanović ◽  
Ružica R. Nikolić ◽  
Branislav Hadzima ◽  
...  

Abstract Hybrid materials with the metal matrix are important engineering materials due to their outstanding mechanical and tribological properties. Here are presented selected tribological properties of the hybrid composites with the matrix made of aluminum alloy and reinforced by the silicon carbide and graphite particles. The tribological characteristics of such materials are superior to characteristics of the matrix – the aluminum alloy, as well as to characteristics of the classical metal-matrix composites with a single reinforcing material. Those characteristics depend on the volume fractions of the reinforcing components, sizes of the reinforcing particles, as well as on the fabrication process of the hybrid composites. The considered tribological characteristics are the friction coefficient and the wear rate as functions of the load levels and the volume fractions of the graphite and the SiC particles. The wear rate increases with increase of the load and the Gr particles content and with reduction of the SiC particles content. The friction coefficient increases with the load, as well as with the SiC particles content increase.


2021 ◽  
pp. 1-18
Author(s):  
Kartheesan S ◽  
B. Shahul hamid Khan ◽  
M Kamaraj ◽  
Manoj Gupta ◽  
Sravya Tekumalla

Abstract In this study, a pure magnesium material reinforced with 0.5, 1, 1.5, and 2 weight % of CaO was prepared through disintegrated melt deposition technique. Nanocomposites were investigated for their sliding wear behaviour in dry condition at room temperature. Amount of CaO, Load, sliding distance, and Sliding velocity were selected as input design parameters at their five-level in central composite design using Minitab 18.1 statistical software. The influence of design parameters on wear loss is reported through the Response Surface Methodology (RSM). ANOVA was used to confirm the soundness of the developed regression equation. The results indicate the contribution of linear, quadratic, and interaction terms of design parameters on response. 3D response surface and 2D contour plots are indicated the interaction effect. The result shows that an increase in sliding velocity contributes to a decrease in the wear loss of the composites because of the emergence of protective oxidative layer at the surfaces of the pins, which is confirmed through FESEM and EDAX analysis of the pin surfaces. Wear loss of the material decreased as amount of CaO increased. The ANOVA analysis concluded that the sliding distance and load contribute significantly to wear loss of the composites and their percentage of contribution is 64.02 % and 3.69%.


2020 ◽  
Vol 1002 ◽  
pp. 151-160 ◽  
Author(s):  
Anmar D. Mahdi ◽  
Saif S. Irhayyim ◽  
Salah F. Abduljabbar

Al7075 hybrid nanocomposites considered one of the most material utilized in modern engineering applications that required a combination of superior properties such as lightweight, high strength, excellent corrosion resistance, and high thermal conductivity. In the current study, Al7075 – 5 vol % graphite self-lubricating composite was reinforced by 0, 1.5, 2.5, 3.5, and 4.5 vol % WO3 nanoparticles in order to study the microstructural, mechanical, and wear characteristics. The classical powder metallurgy route was employed to fabricate the hybrid nanocomposites specimens. The microstructural analysis of the nanocomposites was characterized by utilizing a Field Emission Scanning Electron Microscope (FESEM) and Energy-Dispersive X-ray (EDX) analyses. Mechanical properties such as micro-hardness and diametral compressive strength were studied. Dry sliding wear test was performed under the various loads of 10, 15, 20, and 25 N at a sliding distance and sliding speed of 1810 m and 1.5 m/s, respectively. Results have revealed that the microhardness and diametral compressive strength considerably improved by increasing the WO3 content until 3.5 vol % and then slightly decreased. Besides, both the values of the wear rate and friction coefficient gradually reduced by increment the reinforcement content up to 3.5 vol % and then suddenly increases for all the applied loads. Nevertheless, the wear rate and friction coefficient were correlated positively with the applied loads. From the results obtained, graphite as solid lubricating material with WO3 nanoparticles was successfully combined into the Al7075 alloy matrix. The optimum mechanical and wear performance of the hybrid nanocomposite were revealed at 3.5 vol % content of WO3 nanoparticles.


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