scholarly journals Effect of processing factors on the characteristics of centrifugal casting

2020 ◽  
Vol 7 ◽  
pp. 26 ◽  
Author(s):  
Shubhashree Mohapatra ◽  
Hrushikesh Sarangi ◽  
Upendra Kumar Mohanty
Keyword(s):  
Cooling Rate ◽  
Mechanical Performance ◽  
Centrifugal Casting ◽  
Functionally Graded ◽  
Grain Structure ◽  
Compositional Gradient ◽  
Graded Materials ◽  
Mould Material ◽  
End Use ◽  
Processing Factors

Centrifugal castings are produced by pouring liquid metal into rotating moulds. It solidifies under the influence of centrifugal forces, directed from the center to the periphery of the mould on account of mould rotation, and exhibits directionality in solidification which helps to eliminate voids and discontinuities in the resultant casting, usually encountered in gravity castings. Also, a compositional gradient is sat up in the melt which can be monitored, to produce functionally graded materials (FGMs) of choice with multi-functionality. The pouring rate, pouring temperature, mould temperature, and mould material can be suitably selected and altered in isolation or in combination, to generate a desired thermal gradient in the melt which decides its cooling rate. The cooling rate of the melt has the greatest impact on the grain structure of the casting. On the other hand, the grain structure of the casting governs its mechanical performance and decides the suitability for any specific end-use. Thus, different processing factors influence the characteristics of centrifugal casting. In the present article, a sincere attempt is made to analyze the effect of these factors and to enumerate the role played by each one of these factors in deciding the centrifugal casting characteristics.

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.

Application of Ceramics Metal Functionally Graded Materials on Green Automobiles

2007 ◽  
Vol 280-283 ◽  
pp. 1925-0 ◽  
Author(s):  
Yong Li ◽  
Song Jian ◽  
Zhi Min
Keyword(s):  
Functionally Graded Materials ◽  
Comparative Research ◽  
Mechanical Performance ◽  
Friction Pair ◽  
Functionally Graded ◽  
Graded Materials ◽  
Sealing Performance ◽  
Traditional Ceramics ◽  
External Characteristics ◽  
Made In

Ceramics metal functionally graded materials (FGM) is applied on the dual friction pair of the green automobiles. The structure and component characteristics of FGM are better, compared with traditional Ceramics. Even with the same components, FGM bears an outstanding mechanical performance and its cracking strength, toughness and fatigue strength are relatively superior. The influence of Ceramics metal functionally graded materials on the performance of automobiles are analyzed via a comparative research and comparison of the external characteristics of automobile is made in terms of mechanism. The results indicate that the power output, fuel consumption and durability are improved considerably on the green automobiles. Improvement is also made on the wearing capability, lubricity and sealing performance as well. Hence comes the reduction of friction loss and leakage loss. The principal abrasion mechanism of FGM is plastic flowing and the secondary are brittle failure and grain abrasion.

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.

Development of Compositional Gradient Simulation for Centrifugal Slurry-Pouring Methods

2009 ◽  
Vol 631-632 ◽  
pp. 455-460 ◽  
Author(s):  
Keisuke Kinoshita ◽  
Hisashi Sato ◽  
Yoshimi Watanabe
Keyword(s):  
Centrifugal Force ◽  
Functionally Graded ◽  
Green Body ◽  
Compositional Gradient ◽  
Graded Materials ◽  
Plasma Sintering ◽  
Gradient Composition ◽  
Spark Plasma ◽  
Component Particle ◽  
Sintering Method

Centrifugal slurry-pouring method has been proposed to fabricate the functionally graded materials (FGMs) with large compositional gradient. This processing method uses the two types of slurries (slurry 1 and slurry 2). The prepared slurry 1 containing one component, particle A, is firstly poured into the mold under the centrifugal force and then the slurry 2 containing two components, particle A and particle B, is poured into the mold. By this process, green body with gradient composition can be obtained and then green body will be sintered by Spark Plasma Sintering method. Finally, it is expected that FGM with gradient from 100% component A at one surface to 100% B at other surface can be fabricated. In this study, the graded distributions of the particle A and particle B within the slurry 2 under the centrifugal force were simulated analyzing the movement of particles in liquid. Moreover, Ti-SiO2 FGMs were experimentally fabricated. The Ti-SiO2 FGM has large compositional gradient on one side of FGM. However, when the size of solid-particle is small, it is difficult to form large compositional gradient in the FGM. This phenomenon obtained by experiment is in agreement with the calculated results. From this result, it is found that the centrifugal slurry-pouring method using different slurries is effective fabrication method for FGMs with large compositional gradient.

Investigation of the microstructure and thermo-mechanical properties of functionally graded materials fabricated by the vibrating centrifugal solid particle method

2021 ◽  
pp. 095440542110641
Author(s):  
Ali Hajisadeghian ◽  
Abolfazl Masoumi ◽  
Ali Parvizi
Keyword(s):  
Mechanical Properties ◽  
Solid Particle ◽  
Functionally Graded Materials ◽  
Centrifugal Casting ◽  
Particle Method ◽  
Outer Radius ◽  
Functionally Graded ◽  
Graded Materials ◽  
Sic Particles ◽  
Inner Radius

In this research, SiC/Al A413.1 functionally graded materials (FGMs) were fabricated by the vibrating centrifugal solid particle method (VCSPM), and the effects of the SiC particles on the microstructure and thermo-mechanical properties of an A413.1 aluminium alloy were investigated. The benefits of a vibration during centrifugal casting of FGMs are illustrated. After designing and fabricating the centrifugal casting machine, cylindrical FGM specimens were produced using the centrifugal solid particle method (CSPM) and VCSPM. This study used SiC particles with an average particle size from 50 to 62 μm as reinforcements to fabricate A413.1-10 wt% SiC functionally gradient composites at three annular mould speeds (900–1500 and 2100 rpm) and with or without a vibration of the mould. The Brinell hardness was measured; the yield strength (YS), ultimate tensile strength (UTS) and Young’s modulus (E) were determined by tensile testing; the density was determined by the Archimedes method; and the thermal expansion coefficients were measured with a dilatometer. A comparison of the samples produced by the conventional method and VCSPM shows a significant reduction in the porosity and an increase in the distribution gradient of the reinforcing particles for the VCSPM case. It can be concluded that in both processes, the mechanical and thermal properties improved in most cases by moving from the inner radius to the outer radius because of the movement of particles towards the outer radius from the centrifugal force. The results also show that the use of a vibration dramatically increased the rate and speed of migration of gas bubbles towards the inner radius, and the mechanical properties (hardness, YS, UTS and E) improved by moving from the inner to outer radius due to an increase in the percentage of silicon carbide particles. Upon increasing the velocity and using the VCSPM, the slope of these changes becomes steeper than those for the vibration-free mode and at low rotation speeds.

Biomimetic Design of Haute-Temperature Lightweight Ceramics: A Review

2009 ◽  
Vol 2 ◽  
pp. 73-93 ◽  
Author(s):  
Cynthia M. Chan ◽  
Andrew Ruys
Keyword(s):  
Cross Sections ◽  
Fused Silica ◽  
Functionally Graded ◽  
Compositional Gradient ◽  
Graded Materials ◽  
Thermal Expansion Coefficients ◽  
Low Thermal Expansion ◽  
Graded Layers ◽  
Graded Material ◽  
Graded Structures

Functionally graded materials (FGMs) are composite materials in which the properties are varied continuously from one face to the other via a compositional gradient. Functionally graded structures can be found in nature as evident in the cross-sections of bone, teeth and many plant stems, for example bamboo. Initially conceived for the purpose of thermal barrier coatings on spaceplanes, FGMs are finding more applications in other fields such as in polymers, biomedical and semiconductors. In this review, we take a look at two kinds of ceramics, carbon-carbon and fused silica, their properties and processing methods, as well as the possibility of incorporating them in a functionally graded material for use in high-temperature applications. Both carbon and fused silica have similarly low thermal expansion coefficients which will (1) allow the degree of thermal mismatch between the graded layers to be minimized and; (2) reduce the thermomechanical shock that will occur in the presence of a steep temperature gradient.

scholarly journals Characterization of Aluminum Alloy–Silicon Carbide Functionally Graded Materials Developed by Centrifugal Casting Process

2021 ◽  
Vol 11 (4) ◽  
pp. 1625
Author(s):  
Ioan Milosan ◽  
Tibor Bedő ◽  
Camelia Gabor ◽  
Daniel Munteanu ◽  
Mihai Alin Pop ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Functionally Graded Materials ◽  
Centrifugal Casting ◽  
Metallic Copper ◽  
Casting Process ◽  
Aluminum Carbide ◽  
Functionally Graded ◽  
Graded Materials ◽  
Sic Particles ◽  
Molten Aluminum Alloy

The continuous development of modern industries rises the necessity for functionally graded materials. This research starts from the consideration that the incorporation of SiC particles in the molten aluminum alloy can be difficult due to the very low wettability of SiC particles. In order to increase their wettability, SiC particles were covered with a layer of metallic copper. The incorporation of SiC particles into the aluminum alloy mass was performed by centrifugal casting. The secondary hypoeutectic Al-Si alloy used in this study was elaborated within the crucible of a resistors heated furnace. The metallic coating of SiC particles, in addition to the effect of increasing their wettability by molten metal, also has a role in preventing the formation of aluminum carbide in case of heating above 700 °C. A great amount of attention was paid to the parameters used during the centrifugal casting process. The results showed that adjusting the proportion of SiC particles within the composite allows us to obtain values of the thermal expansion coefficient within previously established limits. The present work demonstrates that the coating of SiC particles covered with a thin layer of metallic Cu creates the conditions to easily incorporate them into the molten Al mass, thus obtaining FGMs with controlled properties.

scholarly journals Characterization of Fabricated FG Pipe with Natural Fiber-Flyash-Epoxy using Centrifugal Casting

2019 ◽  
Vol 8 (11) ◽  
pp. 734-741 ◽  
Keyword(s):  
Fly Ash ◽  
Functionally Graded Materials ◽  
Natural Fiber ◽  
Centrifugal Casting ◽  
Functionally Graded ◽  
Powder Materials ◽  
Optimized Design ◽  
Cylindrical Pipe ◽  
Graded Materials ◽  
Banana Stem

This research presents the design of fabrication technique for hollow pipe made up of functionally graded materials and its characterization. In the first part, a horizontal centrifugal casting model is designed and developed using CATIA package. After getting an optimized design the fabrication work is performed in workshop. Different powder materials (Banana stem fiber, Jute fiber and Fly ash) are prepared by considering different chemical treatment and physical process. Different powder sizes (300µ, 150µ, 75µ, 53µ, 45µ) are considered to fabricate current functionally graded cylindrical pipe by altering their weight percentage. The different weight percentages (5%, 7.5%, 10%, 12.5%, 15% of Banana stem and 2.5%, 5%, 7.5%, 10%, 12.5% of Fly Ash) of constituents are considered for fabricating FGM cylindrical pipe. By altering the constituent of FGM material composition, twelve numbers of various functionally graded materials (FGMs) pipes are fabricated. In the second part, the material characterization is performed using different testing machines in Laboratories. Mechanical properties (Compression test and Micro hardness test) and physical properties (Density test, Water absorption test and thermal conductivity test) are investigated. Furthermore, the microstructures of the fabricated FGNF pipes are examined using Scanning Electron Microscope (SEM).

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