Studies on Adhesive Wear Characteristics of Centrifugally Cast Functionally Graded Ceramic Reinforced Composite

Author(s):  
K. Kartik Sriram ◽  
N. Radhika ◽  
Manu Sam ◽  
Shrihari S

Functionally graded material containing LM13 aluminium alloy as matrix and alumina as reinforcement (10 wt. %) was fabricated (Φout150 × Φin90 × 100 mm) by centrifugal casting. Samples were machined from the cylindrical cast along its longitudinal axis. Variation in hardness along the radial cross-sectional wall revealed 33.7% improvement at the outer periphery due to higher presence of alumina. This zone was preferred for dry sliding wear experiments, designed based on Taguchi L27 orthogonal array by varying the process parameters like sliding velocity, sliding distance and load using pin-on-disc tribometer. Analysis of variance revealed velocity as most influential wear factor, next to load. An optimal condition to minimise adhesive wear was determined at a load of 15 N, sliding velocity of 3.5 m/s and sliding distance of 1250 m. Scanning electron microscope analysis on abraded surfaces showed formation of tribolayer at high velocities and delamination at high loads.

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Manu Sam ◽  
N. Radhika

A functionally graded Cu–10Sn–5Ni metal matrix composite (MMC) reinforced with 10 wt % of Al2O3 particles was fabricated using the centrifugal casting process with dimension Φout100 × Φin85 × 100 mm. The mechanical and wear resistance of the composite has been enhanced through heat treatment. Samples from of the inner zone (9–15 mm) were considered for heat treatment, as this zone has higher concentration of less dense hard reinforcement particles. The samples were solutionized (620 °C/60 min) and water quenched followed by aging at different temperatures (400, 450, and 550 °C) and time (1–3 h). Optimum parametric combination (450 °C, 3 h) with maximum hardness (269 HV) was considered for further analysis. Dry sliding wear experiments were conducted based on Taguchi's L27 array using parameters such as applied loads (10, 20, and 30 N), sliding distances (500, 1000, and 1500 m), and sliding velocities (1, 2, and 3 m/s). Results revealed that the wear rate increased with load and distance whereas it decreased initially and then increased with velocity. Optimum condition for maximum wear resistance was determined using signal-to-noise (S/N) ratio. Analysis of variance (ANOVA) predicted the major influential parameter as load, followed by velocity and distance. Scanning electron microscope (SEM) analysis of worn surfaces predicted the wear mechanism, observing more delamination due to increase in contact patch when applied load increased. Results infer 8% increase in hardness after heat treatment, making it suitable for load bearing applications.


Author(s):  
N Radhika ◽  
Rakesh Reghunath ◽  
Manu Sam

The functionally graded Cu-11Ni-4Si/10wt%WC composite and its alloy have been synthesized using horizontal centrifugal casting technique to compare the mechanical and tribological improvement and its utility for bearings and bushes. Microstructure analysis and mechanical tests showed 43% improvement in hardness and 160% improvement in tensile strength at inner radial distances compared to the outer composite periphery. Fractural analysis showed ductility for alloy, whereas for composites, brittleness at outer and a combination of both ductility and brittleness were observed at inner. Proportional rise in the wear rate and coefficient of friction was observed with increasing load and sliding distances for both composite and alloy. Composite showed a slight decline in the wear rate and coefficient of friction with an increase in the sliding velocity, while alloy showed a linear rise. Worn surfaces analysis of composite showed the formation of oxide layers, which reduced the coefficient of friction at higher sliding velocity, resulting in lower wear rate.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Naveed Anjum ◽  
S. L. Ajit Prasad ◽  
B. Suresha

The mechanical properties and dry sliding wear behaviour of glass fabric reinforced epoxy (G-E) composite with varying weight percentage of silicon dioxide (SiO2) filler have been studied in the present work. The influence of sliding distance, velocity, and applied normal load on dry sliding wear behaviour has been considered using Taguchi's L9orthogonal array. Addition of SiO2increased the density, hardness, flexural, and impact strengths of G-E composite. Results of dry sliding wear tests showed increasing wear volume with increase in sliding distance, load, and sliding velocity for G-E and SiO2filled G-E composites. Taguchi's results indicate that the sliding distance played a significant role followed by applied load, sliding velocity, and SiO2loading. Scanning electron micrographs of the worn surfaces of composite samples at different test parameters show smooth surface, microploughing, and fine grooves under low load and velocity. However, severe damage of matrix with debonding and fiber breakage was seen at high load and velocity especially in unfilled G-E composite.


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%.


2015 ◽  
Vol 24 (6) ◽  
pp. 096369351502400 ◽  
Author(s):  
N. Radhika ◽  
R. Raghu

Functionally graded aluminium LM25/silicon nitride composite was produced through stir casting followed by centrifugal casting and obtained a hollow cylindrical cast component with dimensions of 150 × 150 × 20 mm. The microstructural examination and the hardness test were carried out on the outer (1 mm) and inner surface (17 mm) as the function of radial distance from the outer periphery. The outer surface was observed with particle enriched region compared to inner surface and exhibited higher hardness. Hence the outer surface of the functionally graded composite was only further subjected to sliding wear test in pin-on-disc tribometer. The Central Composite Design in Response Surface Methodology was used to design the experiments for the selected parameters such as load (15–45 N), velocity (0.5–2.5 m/s) and sliding distance (500–2000 m). Regression test and Analysis of Variance were conducted to check the adequacy of the constructed model. The surface plots for wear rate showed that wear rate increased with increase in load and non-linearly varied with increase in velocity and sliding distance. Scanning Electron Microscopy analysis was conducted on the worn-out surfaces and observed mild to severe wear transition on increase of load.


2014 ◽  
Vol 10 (2) ◽  
pp. 276-287
Author(s):  
Rajesh Siriyala ◽  
A. Gopala Krishna ◽  
P. Rama Murthy Raju ◽  
M. Duraiselvam

Purpose – Since, wear is the one of the most commonly encountered industrial problems leading to frequent replacement of components there is a need to develop metal matrix composites (MMCs) for achieving better wear properties. The purpose of this paper is to fabricate aluminum MMCs to improve the dry sliding wear characteristics. An effective multi-response optimization approach called the principal component analysis (PCA) was used to identify the sets of optimal parameters in dry sliding wear process. Design/methodology/approach – The present work investigates the dry sliding wear behavior of graphite reinforced aluminum composites produced by the molten metal mixing method by means of a pin-on-disc type wear set up. Dry sliding wear tests were carried on graphite reinforced MMCs and its matrix alloy sliding against a steel counter face. Different contact stress, reinforcement percentage, sliding distance and sliding velocity were selected as the control variables and the response selected was wear volume loss (WVL) and coefficient of friction (COF) to evaluate the dry sliding performance. An L25 orthogonal array was employed for the experimental design. Optimization of dry sliding performance of the graphite reinforced MMCs was performed using PCA. Findings – Based on the PCA, the optimum level parameters for overall principal component (PC) of WVL and COF have been identified. Moreover, analysis of variance was performed to know the impact of individual factors on overall PC of WVL and COF. The results indicated that the reinforcement percentage was found to be most effective factor among the other control parameters on dry sliding wear followed by sliding distance, sliding velocity and contact stress. Finally the wear surface morphology of the composites has been investigated using scanning electron microscopy. Practical implications – Various manufacturing techniques are available for processing of MMCs. Each technique has its own advantages and disadvantages. In particular, some techniques are significantly expensive compared to others. Generally the manufacturer prefers the low cost technique. Therefore stir casting technique which was used in this paper for manufacturing of Aluminum MMCs is the best alternative for processing of MMCs in the present commercial sectors. Since the most important criteria of a dry sliding wear behavior is to provide lower WVL and COF, this study has intended to prove the application of PCA technique for solving multi objective optimization problem in wear applications like piston rings, piston rods, cylinder heads and brake rotors, etc. Originality/value – Application of multi-response optimization technique for evaluation of tribological characteristics for Aluminum MMCs made up of graphite particulates is a first-of-its-kind approach in literature. Hence PCA method can be successfully used for multi-response optimization of dry sliding wear process.


2015 ◽  
Vol 830-831 ◽  
pp. 485-488
Author(s):  
A.G. Arsha ◽  
E. Jayakumar ◽  
T.P.D. Rajan ◽  
Ballembettu Chandrasekhar Pai

A390 functionally graded material (FGM) pistons were fabricated by centrifugal casting, where the silicon particles were segregated in the head portion of the pistons by appropriate design and their density differences. Centrifugal casting offers casting of cylindrical structures with gradation in its properties. In centrifugally cast A390, a suitable die design can lead to the formation of hard primary Si particles gradually distributed towards the head region producing a particle rich zone, transition zone and matrix rich zone. Microstructure and chemical composition analysis confirms the composition gradation. Hardness and wear test results revealed that the gradation positively helps to improve the desired properties with the presence of in-situ primary silicon reinforcements.


Author(s):  
G Girish ◽  
V Anandakrishnan

In this work, the dry sliding wear behaviour of recursively friction stir processed AA7075 was investigated using a pin-on-disc wear testing apparatus. The microstructure of the processed specimen was probed using optical microscopy, transmission electron microscopy and atomic force microscopy. Experiments were conducted using Taguchi experimental design by varying three different parameters like load, sliding velocity and sliding distance, and the analysis of variance was performed to identify the influence of the parameters over the wear rate. From the main effect plot, the combination of 9.81 N of load, 2 m/s of sliding velocity and a sliding distance of 2000 m was identified as the optimum levels that minimize the wear rate. The regression model was developed to calculate the wear rate, and the validation test was performed with the optimum parameter combination and compared with the experimental results. Wear tracks were examined using field-emission scanning electron microscopy to identify the type of wear mechanism.


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.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
M. Sudheer ◽  
Ravikantha Prabhu ◽  
K. Raju ◽  
Thirumaleshwara Bhat

This study evaluates the influence of independent parameters such as sliding velocity (A), normal load (B), filler content (C), and sliding distance (D) on wear performance of potassium-titanate-whiskers (PTW) reinforced epoxy composites using a statistical approach. The PTW were reinforced in epoxy resin to prepare whisker reinforced composites of different compositions using vacuum-assisted casting technique. Dry sliding wear tests were conducted using a standard pin on disc test setup following a well planned experimental schedule based on Taguchi’s orthogonal arrays. With the signal-to-noise (S/N) ratio and analysis of variance (ANOVA) optimal combination of parameters to minimize the wear rate was determined. It was found that inclusion of PTW has greatly improved the wear resistance property of the composites. Normal load was found to be the most significant factor affecting the wear rate followed by (C), (D), and (A). Interaction effects of various control parameters were less significant on wear rate of composites.


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