Centrifugal Casting and Characterisation of Primary Silicon and Mg2Si Dispersed Aluminium Functionally Graded Materials

2015 ◽  
Vol 830-831 ◽  
pp. 11-14
Author(s):  
P. Midhun Krishnan ◽  
Sanil Hari ◽  
E. Jayakumar ◽  
T.P.D. Rajan ◽  
K. Narayan Prabhu
Keyword(s):  
Radial Direction ◽  
Centrifugal Casting ◽  
Outer Region ◽  
Optical Emission ◽  
Primary Silicon ◽  
Spectroscopic Studies ◽  
Functionally Graded ◽  
Chemical Hardness ◽  
Primary Si ◽  
Inner Region

Aluminium based FGM rings, reinforced by in-situ primary Si and primary Si/ Mg2Si hybrid reinforcement were successfully fabricated by centrifugal casting and micro structural, chemical, hardness and corrosion characteristics were evaluated. It was observed that in Al-20Si ring the primary Si particles were present mostly in inner region and few in outer region where as in Al-20Si-3Mg ring both the primary silicon and Mg2Si were completely found in the inner region only resulting in a graded FGM structure. The hardness values were measured along radial direction of samples and variations corresponding to micro structural variation were analysed. Optical Emission spectroscopic studies have revealed the remarkable compositional changes along radial direction. Corrosion characteristics were also evaluated both in particle rich and depleted regions.

Processing of Primary Silicon and Mg2Si Reinforced Hybrid Functionally Graded Aluminum Composites by Centrifugal Casting

2012 ◽  
Vol 710 ◽  
pp. 395-400 ◽  
Author(s):  
S. Raghunandan ◽  
Jasim Akber Hyder ◽  
T.P.D. Rajan ◽  
K. Narayan Prabhu ◽  
B.C. Pai
Keyword(s):  
Centrifugal Casting ◽  
Casting Process ◽  
Primary Silicon ◽  
Shrinkage Porosity ◽  
Functionally Graded ◽  
Al Alloy ◽  
Primary Si ◽  
The Difference ◽  
Silicon Particles

In the present investigation, FGMs of mono-dispersed in-situ primary Si and their hybrids with Mg2Si reinforcements have been fabricated by the centrifugal casting process using 390 commercial Al alloy. Hard primary silicon particles are formed during the solidification of the 390 alloy and Mg2Si reinforcements are formed by the addition of varying amount of magnesium into the A390 aluminium alloy. Owing to the difference in density both primary silicon and Mg2Si gets segregated towards the inner periphery during centrifugal casting. The size of the Mg2Siin-situreinforcement phase is relatively smaller and is distributed in the edges of primary silicon particles and also individually in the matrix. Thein-situMg2Si and primary silicon can significantly increase the hardness and strength of the inner periphery of the casting. Higher Mg contents have been observed to introduce significant porosity leading to poor castings. Addition of phosphorous to the melt has led to the modification and refinement of primary Si morphology and also helped in the reduction of shrinkage porosity. Maximum hardness of 167 BHN is observed towards the inner periphery of the 390Al-2.5%Mg added in-situ composite.

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.

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.

Microstructural evolution and mechanical properties of gas-pressure-sintered Si3N4 with Yb2O3 as a sintering aid

1999 ◽  
Vol 14 (5) ◽  
pp. 1904-1909 ◽  
Author(s):  
Ki-Min Lee ◽  
Won-Ho Lee ◽  
Young-Hag Koh ◽  
Jong-Jin Choi ◽  
Hyoun-Ee Kim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Microstructural Evolution ◽  
Outer Region ◽  
Functionally Graded ◽  
Gas Pressure ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Sintering Aid ◽  
Inner Region

Microstructural evolution and mechanical properties of gas-pressure-sintered Si3N4 with 4 wt% Yb2O3 as a sintering aid were investigated. The microstructure was not uniform throughout the specimen. Extremely large elongated grains were formed at the outer region near the surface, while relatively small elongated grains were formed at the inner region of the specimen. The outer region expanded inward with the sintering time. Mechanical properties, such as flexural strength, fracture toughness, and R-curve behavior of the specimens were strongly influenced by these variations in microstructure. The fracture toughness and the R-curve behavior of the outer region were higher than those of the inner region of the same specimen. On the other hand, the strength of the inner region was higher than that of the outer region. By controlling the relative thickness of each region, Si3N4 specimens having functionally graded microstructure were obtained. The Si3N4 with such microstructure exhibited high strength, high fracture toughness, and good flaw tolerance at the same time.

Production of functionally graded SiC/Al-Cu-Mg composite by centrifugal casting

2016 ◽  
Vol 23 (2) ◽  
pp. 155-159 ◽  
Author(s):  
Ömer Savaş ◽  
Ramazan Kayıkcı ◽  
Ferit Fiçici ◽  
Murat Çolak ◽  
Gürhan Deniz ◽  
...  
Keyword(s):  
Composite Material ◽  
Centrifugal Casting ◽  
Liquid Aluminum ◽  
Outer Region ◽  
Stir Casting ◽  
Functionally Graded ◽  
Wear Properties ◽  
Reinforced Composite ◽  
Sic Particles ◽  
Reinforced Composite Material

AbstractThis study is aimed at investigating the production and wear properties of a functionally graded (FG) silicon carbide (SiC)-reinforced composite material, which was produced by stir casting followed by centrifugal casting. SiC powder (5 wt.%) was added into liquid aluminum at 750°C via stir casting, at which temperature a centrifugal force was applied to the mixture to drive the SiC particles toward the outer region of the mold. The results showed that two distinct regions formed in the cast samples after the centrifugation process. The outer region showed approximately 25% SiC particles resulting in almost SiC particle-free area in the internal region of the FG SiC-reinforced composite material. The test results showed that higher hardness and higher wear resistance could be obtained at the SiC-rich periphery of the cast FG composite material.

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.

Effect of Copper and Magnesium on the Microstructure of Centrifugally Cast Al-19%Si Alloys

2018 ◽  
Vol 930 ◽  
pp. 484-488
Author(s):  
Chester Contatori ◽  
Antônio Augusto Couto ◽  
Jan Vatavuk ◽  
Arnaldo A. Ciquielo Borges ◽  
Nelson Batista de Lima ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Molten Metal ◽  
Centrifugal Casting ◽  
Intermetallic Phase ◽  
Outer Wall ◽  
Primary Silicon ◽  
Functionally Graded ◽  
High Wear Resistance ◽  
Centrifugally Cast ◽  
Β Phase

Hypereutectic Al-Si alloys can be used in applications that require high wear resistance. Such wear resistance is achieved by the presence of hard primary silicon particles, allied to the formation of Mg2Si intermetallic phase when magnesium is added in this alloy. Centrifugal casting generates a gradient in the microstructure of hypereutectic Al-Si alloys that can favor such applications. Cylindrical components of Al-19%Si alloy containing added copper and magnesium contents were processed by centrifugal casting. The purpose of this study is to investigate the formation and segregation of particles of primary silicon (β) and Mg2Si in Al-19%Si alloy containing additions of copper and magnesium. Because the density of silicon (2.33 g/cm3) and Mg2Si (1.88 g/cm3) is lower than that of aluminum (2.67 g/cm3), centrifugal casting causes primary silicon (β) and Mg2Si particles to concentrate more at the outer wall of the centrifuged pipe. In this study, primary silicon (β) and Mg2Si particles were found to be retained at the outer wall of the pipe. It is believed that the rapid cooling of the molten metal in the region of contact with the mold, whose temperature is lower than that of the molten metal, allied to the centrifugal force, prevented the particles from migrating to the inner wall of the pipe. The microstructure shows a gradient in the distribution of these phases, enabling the production of a functionally graded material. The addition of copper and magnesium leads to the formation of Mg2Si and Al5Cu2Mg8Si6 phases, reducing the amount of primary β phase (Si) particles. In all the evaluated conditions, a tendency is also observed for a gradual increase in the segregation of silicon towards the inner wall along the entire length of the centrifuged pipe.

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).

Characterization of Al-Al2Cu functionally graded material produced by using horizontal centrifugal casting

2018 ◽  
Vol 14 (4) ◽  
pp. 647-662 ◽  
Author(s):  
Aref Mehditabar ◽  
Gholam H. Rahimi ◽  
Seyed Ebrahim Vahdat
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Radial Direction ◽  
Centrifugal Casting ◽  
High Energy ◽  
Functionally Graded ◽  
Dry Sliding Wear ◽  
Content Type ◽  
Cu Content ◽  
Scanning Electron

Purpose The purpose of this paper is to investigate the characterizations of high energy thick-walled functionally graded (FG) cylinder containing Al-26%Cu fabricated by horizontal centrifugal casting technique. Design/methodology/approach Field emission scanning electron microscopy in conjunction with image analyser software and energy dispersion spectroscopy is applied to measure the variations of constituent phase’s content and elemental ratios along the radial direction, respectively. Distributions of the FG properties are measured through hardness, CTE, E and σy along the radial direction to investigate the mechanical and physical properties corresponding to the variations in microstructure. In addition, the variations of wear rate along the thickness are evaluated through a series of dry sliding wear tests using the pin-on-disk wear machine. Moreover, scanning electron microscopy is employed to characterize the worn-out surfaces and morphology of wear debris in order to clarify the dominant operative wear mechanism. Findings Results showed that Al2Cu content gradually decreases from the inner wall containing 33.3 vol.% to outer wall containing 26.4 vol.% in the FG cylindrical shell. The elastic modulus and yield strength measured through compression tests reveal that these mechanical properties are limited up to certain value of Al2Cu. The obtained optimum value of Al2Cu content for studied Al-Al2Cu FG is almost 31 vol.%. Originality/value The obtained optimum value of Al2Cu content for studied Al-Al2Cu FG was almost 31 vol.%.

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