Centrifugal Casting Technique Research Articles

Effect of Three Layered Centrifugal Casting on Tribological and Microstructural Characteristics of Mg Based Functionally Graded Material Alloy

Objectives: The aim of this study is to examine the tribological properties and microstructural of functionally graded material (FGM) composites based on magnesium (Mg) base material. Magnesium alloys are commonly employed in the development of biomaterials for implant applications owing to their favorable corrosion properties. The research objective is to produce Zn/Mo reinforced functionally graded magnesium composites using the centrifugal casting. Methods: A centrifugal process was employed to fabricate a functionally graded material (FGM) consisting of three layers with a cylindrical shape. The base material used for this FGM was Magnesium, which was alloyed with 10% of Zn and 10% of Mo. The developed FGMs have been analyzed for their mechanical and microstructural characteristics. The microstructure of the samples were analyzed via the Optical Microscope (OM). It is identified that denser particle molybdenum (Mo) have influenced the mechanical and microstructural characteristics of the FGM composites. Findings: Results recommend that, all the three layered testing’s, Mg (80%) +Zn (10%) + Mo (10%) composite exhibited favorable mechanical and microstructural properties. It is identified that denser particle of Mo which is influenced the microstructural characteristics. The alteration in micro hardness in the direction of centrifugal force is observed, and it is observed that the minimum wear loss for sliding wear samples A, B & C of Mg based FGM alloy were found to be 0.0018 g, 0.028 g and 0.031 g respectively, while the maximum wear loss for sliding wear samples A, B & C of FGM alloy were found to be 0.0021 g, 0.41 g and 0.31 g respectively. Novelty: In this study, a novel three-layered centrifugal casting technique was devised. Owing to its rapid degradability, the anticipated duration of the implants within the human body would be significantly shorter in comparison to alternative biomaterials such as Titanium and Stainless steel. Furthermore, the findings from the conducted tests strongly advocate for the utilization of this technique in biomedical implantations. Keywords: Functionally graded material (FGM), Centrifugal casting, Tribological characteristics, microstructural behavior, and bio­implants

Functionalization and Deconvolution of Tubular Ceramic Support Membrane Prepare from High Silica Spent Bleaching Earth by Centrifugal Casting

Spent Bleaching Earth (SBE) is a solid waste produced from the palm cooking oil refining industry. The commercial ceramic membranes are quite pricey, therefore SBE solid waste is possible to be an alternative for reduction of membrane material cost due to high silica content. This work demonstrates the fabrication of ceramic tubular support membrane with varied SBE addition and investigates the functionalization group of its membranes. The ceramic support membrane was prepared from regeneration SBE with varied loading composition 15 and 35 wt%. The regeneration SBE using n-Hexane as solvent. Membranes were casted into tubular configuration using centrifugal casting technique at 3000 rpm. The tubular ceramic SBE membranes were dried and followed by calcined at 900°C with heating rate 2°C/min using programable furnace for 2 h. Both of raw SBE material and membranes were analyzed using Fourier transform infrared (FTIR). The SBE material after regenerated exhibits has high Si-OH and Si-O-Si peaks over raw material. Interestingly, the fabrication ceramic support membrane with tubular configuration is successfully preparation by centrifugal casting. Ceramic SBE membrane exhibits functionalization and deconvolution the present of siloxane, Al-OH-Al, Ti-O-Ti, and Al-O bands for both of 15 and 35wt% SBE loading. It concluded this tubular ceramic support membrane from SBE has appropriated chemical functionalize properties to applicates as membrane separation.

Microstructural and Mechanical Characterization of the Mg Based Functionally Graded Material Fabricated through Centrifugal Casting Process

Objectives: The aim of this study is to examine the mechanical and microstructural properties of functionally graded material (FGM) composites based on magnesium (Mg). Magnesium alloys are commonly employed in the development of biomaterials for implant applications owing to their favorable corrosion properties. The research objective is to study the microstructural and mechanical properties and produce Zn/Mo reinforced functionally graded magnesium composites using the centrifugal casting. Methods: A triple layered cylindrical shaped Mg based functionally graded material (FGM) was fabricated through a centrifugal process from (Mg (80%) +Zn (10%) + Mo (10%) alloy. The developed FGMs have been analyzed for their mechanical and microstructural characteristics. The microstructure was analyzed via the OM AND SEM microscope. It is identified that denser particle molybdenum (Mo) have influenced the mechanical and microstructural characteristics. Findings: Results recommend that, all the three layered testing’s, Mg (80%) +Zn (10%) + Mo (10%) composite exhibited favorable mechanical and microstructural properties. It is identified that denser particle of Mo which is influenced the microstructural characteristics. The alteration in micro hardness in the direction of centrifugal force is observed, and it is perceived that top surface has higher hardness as compared to the middle and bottom region. The flexural strength of top surface sample is 254 MPa, which is 10% greater than middle surface sample and 12.36% greater than bottom surface sample. Compressive strength of 385 MPa, surpassing the middle surface sample by 17.11% and the bottom surface sample by 19.36%. Novelty: In this study, a novel three-layered centrifugal casting technique was devised. Owing to its rapid degradability, the anticipated duration of the implants within the human body is significantly shorter in comparison to alternative biomaterials such as Titanium and Stainless steel. Furthermore, the findings from the conducted tests strongly advocate for the utilization of this technique in biomedical implantations. Keywords: Functionally graded material (FGM), Centrifugal casting, Mechanical properties, Microstructural behavior and bioimplants

Characterization and thermo-mechanical analysis of centrifugally fabricated aluminium-boron carbide functionally graded composites

This research focuses on developing lightweight functionally gradient composites (FGCs) having graded distribution B4C in aluminium matrix by employing centrifugal casting technique. Two different sizes of reinforcement, that is, 100 and 50 μm was chosen to analyse its effect on the thermo mechanical properties and its distribution were analysed in this study. Advanced characterization revealed smooth graded distribution of the reinforcement across the thickness of the fabricated FGCs. The density and micro Vickers hardness test showed that they are 1.5% higher at outer periphery ensuring the graded distribution of B4C. The tensile strength was 31% higher for 50 μm sized reinforcement in the FGC, due to the increased surface area-to-volume ratio of the reinforcement. The thermal properties like thermal conductivity was 46.4% higher, thermal diffusivity was 27.8% higher for 100 μm sized reinforcement than for 50 μm sized reinforcement in the FGC. The above research work provides a new perspective on deploying aluminium based B4C graded composites for heat exchangers or fins subjected to varying thermal loads.

INFLUENCE OF NICKEL ON THE MICROSTRUCTURAL EVOLUTION AND MECHANICAL PROPERTIES OF LM6-ALLOY-BASED FUNCTIONALLY GRADED COMPOSITE TUBES

Despite the growing demand for new materials, we used the horizontal centrifugal casting technique to synthesize functionally graded composite (FGC) tubes using an LM6 alloy containing (3, 6 and 9) w/% nickel. All the fabricated tubes were evaluated for variations in microstructure, hardness and tensile properties along the radial cross-section in three distinct zones (inner, transition and outer). X-Ray diffraction (XRD) results indicated the formation of in-situ Al3Ni in all FGC tubes, and these in-situ tri-aluminides increased further with the addition of Ni. A comprehensive microstructural analysis across the tubes utilising scanning electron microscopy (SEM) images showed that gathering in-situ Al3Ni particles keeps growing nearer the outer zone, and primary Si cuboids increase in the inner zone. This accumulation of particles improved the mechanical properties at all three zones of the FGC tubes compared to the LM6 tube having no nickel. The results of the hardness investigation showed that precipitated Al3Ni in FGCs has a beneficial impact on the enhancement of hardness. Furthermore, the observed UTS improvement in the FGC tubes was clearly associated with the precipitation and strengthening action of Al3Ni intermetallic phases, while a significant reduction in elongation has been noted. Due to the influence of centrifugal force and density variation, the tube containing 9 w/% of Ni demonstrated good gradation among composite alloy-fabricated FGC tubes, with in-situ Al3Ni particles settling largely in the outer zone and primary Si particles settling primarily in the inner zone across the radial thickness.

A comparative study on mechanical and ballistic performance of functionally graded Al6061 composites reinforced with B4C, SiC, and Al2O3

In the present study, functionally graded Al6061 composites reinforced with boron carbide (B4C), silicon carbide (SiC), and alumina (Al2O3) were prepared using the stir and centrifugal casting techniques. Arc-shaped functionally graded metal (FGM) specimens were treated with a hot-rolling process to enhance their mechanical properties and obtain laminated plates. Then, the impacts of ceramic reinforcements on the density, microhardness, tensile strength, and ballistic resistance of FGMs were studied. Moreover, the microstructural properties of the specimens were analyzed to elucidate the particle gradient from the inner to the outer surface. As a result, the microstructure observations revealed that the ceramic particles are dispersed from the inner to the outer periphery of the FGMs with centrifugal acceleration. A more homogeneous particle distribution was obtained in B4C-reinforced FGM compared to those of SiC and Al2O3. The hot-rolled FGM specimen reinforced with B4C offered the lowest density. The microhardness was improved by 32% and 30.4% in the inner to outer regions of the SiC- and Al2O3-reinforced FGMs, respectively, while it was improved by 22.6% in B4C-reinforced FGM. On the other hand, the tensile strength and elongation of the B4C-reinforced FGM specimen were better than those of the SiC- and Al2O3-reinforced FGMs. In addition, the highest ballistic protection was achieved with B4C-reinforced laminated FGM at an impact speed of 664.25 m/s with a penetration depth of 14 mm, while the impact speeds of SiC- and Al2O3-reinforced FGMs were 500.88 and 435.23 m/s, respectively.

Hierarchical membrane by centrifugal casting and effects of incorporating activated carbon as pore-former

Producing ceramic asymmetric membranes usually requires several steps to prepare macroporous support and then the selective layer deposition. This process is energy and time-consuming, which is expensive. In this sense, the one-step centrifugal casting technique is an interesting alternative. Therefore, this work aimed to prepare ultrafiltration ceramic membranes by the centrifugal casting method, investigating the effect of a pore-forming agent on membrane performance. Different concentrations of activated carbon were used in the alumina suspension, and then the tubes were molded, dried, and sintered. The membranes' shrinkage, morphology, apparent porosity, hydraulic permeance, and BSA protein retention were evaluated to identify the effect of using the pore-forming agent. The membrane prepared without activated carbon rejected 91% of the BSA molecules (66 kDa), indicating its molecular weight cut-off. Using more than 2.5% of activated carbon increased the porosity and hydraulic permeance of the membranes, but at the expense of low BSA retention.

A literature review on Al-Si alloy matrix based in situ Al-Mg2Si FG-composites: Synthesis, microstructure features, and mechanical characteristics

The current study examined a comprehensive review of the literature on functionally graded composites, particularly Al-Mg2Si in situ metal matrix composites. Functionally graded Al-Si-Mg2Si in situ metal matrix composites are potential materials for meeting a variety of property demands in various components of automotive engines. The in situ formed intermetallic compound Mg2Si in Al-Si matrix exhibits a high melting temperature, low density, high hardness, a low thermal expansion coefficient, and a reasonably high elastic modulus. Due to all of aforementioned characteristics, Mg2Si is an attractive form of reinforcement that can be created in situ using a simple melt reaction approach. However, the coarse size of primary Mg2Si reinforcement in cast composites is a demerit which reduces the strength and ductility of the ultimate composite. Hence several researches have been attempted to refine the primary Mg2Si particles as well as to change the morphology of the eutectic structure. Apart from the monolithic in situ cast composites, attempts have been made to develop functionally graded (FG) composites in which the volume% of segregation of reinforcements are intentionally varied from one surface to another. These types of FG composites are economically developed by centrifugal casting technique in which Mg2Si reinforcements are segregated to inner the surface due to lower relative density with respect to the molten Al matrix. This type of graded microstructure results in higher strength, hardness and wears resistance at the inner surface of the tubular products. The as-cast microstructure and properties are significantly improved by solution treatment and aging. In the last, some of the most recent manufacturing techniques for FG-composites are addressed, along with their benefits, drawbacks, and applications. In general, all cutting-edge and detailed surveys of the present state of knowledge are included in this article.

PRODUCIBILITY OF FUNCTIONALLY GRADED AlB2/Al COMPOSITE MATERIAL

This study is intended to investigate producibility of functionally graded AlB2/Al composites which are used in the manufacture of ship machinery parts. AlB2 particles have been spontaneously formed in liquid matrix as reinforcement. A semi-solid composite (Al(l) - AlB2(s)) prepared at 850°C was solidified under a centrifugal force to grade functionally. The properties of composite materials such as hardness and microstructure have been examined. This research provided the following findings, AlB2 particles can be successfully synthesized with in situ reaction technique in molten aluminum. It was determined that the hardness value of the composites increases with increasing AlB2 reinforcement content within matrix. Functionally graded AlB2/Al composite materials can be successfully produced with centrifugal casting technique. It is also determined that AlB2 reinforcement ratio of the composite materials ranged from 0 to 7 vol. %. In addition, it was observed that the hardness values of the composites increased with the addition of reinforcement ratio.

Fabrication and characterization of homogenous and functionally graded glass fiber reinforced polymer composites

Composite materials are the most promising and distinctive materials to achieve higher strength to weight ratio, good stiffness and more cost-effectiveness The reinforcement and matrix are the two main components of any composite material. Fiber reinforced functionally graded resin-based polymer composite can be used in various applications where varying properties are desired. This paper presents the findings on physical and mechanical characteristics of glass fiber reinforced vinyl-ester based homogenous and functionally graded polymer composites. The homogenous polymer composites were fabricated by hand lay-up technique and functionally graded polymer composites were fabricated by centrifugal casting technique. The physical and mechanical characteristics like void fraction, water absorption, tensile strength, hardness, flexural strength, impact strength and microstructure were investigated to get detailed insights. The characteristics like void fraction, water absorption and tensile strength are found to be enhanced in case of homogenous polymer composite than functionally graded polymer composite, and this increase with fiber loading. Similarly, the hardness, impact strength and flexural strength are found to be increased with fiber loading in case of functionally graded polymer composite compared to homogenous polymer composite.

Investigations on noise emission from functionally graded materials based polymer spur gears

There is tremendous growth in the polymer gearing field. Polymer gears have replaced the metal gears in various fields. Polymer gears are now used for low, medium, and even for high power transmission systems, especially in automotive engineering. Noise emission from polymer gears is much less than metal gears in an application. In the present work, homogeneous and functionally graded materials (FGMs) gears are fabricated by glass fiber reinforced high-density polyethylene (HDPE) material via traditional and centrifugal casting techniques, respectively. Gears are manufactured by HDPE granules reinforced with fifteen weight percent and thirty weight percent of glass fibers. The focus of this experimental study is to examine the noise generation from the fabricated gears during the operation. Fabricated gears are run for 2 lakh cycles at different speeds and torque. The value of torque and speed are chosen within the range of 0.8–2.6 Nm and 500–1400 rpm, respectively. Experiments are performed on the polymer gear test rig. Noise emission from fabricated polymer gears is investigated for various running combinations of torque and speed.

Optimization of operation parameters in machining of functionally graded metal matrix composite using TOPSIS

Aluminium Functionally Graded Composites are the leading engineering materials due to its different gradient properties within the single element. Machining is one of the major challenging subjects in the functionally graded materials due to its gradient dissemination hard ceramic particles. The present work aims to manufacture Aluminium reinforced with 20 wt% SiC Functionally Graded Metal Matrix Composites (FGMMC) using vertical centrifugal casting technique and machining the manufactured specimen using Electric Discharge Machining (EDM) with varied level of operating parameters such as pulse current (Ip), pulse on time (Ton) and zones from the outer periphery of the specimen. The performance considered are surface roughness and overcut. Taguchi L9 orthogonal array table was designed to conduct the machining experiments. TOPSIS technique was used to find the optimum operation parameters through closeness coefficient values. The optimal setting operation parameters are pulse current 5A, pulse on time 75 μs, and zone from the outer periphery 30 mm. ANOVA revealed that the pulse on time is the most influencing operation parameters on the response continued by pulse current and zone from the outer periphery. The results showed that the mixed TOPSIS and ANOVA was the successful method to improve the machining operations.

Optimization of WEDM control parameters for machining of functionally graded Al6061-10 %Al2O3 composite

Functionally Graded Metal Matrix Composites (FGMMCs) are the advanced developing engineering substance due to its different gradient properties within the single element. Machining is one of the major challenging subjects in the FGMMCs due to its hard ceramic particles. The objective of this experimentation is to make aluminium reinforced with 10% alumina (Al2O3) FGMMC using Horizontal centrifugal casting technique and machine the fabricated specimen using Wire Electric Discharge Machining (WEDM) with varying levels of control variables such as wire feed rate (1, 2 and 3 mm/min), pulse on time (1, 2.5 and 3 μs) and pulse off time (12, 16 and 18 μs). Optimization was performed to derive the optimal output responses such as highest Material Removal Rate (MRR) and smallest Surface Roughness (Ra) using Taguchi’s technique. The optimum operation parameters obtained from this study to get the highest MRR are wire feed rate 2 mm/min, pulse on time 3 μs and pulse off time 18 μs and smallest surface roughness are wire feed rate 1 mm/min, pulse on time 3 μs and pulse off time 12 μs.

Enhancing the tensile strength of SiC reinforced aluminium-based functionally graded structure through the mixture design approach

PurposeThis article aims to study the tensile properties of a functionally graded composite structure with Al–18wt%Si alloy as the matrix material and silicon carbide (SiC) particles as the reinforcing element. More specifically, the study's primary objective is to optimize the composition of the material elements using a robust statistical approach.Design/methodology/approachIn this research, the composite material is fabricated using a combination of stir casting and the centrifugal casting technique. Moreover, the test specimen required to study the tensile strength are prepared according to the ASTM (American Society for Testing and Materials) standards. Eventually, optimal composition to maximize the tensile property of the material is determined using the mixture design approach.FindingsThe investigation results imply that the addition of the SiC plays a crucial role in increasing the tensile strength of the composite. The optical microstructural images of the composite show the adequate distribution of the reinforcing particles with the matrix. The proposed regression model shows better predictability of tensile strength. In addition, the methodology aids in optimizing the mixture component values to maximize the tensile strength of the produced functionally graded composite structure.Originality/valueLittle work has been reported so far where a hypereutectic Al–Si alloy is considered the matrix material to produce the composite structure. The article attempts to make a composite structure by using a combination of stir casting and centrifugal casting. Furthermore, it employs the mixture design to optimize the composition and predict the model of the study, which is one of a kind in the field of material science.

Effect of Grain Distribution on Resin Consumption and Mechanical Performance of GRP Pipes

It was aimed to produce GRP pipes, having less resin consumption and higher mechanical properties by changing the grain distribution of fillers used in the core region. American Foundry Society (AFS) grain fineness number currently used in GRP pipe production, and the grain distribution determined to the Fuller equation, the exponent of which is 0.8 (F0.8), were used in the study. Chopped glass fibers, unsaturated polyester resin, and silica filler were used. It was manufactured three GRP pipes having 6m length and nominal diameter (DN) of 350mm by centrifugal casting technique. Initial specific ring stiffness and longitudinal tensile strength (LTS) tests were conducted on GRP pipes. After the longitudinal tensile tests of the produced GRP pipes, SEM images were taken from the core region and the morphological analyzes of the images were made. As a result of the study, when GRP pipes are produced using 14% less resin in F0.8 grain distribution, 44.11% higher stiffness and 50.4% higher LTS was obtained than the minimum value required in the standard.

Manufacturing and Characterization of Functionally Graded Material Automotive Piston Using Centrifugal Casting Technique

The process of fabricating reliable materials according to efficient usage has become one of the most vital concerns. In this paper, the fabrication of functionally graded materials (FGMs) is the target using a specified application of an internal combustion engine piston model to achieve such a gradient. With a convenient rotational speed under the concept of centrifugal casting technique, the required gradient piston was successfully produced from two pure aluminum alloys A336 and A242 by such a new mechanical technique for having the required gradient. The percentages of internal ingredients, mainly, silicon were controlled axially through the piston. Chemical composition analysis, micro-hardness and wear resistance tests were performed to check the gradient and to know the difference between mechanical properties for each piston portion from its top combustion chamber to its skirt, achieving compatible results through performed tests. Obvious opposite direction gradient of silicon content to copper content appeared. Micro-hardness, wear resistance and coefficient of friction values showed a successfully gradient in the axial direction of the piston model.

Study on Al/TiB2 functionally graded metal matrix composites

Abstract The present work demonstrates the processing and characterization of AA6061-5 wt% TiB2 Titanium Diboride (TiB2) functionally graded metal matrix composites (FGMMCs) processed via in-situ chemical route followed by centrifugal casting technique (CCT). Microstructural analysis of the cast cylinder confirmed the presence of TiB2 particles in outer region of the cylinder and a gradient distribution of TiB2 particles was observed in the casting. FGMMCs exhibit 36% of variation in microhardness value from outer to inner region and increase of 15% in comparison with homogeneous composites. Result revealed that outer surface exhibit high wear resistance, credited to increase in volume fraction of TiB2 particles due to centrifugal force. Dimensional stability of the outer surface was found more than that of inner surface. It is due to lower CTE of the TiB2 nanoparticles present in the outer region.

Centrifugally cast A356/SiC functionally graded composite: Fabrication and mechanical property assessment

Aluminum alloy with SiC particles reinforcement, functionally graded composite cylinder is developed via horizontal centrifugal casting technique. Cylindrical specimen is fabricated with 8 wt% of SiC particles reinforcement in A356 under mould rotational speed of 800 rpm. The comparative hardness at different locations on the cylinder is measured by taking five different samples along its longitudinal direction. Present investigation results shown about 204 percent improvement in hardness obtained for functionally graded cylinder at its outer region as compared to inner zone. The hardness value and its percentage of improvement shown a leaning trend from one end to other on the surface of cylinder liner. The outer layer of functionally graded material (FGM) shown about four times increase in hardness as compared to that of as cast A356 specimens. The inner layer of FGM also showed 1.3 times enhanced hardness value in comparison to A356 alloy.

Preparation of alumina based tubular asymmetric membranes incorporated with coal fly ash by centrifugal casting

Design of new efficient membranes from sustainable sources such as coal fly ash (CFA) has been receiving rapidly growing attention. In the present work, alumina-based tubular asymmetric membranes were incorporated with different amounts of CFA using the centrifugal casting technique. The amount of CFA added to the matrix of the alumina tubes was varied from 10 to 40 wt% on a dry weight basis. The development of the ceramic membranes containing CFA comprised the following steps: raw materials dispersion, membrane preparation by centrifugal casting using high-speed mold rotation, drying of the green body followed by sintering at 1200 °C. The techniques used for membrane characterization included measuring mechanical strength, apparent porosity, morphology by scanning electron microscopy, linear shrinkage, hydraulic performance, and cornstarch retention. High CFA fraction in the alumina-based membranes resulted in higher porosity and higher water permeability, accompanied by a decrease in mechanical strength and linear shrinkage. The observed permeate flux was between 116 and 370 L m−2 h−1 bar−1, and the observed retention was above 99% for all the membranes tested. The addition of CFA for the preparation of asymmetric tubular membranes based on alumina allows utilization of industrial waste, reduces the cost and is interesting from both an economic and environmental points of view. These membranes have the potential for applications such as wastewater treatment and as a support for selective layer coatings.

New Al2O3–Cu–Ni functionally graded composites manufactured using the centrifugal slip casting

AbstractThe aim of this paper was to establish the general suitability of the centrifugal slip casting technique for fabrication of graded material from the Al2O3–Cu–Ni system. The present investigation is a preliminary one and the obtained results may be regarded as a point for acquiring the new knowledge in the ternary ceramic metal system fabricated using centrifugal slip casting. The rheological study provided the evidence that the suspension used to fabricate composites is a non‐Newtonian slurry. Moreover, the results demonstrated that the prepared slurry is stable over time. The obtained composites has a hollow cylindrical shape with relative density of > 95%. The XRD study results revealed three phases: Al2O3, Ni, and CuNi. The microscopic investigations revealed a nonhomogeneous distribution of the metallic phase in the composite. It has been shown that the content of the metallic phase decreased with the increased distance from the outside to the inner edge of the ceramic‐metal composite. The study results allow to conclude that the interface between the phases is more continuous when sintering was carried out in a solid phase. However, it was found that when sintering was carried out in a liquid phase separated metal particles with spherical phase are formed.