Experimental Studies and Comparison of Centrifugally Cast Cu/SiC and Cu/Si3N4 Functionally Graded Composites on Mechanical and Wear Behavior

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
N. Radhika ◽  
J. Andrew Jefferson
Keyword(s):  
Wear Rate ◽  
Radial Direction ◽  
Wear Behavior ◽  
Centrifugal Casting ◽  
Research Work ◽  
Experimental Studies ◽  
Tensile Tests ◽  
Functionally Graded ◽  
Centrifugally Cast ◽  
Inner Surface

The objective of this research work is to synthesize functionally graded Cu-11Ni-4Si/10 wt % SiC, Cu-11Ni-4Si/10 wt % Si3N4 composite using horizontal centrifugal casting method and to analyze its mechanical and adhesive wear behavior. The cast samples with dimension of Øout100 × Øin70 × 100 mm were synthesized and variation in volume of SiC and Si3N4 particles on inner (1 mm), middle (8 mm), and outer surfaces (15 mm) along radial direction of the composites was analyzed. Microstructural images revealed that inner zone of the both composites had highest distribution of reinforcement particles. Tensile tests on inner (1–7 mm) and outer (8–15 mm) zones of composites revealed that the inner zones had highest tensile and yield strength. Fractography test was conducted for both composites at inner and outer zones to observe the mode of failure. Hardness tests taken along radial direction of the composites revealed that, the inner surface had better hardness and it reduced toward outer periphery. The outer and inner surfaces of Cu/SiC were compared with Cu/Si3N4 composites and results revealed that inner surface of Cu/SiC had highest wear resistance among all surfaces of composites. It was also observed that, while increasing load, wear rate increased with it for all composites. Wear rate of composites majorly decreased while increasing the sliding velocity due to formation of tribolayer. Scanning electron microscopy (SEM) analysis carried out on worn surfaces of Cu/SiC and Cu/Si3N4 composite revealed that, plastic deformation, and plowing were the dominant wear mechanism for varied parameters.

Parametric Study of Dry Sliding Wear Behaviour of Functionally Graded Al LM25/Si3N4 Composite by Response Surface Methodology

2015 ◽  
Vol 24 (6) ◽  
pp. 096369351502400 ◽  
Author(s):  
N. Radhika ◽  
R. Raghu
Keyword(s):  
Response Surface Methodology ◽  
Wear Rate ◽  
Response Surface ◽  
Outer Surface ◽  
Sliding Wear ◽  
Centrifugal Casting ◽  
Functionally Graded ◽  
Wear Behaviour ◽  
Inner Surface ◽  
Sliding Distance

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.

Improvement of mechanical and tribological properties of centrifugally cast functionally graded copper for bearing applications

2018 ◽  
Vol 233 (9) ◽  
pp. 3208-3219 ◽  
Author(s):  
N Radhika ◽  
Rakesh Reghunath ◽  
Manu Sam
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Centrifugal Casting ◽  
Mechanical Tests ◽  
Functionally Graded ◽  
Sliding Velocity ◽  
Centrifugally Cast ◽  
Casting Technique ◽  
Mechanical And Tribological Properties ◽  
The Coefficient Of Friction

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.

scholarly journals Microstructure Characterization of Aluminium Syntactic Functionally Graded Composites Containing Hollow Ceramic Microspheres Manufactured by Radial Centrifugal Casting

2008 ◽  
Vol 587-588 ◽  
pp. 207-211 ◽  
Author(s):  
S.C. Ferreira ◽  
Alexandre Velhinho ◽  
L.A. Rocha ◽  
Francisco Manuel Braz Fernandes
Keyword(s):  
Metal Matrix ◽  
Radial Direction ◽  
Volume Fraction ◽  
Centrifugal Casting ◽  
Particle Volume Fraction ◽  
Particle Diameter ◽  
Functionally Graded ◽  
Particle Volume ◽  
Centrifugally Cast ◽  
Functionally Graded Composites

Syntactic functionally graded metal matrix composites (SFGMMC) are a class of metallic foams in which closed porosity results from the presence of hollow ceramic microspheres (microballoons), whose spatial distribution varies continuously between the inner and the outer section of the part, thus resulting in a continuous variation in properties. In this work, aluminiumbased SFGMMC rings were fabricated by radial centrifugal casting. The graded composition along the radial direction is controlled mainly by the difference in the centrifugal forces which act on the molten metal matrix and the ceramic particles, due to their dissimilar densities. In this case where the density of the SiO2-Al2O3 microballoons is lower than that of molten aluminium, the particles show a tendency to remain closer to the inner periphery of the ring. Thus the microballoon volume fraction increases along the radial direction of the ring from the outer to the inner periphery; in other words, the particle-rich zone is limited to an inner layer of the ring. Precursor conventional MMCs were prepared by stir-casting from the constituent materials, by homogeneously dispersing commercial SiO2-Al2O3 microballoons (particle size: 50 µm; particle volume fraction: 5 and 10 %) within a molten commercial Al-7Si-0.3Mg (A356) alloy. The resulting MMCs were then re-melt and centrifugally cast in order to produce the functionally graded composites. Particle gradients in the centrifugally cast composites were investigated by quantitative image analysis of optical micrographs (for the estimation of the particle volume fraction, mean particle diameter and porosity volume fraction).

Processing and Characterization of Functionally Graded In Situ Aluminum Composite

2015 ◽  
Vol 830-831 ◽  
pp. 485-488
Author(s):  
A.G. Arsha ◽  
E. Jayakumar ◽  
T.P.D. Rajan ◽  
Ballembettu Chandrasekhar Pai
Keyword(s):  
Centrifugal Casting ◽  
Wear Test ◽  
Primary Silicon ◽  
Functionally Graded ◽  
Die Design ◽  
Composition Analysis ◽  
Head Region ◽  
Aluminum Composite ◽  
Centrifugally Cast

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.

Comparison of the mechanical and wear behaviour of aluminium alloy with homogeneous and functionally graded silicon nitride composites

2018 ◽  
Vol 25 (2) ◽  
pp. 261-271 ◽  
Author(s):  
N. Radhika
Keyword(s):  
Silicon Nitride ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Outer Surface ◽  
Centrifugal Casting ◽  
Functionally Graded ◽  
Wear Behaviour ◽  
Unreinforced Alloy ◽  
Functionally Graded Composite ◽  
Uniform Dispersion

AbstractHomogeneous and functionally graded LM25 aluminium (Al) composites were fabricated by incorporating silicon nitride (10 wt%, 40 µm) particles through liquid metallurgy and centrifugal casting, respectively. The performance of these composites was compared with unreinforced alloy. The microstructural behaviour of the surfaces of unreinforced alloy, homogeneous composite and functionally graded composite (outer, middle and inner surfaces) were examined through optical microscopy. These surfaces were also evaluated for mechanical properties. An abrasive wear test was conducted on all these surfaces to determine their effect on wear rate. The microstructural results revealed a particle-rich region at the outer surface of the functionally graded composite material and uniform dispersion of reinforcement particles in the homogeneous composite. The outer region of the functionally graded composite showed greater hardness and the homogeneous composite displayed higher tensile strength. The abrasive wear rate increased with an increase in load and decreased with an increase in speed, and the particle-rich outer surface showed a lower wear rate. Scanning electron microscopy analysis revealed a particle-rich outer surface of functionally graded composite with fewer scratches. Therefore, higher wear resistance was observed at the outer periphery of functionally graded composites and this property can be well-utilised in automotive tribo-components such as in cylinder liners for improved performance.

scholarly journals Development of Functionally Graded Metal Composite (LM25-SiC) Using Centrifugal Casting Process and their Characterisation

10.29007/1zb1 ◽  
2018 ◽  
Author(s):  
Kinjal Patel ◽  
Viral Panara ◽  
Mayur Sutaria
Keyword(s):  
Grain Size ◽  
Wear Resistance ◽  
Rotation Speed ◽  
Centrifugal Casting ◽  
Research Work ◽  
Outer Region ◽  
Functionally Graded ◽  
Metal Composite ◽  
Sic Particles ◽  
Average Grain Size

The research work includes development of vertical centrifugal casting set-up for functionally graded metal composite (LM25-SiC) preparation. Material parameters like wt % of SiC Particles (2, 3.5, and 5%), average grain size of SiC particles (75, 44, and 6.5 μm) and process parameter like rotational speed of the mould (1000, 1100, 1200 RPM) are selected for characterization. Samples were tested for hardness and wear resistance to investigate the effect parameters on change of properties. Microstructure analysis was also performed. Total 11 FGM samples were made by varying different process parameters. It is found that hardness and wear resistant property improves with increase in wt% of SiC particles and mould rotation speed. It is also found that hardness and wear resistance value increases with reduction of average grain size of SiC particles. Increased mould rotation speed improves the level of distribution of reinforcing particles from inner to outer region.

MANAGEMENT OF TECHNOLOGICAL HERITAGE ACCURACY ASSEMBLY OF HIGH-PRECISION PRODUCTS

2020 ◽  
Author(s):  
Aleksandr Yamnikov ◽  
Elena Rodionova ◽  
Ivan Matveev
Keyword(s):  
Research Work ◽  
Experimental Studies ◽  
Rayleigh Distribution ◽  
Distribution Law ◽  
Initial State ◽  
Shape Accuracy ◽  
Inner Surface ◽  
Thin Walled ◽  
The Difference ◽  
Hot Rolled

The article is devoted to solving the problems of the production of thin-walled cases, where it is important to improve the accuracy of manufacturing. Based on the foregoing, it was decided to conduct research work. The technology of processing a long body from a hot-rolled thick-walled pipe using drawing is considered, which guarantees the required shape accuracy and the least effect of the properties of the initial state of the workpiece in comparison with the technology of manufacturing bodies by stamping from sheet metal. As a result of the work, it was determined that the difference in the diameter of the housing bore when basing on the pulling operation is mirrored onto the accuracy of the inner surface of the housing, and the maximum beating of the housing stem obeys the Rayleigh distribution law and fits into the tolerance with a two-fold margin. Experimental studies have shown that an increase in the accuracy of manufacturing extended bodies can be guaranteed by reducing the technological tolerance for the inner base hole of the workpiece for pulling

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

2020 ◽  
Vol 17 (4) ◽  
Author(s):  
K. Kartik Sriram ◽  
N. Radhika ◽  
Manu Sam ◽  
Shrihari S
Keyword(s):  
Adhesive Wear ◽  
Centrifugal Casting ◽  
Longitudinal Axis ◽  
Functionally Graded ◽  
Dry Sliding Wear ◽  
Sliding Velocity ◽  
Cross Sectional ◽  
Centrifugally Cast ◽  
Pin On Disc ◽  
Sliding Distance

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.

Effect of Heat Treatment on Mechanical and Tribological Properties of Centrifugally Cast Functionally Graded Cu/Al2O3 Composite

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Manu Sam ◽  
N. Radhika
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Centrifugal Casting ◽  
Casting Process ◽  
Sem Analysis ◽  
Functionally Graded ◽  
Dry Sliding Wear ◽  
Centrifugally Cast ◽  
Mechanical And Tribological Properties ◽  
Different Temperatures

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.

scholarly journals Wear Behavior of Ti6Al4V Surfaces Functionalized through Ultrasonic Vibration Turning

2021 ◽  
Author(s):  
R. Bertolini ◽  
A. Ghiotti ◽  
S. Bruschi
Keyword(s):  
Wear Rate ◽  
Titanium Alloys ◽  
Ultrasonic Vibration ◽  
Coefficient Of Friction ◽  
Biomedical Applications ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Research Work ◽  
Wear Tests

AbstractEven if titanium alloys are widely used for biomedical applications, the tendency they show to wear is a matter of concern for their durability. In this research work, Ultrasonic Vibration Turning (UVT) was used to generate texturized surfaces on Ti6Al4V cylinders for improving their wear performances. To prove that, in vitro wear tests were performed, during which the UVT-ed Ti6Al4V cylinders were made to slide against polyethylene disks to replicate a currently used biomedical pair. It was shown that the UVT-ed Ti6Al4V cylinders were characterized by enhanced performances in terms of coefficient of friction and wear rate, which were reduced to 52 and 25%, respectively, compared to polished Ti6Al4V surfaces.

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