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.

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.

scholarly journals Mechanical Properties of Al Matrix Composite Enhanced by In Situ Formed SiC, MgAl2O4, and MgO via Casting Process

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1767
Author(s):  
Yuhong Jiao ◽  
Jianfeng Zhu ◽  
Xuelin Li ◽  
Chunjie Shi ◽  
Bo Lu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Matrix Composite ◽  
Compression Strength ◽  
Casting Process ◽  
Al Alloy ◽  
Pyrolysis Process ◽  
Alloy Matrix ◽  
Al Matrix Composite ◽  
Al Matrix

Al matrix composite, reinforced with the in situ synthesized 3C–SiC, MgAl2O4, and MgO grains, was produced via the casting process using phenolic resin pyrolysis products in flash mode. The contents and microstructure of the composites’ fracture characteristics were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Mechanical properties were tested by universal testing machine. Owing to the strong propulsion formed in turbulent flow in the pyrolysis process, nano-ceramic grains were formed in the resin pyrolysis process and simultaneously were homogeneously scattered in the alloy matrix. Thermodynamic calculation supported that the gas products, as carbon and oxygen sources, had a different chemical activity on in situ growth. In addition, ceramic (3C–SiC, MgAl2O4, and MgO) grains have discrepant contents. Resin pyrolysis in the molten alloy decreased oxide slag but increased pores in the alloy matrix. Tensile strength (142.6 ± 3.5 MPa) had no change due to the cooperative action of increased pores and fine grains; the bending and compression strength was increasing under increased contents of ceramic grains; the maximum bending strength was 378.2 MPa in 1.5% resin-added samples; and the maximum compression strength was 299.4 MPa. Lath-shaped Si was the primary effect factor of mechanical properties. The failure mechanism was controlled by transcrystalline rupture mechanism. We explain that the effects of the ceramic grains formed in the hot process at the condition of the resin exist in mold or other accessory materials. Meanwhile, a novel ceramic-reinforced Al matrix was provided. The organic gas was an excellent source of carbon, nitrogen, and oxygen to in situ ceramic grains in Al alloy.

Investigation of Functionally Graded Aluminium A356 Alloy and A356-10%SiCp Composite for Hydro Turbine Bucket Application

2016 ◽  
Vol 26 ◽  
pp. 30-46 ◽  
Author(s):  
Williams S. Ebhota ◽  
Akhil S. Karun ◽  
Freddie L. Inambao
Keyword(s):  
Heat Treatment ◽  
Tensile Stress ◽  
Centrifugal Casting ◽  
A356 Alloy ◽  
Casting Process ◽  
Ultimate Tensile Stress ◽  
Functionally Graded ◽  
Cnc Machining ◽  
Mould Material ◽  
Turbine Bucket

The study investigates the application of centrifugal casting process in the production of a complex shape component, Pelton turbine bucket. The bucket materials examined were functionally graded aluminium A356 alloy and A356-10%SiCp composite. A permanent mould for the casting of the bucket was designed with a Solidworks software and fabricated by the combination of CNC machining and welding. Oil hardening non-shrinking die steel (OHNS) was chosen for the mould material. The OHNS was heat treated and a hardness of 432 BHN was obtained. The mould was put into use, the buckets of A356 Alloy and A356-10%SiCp composite were cast, cut and machined into specimens. Some of the specimens were given T6 heat treatment and the specimens were prepared according to the designed investigations. The micrographs of A356-10%SiCp composite shows more concentration of SiCp particles at the inner periphery of the bucket. The maximum hardness of As-Cast A356 and A356-10%SiCp composite were 60 BRN and 95BRN respectively, recorded at the inner periphery of the bucket. And these values appreciated to 98BRN and 122BRN for A356 alloy and A356-10%SiCp composite respectively after heat treatment. The prediction curves of the ultimate tensile stress and yield tensile stress show the same trend as the hardness curves.

Investigation of Particle Segregation and Solidification Time in FGM's Using Centrifuge Casting Technique

2015 ◽  
Vol 766-767 ◽  
pp. 956-961
Author(s):  
K.S. Chethan ◽  
S. Kiran Aithal ◽  
A. Madhusudan ◽  
Rao Shailesh
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Particle Distribution ◽  
Centrifugal Casting ◽  
Casting Process ◽  
Functionally Graded ◽  
Particle Segregation ◽  
Graded Materials ◽  
Influence Of Process Parameters ◽  
Casting Technique

Functionally Graded Materials (FGM) is a newly evolved concept to get desired properties in the material wherein the intermediate layer is transient since the particle size distribution gradually changes. Centrifugal casting [1] can produce only hollow shapes and Centrifuge casting can produce solid shape FGM very effectively. The study of particle distribution in a fluid using centrifuge casting process is carried out considering sand as particle and its distribution is studied under water, for different viscosity values and for viscosity varying with respect to temperature. Based on centrifugal force and density difference, an attempt has been made to mathematically model the centrifuge casting force to estimate the particle distribution over the length of the specimen and also to assess the influence of process parameters such as rotational speed (G-force) and density of the particles.

Optimization of the In-Situ Al-Si Base Functionally Graded Material Fabricated by Centrifugal Casting

2001 ◽  
Vol 702 ◽  
Author(s):  
Yoshihiro Oya-Seimiya ◽  
Tetsumori Shinoda ◽  
Yoshimi Watanabe
Keyword(s):  
Functionally Graded Material ◽  
Centrifugal Casting ◽  
Functionally Graded ◽  
Outer Side ◽  
Casting Method ◽  
Graded Material ◽  
Base Composite

ABSTRACTThe fabricating conditions for the in-situ Al-Si base composite by the centrifugal casting method (CCM) have been examined. The crystallized Si particles with a lower density distribute in a gradient fashion as densely on the inner and thinly on the outer side of the wall of the cylindrical CCM-composite. Synthetically, the 25 mol% Si composite is recommended for the application like the engine liner.

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