A method for synthesizing aluminum (AL) and alumina (AL2O3) based graded material with gravity casting

Abstract

The present invention generally relates to amethod for synthesizing aluminum (Al) and alumina (Al2O3) based graded material with gravity casting. The method comprises pre-heating a crucible to 150-200°C to reduce thermal damage to a casting; coating a cavity surface of the crucible with a refractory material or a mold wash, which prevents the casting from sticking to the crucible; melting 92.5-99.8 wt% of Aluminum in a preheated crucible for 103 minutes; adding 2.5-7.5 wt% of Alumina Nano-particles slowly in a melted aluminum and stirring for 8-10 minutes to form a mixture; and solidifying the mixture for 7-8 hours to form a functionally graded material (FGM).

Description

[0001] A METHOD FOR SYNTHESIZING ALUMINUM (AL) AND ALUMINA (AL2O3) BASED GRADED MATERIAL WITH GRAVITY CASTING

[0002] FIELD OF THE INVENTION

[0003] The present invention relates generally to the field of material synthesis and, more particularly, to a method for synthesizing graded materials composed of aluminum (Al) and alumina (A12O3) through the process of gravity casting. The invention has applications in the fabrication of composite materials with graded microstructures, which can be utilized in various industries such as aerospace, automotive, electronics, and structural components where customized mechanical and thermal properties are essential.

[0004] BACKGROUND OF THE INVENTION

[0005] Graded materials, sometimes referred to as functionally graded materials (FGMs), have witnessed increasing interest and application across numerous industries. These materials are characterized by a gradual change in composition and microstructure, leading to varied local material properties. This kind of compositional variation can be effectively tailored to yield specific functional requirements for a myriad of applications, ranging from resistance to thermal stresses to optimized wear and corrosion resistance.

[0006] Among the vast spectrum of graded materials, those based on the synthesis of aluminum (Al) and alumina (A12O3) stand out due to their unique combination of properties. Aluminum offers high ductility, electrical conductivity, and a relatively low density, making it favorable for lightweight applications. In contrast, alumina, being ceramic, provides hardness, high-temperature stability, and resistance to wear and oxidation. The synergistic combination of these two components in a graded material can lead to composite structures with enhanced mechanical and thermal properties.

[0007] Functionally graded materials (FGM) are composite materials that are designed to present a particular spatial variation of their properties. This is usually achieved by forming a compound of two components whose volume fraction is changed across a certain direction. For example, the toughness of a metal can be mated with the refractoriness of a ceramic without any compromise in the toughness of the metal or the refractoriness of the ceramic.

[0008] Despite the evident benefits of Al and Al2O3-based graded materials, the conventional methods of synthesizing these materials often involve complex procedures, costly equipment, and prolonged processing times. Thus, there has been a need for an innovative and efficient technique to produce these materials. The present invention addresses this gap by introducing a method that utilizes gravity casting, a simpler and more scalable process, to achieve the desired graded microstructures. This invention, as outlined in the field, has promising implications for industries such as aerospace, automotive, electronics, and those requiring structural components with custom-tailored properties.

[0009] SUMMARY OF THE INVENTION

[0010] The present disclosure pertains to a novel approach in the realm of material synthesis, specifically focusing on the creation of graded materials that seamlessly integrate aluminum (Al) and alumina (A12O3). This method harnesses the principles of gravity casting, offering a streamlined, efficient, and reproducible process. The resulting material exhibits a harmonized blend of properties derived from both aluminum and alumina, presenting the potential for a wide range of industrial applications.

[0011] In an embodiment, acomposition for synthesizing aluminum (Al) and alumina (A12O3) based graded material is disclosed. The composition includes 92.5-99.8 wt% of Aluminum, 2.5-7.5 wt% of Alumina Nano-particles, and 0.1-4 wt% of Manganese oxide (Mn2O3). In another embodiment, a method for synthesizing aluminum (Al) and alumina (AI2O3) based graded material with gravity casting is disclosed. The method includes pre-heating a crucible to 150- 200°C to reduce thermal damage to a casting. The method further includes coating a cavity surface of the crucible with a refractory material or a mold wash, which prevents the casting from sticking to the crucible. The method further includes melting 92.5-99.8 wt% of Aluminum in a preheated crucible for 103 minutes. The method further includes adding 2.5-7.5 wt% of Alumina Nano-particles slowly in a melted aluminum and stirring for 8-10 minutes to form a mixture. The method further includes solidifying the mixture for 7-8 hours to form a functionally graded material (FGM).

[0012] An object of the present disclosure is todesign and fabricate a gravity casting setup for the preparation of cast with desired parameters.

[0013] Another object of the present disclosure is to provide better adherence to a protective layer.

[0014] Another object of the present disclosure is to minimize interfacial stresses between different materials (e.g. due to temperature variation) FGMs allow better customization and tailoring of materials for specific tasks.

[0015] Another object of the present disclosure is toproduce different gravity cast of Aluminum with an Alumina load matrix as FGM at various parameters.

[0016] Another object of the present disclosure is to obtain the results of tensile strength, particle distribution, and surface microhardness of various testing samples taken out from gravity cast at different parameters.

[0017] Another object of the present disclosure is to investigate the effect of different parameters like the volume percentage of the Nanoparticle, and temperature on different responses like Mechanical Strength, thermal resistivity, and particle distribution.

[0018] Another object of the present disclosure is to optimize and find out the breakeven point of the test material for the optimum values of strength as well as thermal resistance property.

[0019] Yet another object of the present invention is to deliver an expeditious and costeffectivecomposite material that embodies the distinct properties of both aluminum and alumina, resulting in a material with superior characteristics suitable for various applications.

[0020] To further clarify the advantages and features of the present disclosure, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail in the accompanying drawings.

[0021] BRIEF DESCRIPTION OF FIGURES

[0022] These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read concerning the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

[0023] Figure lillustrates a flow chart of a method for synthesizing aluminum (Al) and alumina (AI2O3) based graded material with gravity casting in accordance with an embodiment of the present disclosure;

[0024] Figure 2 illustrates Table 1 depicts parameters for the experimentation;

[0025] Figure 3 illustrates anunderground open hearth furnace;

[0026] Figure 4 illustrates exemplary profiles of crucibles;

[0027] Figure 5 illustrates exemplary profiles of FGM produced through a gravity -casting process;

[0028] Figure 6 illustrates Table 2 depicts details of FGM produced from gravity casting with different parameters;

[0029] Figure 7 illustrates machining the FGM samples after gravity casting;

[0030] Figure 8 illustrates a schematic diagram of different testing samples taken out from FGM produced by gravity casting;

[0031] Figure 9 illustrates pieces of FGM after machining out testing samples; Figure 10 illustrates flat plate tumble-type tensile samples;

[0032] Figure 11 illustrates Hardness testing samples;

[0033] Figure 12 illustrates Samples of FGM for the study of particle distribution;

[0034] Figure 13 illustrates a plurality of SEM of different FGM samples;

[0035] Figure 14 illustrates a schematic diagram of a Sample of FGM for hardness test at three locations;

[0036] Figure 15 illustrates the Results of the hardness test for samples with 2.5% Alumina;

[0037] Figure 16 illustrates the Results of the hardness test for samples with 5% Alumina;

[0038] Figure 17 illustrates the Results of the hardness test for samples with 7.5% Alumina;

[0039] Figure 18 illustrates a schematic diagram of samples for the tensile strength test;

[0040] Figure 19 illustrates the Results of the tensile strength test of samples with a mass percentage of Alumina of 2.5% at 750°C, 850°C, and 1000°C;

[0041] Figure 20 illustrates the Results of the tensile strength test of samples with a mass percentage of Alumina of 5% at 750°C, 850°C, and 1000°C;

[0042] Figure 21 illustrates the Results of the tensile strength test of samples with a mass percentage of Alumina of 7.5% at 750°C, 850°C, and 1000°C;

[0043] Figure 22 illustrates the Stress-Strain curve for the mass Percentage of Alumina 2.5, at a temperatureof750°C;

[0044] Figure 23 illustrates the Stress-Strain curve for the mass Percentage of Alumina 5, at a temperatureof850°C; and

[0045] Figure 24 illustrates the Stress-Strain curve for the mass Percentage of Alumina 7.5, at a Temperature 1000°C.

[0046] Further, skilled artisans will appreciate those elements in the drawings are illustrated for simplicity and may not have necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help to improve understanding of aspects of the present disclosure. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

[0047] DETAILED DESCRIPTION:

[0048] To promote an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

[0049] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof.

[0050] Reference throughout this specification to “an aspect”, “another aspect” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, appearances of the phrase “in an embodiment”, “in another embodiment” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

[0051] The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures or components proceeded by "comprises... a" does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other components or additional devices or additional sub-systems or additional elements or additional structures or additional components.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The system, methods, and examples provided herein are illustrative only and not intended to be limiting.

[0053] Embodiments of the present disclosure will be described below in detail concerning the accompanying drawings.

[0054] In an embodiment, a composition for synthesizing aluminum (Al) and alumina (AI2O3) based graded material is disclosed. The composition includes 92.5-99.8 wt% of Aluminum, 2.5-7.5 wt% of Alumina Nano-particles, and 0.1-4 wt% of Manganese oxide (Mn2C>3).

[0055] Referring to Figure 1, a flow chart of a method for synthesizing aluminum (Al) and alumina (AI2O3) based graded material with gravity casting is illustrated in accordance with an embodiment of the present disclosure. At step 102, method 100 includes pre-heating a crucible to 150-200°C to reduce thermal damage to a casting.

[0056] At step 104, method 100 includes coating a cavity surface of the crucible with a refractory material or a mold wash, which prevents the casting from sticking to the crucible.

[0057] At step 106, method 100 includes melting 92.5-99.8 wt% of Aluminum in a preheated crucible for 103 minutes.

[0058] At step 108, method 100 includes adding 2.5-7.5 wt% of Alumina Nano-particles slowly in a melted aluminum and stirring for 8-10 minutes to form a mixture.

[0059] At step 110, method 100 includes solidifying the mixture for 7-8 hours to form a functionally graded material (FGM).

[0060] In another embodiment, the crucible is preferably a permanent graphite crucible with a lower base diameter of 150mm with shrinkage allowances under consideration of coefficient of contraction i.e. 1 to 1.3 %.

[0061] In another embodiment, a pre-heating time for the furnace and crucible is 43 minutes.

[0062] In another embodiment, method 100 further includes implementing thermocouples or infrared thermography during the process of melting Aluminum, ensuring an optimal liquid state of the metal.

[0063] In another embodiment, a mechanical stirrer or ultrasonic probe is employed for mixing Alumina Nano-particles in melted aluminum to achieve homogenous dispersion.

[0064] In another embodiment, a solidification process is directed to optimize material properties, wherein the solidification of the mixture is controlled in rate and direction.

[0065] In another embodiment, a post-process heat treatment is conducted on the solidified mixture, wherein the treatment is selected from a group consisting of annealing and aging processes.

[0066] In another embodiment, the mixture is solidified at temperatures selected from 750°C, 850°C, and 1000°C to ensure a graded structure. In another embodiment, the pre-heating of a crucible is optimized through a thermo-calc process, wherein the pre-heating temperature of the crucible is optimized by putting in a muffle furnace.

[0067] In another embodiment, a Manganese Oxide is used for a starter and additive to FGM for proper binding agent of pure aluminum (Al) and Alumina (AI2O3) based graded material.

[0068] Gravity casting process for producing FGM

[0069] The gravity process begins by preheating the mold to 150-200 °C (300-400 °F) to ease the flow and reduce thermal damage to the casting. The mold cavity is then coated with a refractory material or a mold wash, which prevents the casting from sticking to the mold and prolongs the mold's life. Any sand or metal cores are then installed and the mold is clamped shut. Molten metal is then poured into the mold. Soon after solidification the mold is opened and the casting removed to reduce the chances of hot tears.

[0070] Advantage of the Gravity casting method

[0071] The main advantages are given below:

[0072] • The product has a good surface finish and good dimensional accuracy.

[0073] • Reusable of the mold and high production rates.

[0074] • Close dimensional tolerances can be achieved by this process.

[0075] • Moreover, directional solidification is also a significant advantage of the gravity casting process.

[0076] • The fast cooling rates created by using a metal mold result in a finer grain structure than sand casting.

[0077] • Retractable metal cores can be used to create undercuts while maintaining a quick action mold.

[0078] Aluminum nanoparticles are of interest to a variety of fields including pyrotechnic, propellant, and explosive industries. Aluminum powder has been added to a range of these compositions to increase their performance by raising reaction energies, flame temperatures, and increasing blast rates. The physical and chemical properties of aluminum and especially its Nanoparticles, are favorable enough to make them applicable in a variety of applications such as alloy powder metallurgy parts for automobiles and aircraft, heat shielding coatings of aircraft, corrosion, resistant, conductive, and heat reflecting paints, conductive and decorative plastics, soldering and termite welding, pyrotechnics and military applications (rocket fuel, igniter, smokes, and tracers).

[0079] The gravity casting process will be taken into consideration for the preparation of the setup of the casting process. Initially, the synthesis of aluminum as base-graded material and Nanomaterial alumina (A12O3) will be processed by gravity casting. The mixing process for the base material i.e.99.8 % Pure Aluminum and Nano-material A12O3 Alumina Particle will be accomplished with the help of the Stirrer method through the Ex-Situ method i.e. particle addition processed externally. There are various process parameters like particle size of alumina, the mass percentage of the Nanoparticle, mechanical Strength, thermal resistivity, and particle distribution selected as responses in the gravity casting process. The effect of various process parameters on the outcome responses will be studied with the help of the design of experiments (DOE). The test samples for checking the tensile strength, hardness, and particle distribution will be taken out from the different casts produced by the gravity casting process. Moreover, the optimization of the different process parameters for different responses will be exercised by suitable optimization techniques.

[0080] Figure 2 illustrates Table 1 depicts the parameters for the experimentation.

[0081] The Aluminium (Al) and Alumina (AI2O3) particle-based graded material has been sponsored by the Institute of Technology, Gopeshwar, ChamoliUttarakhand, India, which is used to make the different FGM from the conventional gravity casting method. Different testing samples are then taken out from the FGM for mechanical and physical characterization. The steps involved in making the testing samples from gravity casting are listed as follows.

[0082] Base material and graded material: Aluminum (99.8%) and Alumina particles (size: 70-230 mesh size, mass percentage: 2.5%, 5%, 7.5%).

[0083] Casting method used: Conventional Gravity Casting Method.

[0084] Furnace- The furnace used for the gravity casting process is an underground open hearth furnace.

[0085] Fig. 2 shows a table in which general parameters of experiments conducted to prepare Functionally graded material (FGM) using gravity casting method. The parameters include the particle size of Alumina, mass percentage of the Alumina particle in Aluminium, the furnace temperature, and ambient cooling temperature to solidify the FGM thus produced by casting process.

[0086] Figure 3 illustrates an underground open hearth fiimace.Fig. 3 depicts an open hearth furnace setup used for the preparation of FGM, showing a crucible inside the furnace at desired temperature with molten form of load matrix i.e. pure aluminium mixed with Alumina Nano particles.

[0087] Figure 4 illustrates exemplary profdes of crucibles. A permanent graphite crucible with a lower base diameter of 150mm with shrinkage allowances under the consideration of coefficient of contraction i.e. l to 1.3% of the test size is used.Fig. 4 shows two images, in which the second image is of preheated crucible to 400°C to eliminate humidity and also to prevent thermal shock before pouring molten Aluminium into it to produce FGM. The first image of Fig. 4 displays three crucibles in which two crucibles have solidified FGM in it at ambient temperature and third crucible is empty which is being prepared for preheating. All the permanent graphite crucibles are coated with refractory materials to keep the casting from sticking, with a lower base diameter of 150 mm having shrinkage allowance which is calculated by considering the coefficient of contraction of 1% to 1.3% of the test size.

[0088] Figure 5 illustrates exemplary profiles of FGM produced through a gravity-casting process. The graded material taken out from the gravity casting process is shown in Fig.5. Table 2 shows the details of different graded materials produced through gravity casting. The preheating time for the furnace and crucible is 43 minutes, and the melting time of Aluminium in the crucible is 103 minutes after which Alumina Nano-particles are added slowly with continuously stirring for 8-10 minutes. The solidification time for FGM is 7-8 hours.

[0089] Fig. 5 shows a solidified FGM produced by gravity casting method with different furnace temperatures having different weight percentages of Nano particle i.e. Alumina (AI2O3).

[0090] Figure 6 illustrates Table 2 depicts details of FGM produced from gravity casting with different parameters. Fig. 6 represents a table showing the actual masses of Aluminium and Alumina Nano particles used to produce FGMS with three different weight (wt) percentages i.e. 2.5%, 5%, 7.5%, of Alumina Nano particles, at approximately three different furnace temperatures i.e. 750°C, 850°C, 1000°C, thus producing total nine different samples of FGMs.

[0091] Figure 7 illustrates the machining of the FGM samples after gravity casting. The centering and turning process are carried out on the FGM taken out from the gravity casting process.Fig. 7 displays two images where first image is of a raw casting of FGM mounted on a three jaw chuck of a lathe machine for initial machining process of FGM from which test samples were machined out further for testing and research purposes. The second image of Fig. 7 shows FGMs after initial machining process. Figure 8 illustrates a schematic diagram of different testing samples taken out from FGM produced by gravity casting. The samples for testing for different tests are taken out from the graded material as shown in the schematic diagram of machined graded material by center cutting through a power hack saw, followed by a milling operation.Fig. 8 represents a schematic diagram of FGM sample produced by gravity casting and shows from where the testing samples are machined out from it.

[0092] Figure 9 illustrates pieces of FGM after machining out testing samples. Fig. 9 shows left over pieces of FGM after machining out testing samples from it.

[0093] Figure 10 illustrates flat plate tumble-type tensile samples, flat plate tumble-type tensile samples machined out from the graded material are based on ASTM E-8 ( 100mm x 10mm x 6mm, with gauge length 32mm).

[0094] Fig. 10 displays flat plate tumble type tensile testing samples machined out from the bottom of the FGM produced by gravity casting based on ASTM-E 8 (100mm x 10mm x 6 mm, with gauge length of 32mm).

[0095] Figure 11 illustrates Hardness testing samples. A hardness test of Graded Material will be conducted on a microhardness tester machine. The diamond indenter of 1 / 16” diameter and load of 60kgf is specified for the measurement. A red dial on scale C will be used for measuring the readings, and the samples taken out from the graded material with dimensions 20mmx20mmx5mm.

[0096] Fig. 11 shows flat surface hardness testing samples with dimensions 20mm x 20mm x 5mm machined out from FGMs for micro hardness testing by using hardness testing machine with diamond indenter of 1 / 16” inch diameter having load capacity of 60kgf.

[0097] Figure 12 illustrates Samples of FGM for the study of particle distribution. The Microstructure Behavior of graded material will be conducteda Scanning Electron Microscope (SEM) with a sample size of 10mmx l0mmx5mm.

[0098] Fig. 12 shows testing samples with dimensions 10 x 10 x 5 mm machined out from FGM for studying microstructure behaviour of FGM.

[0099] Figure 13 illustrates a plurality of SEM of different FGM samples.

[0100] The particle distribution is higher at the bottom of FGM due to gravity casting. Higher temperature leads to an increase in particle distribution at the bottom due to an increase in settlement time which is because of an increase in solidification time at higher temperatures.

[0101] Fig. 13A to Fig. 131 shows different images taken at three magnifications i.e. 500X 1.00 kX and 2.5 kX of samples I to IX respectively of different FGMs for examining the micro structure behaviour of different samples of FGMs produced by gravity casting method. These images show distribution of alumina Nano-particles with black spots in the form of distribution of branches, and their intensity increases as the furnace temperature increase from 750°C to 1000°C for 2.5% wt% of Alumina Nano particles, showing broken distribution and low intensity of structure (Figs. 13A, 13B, 13C). At 5% wt of Alumina Nano particles for 750°C, 850°C, 1000°C shows more intense structure and continuous branch distribution of alumina particle (Figs. 13D and 13E). In Figs. 13F and 13G, rough images are produced due to lack of proper etching process showing no visual structure at different magnification.

[0102] Figs. 13H and 131 shows even more intense structure due to high composition i.e. 7.5% wt% with better dispersion and it is noted that the particle distribution has varied along the depth and at the bottom particle distribution is higher. This can be attributed to the solidification time being given under furnace cooling and because of gravity the particle gets more time to travel down the depth of the mould. This causes a gradation of dispersion of alumina Nano particle in aluminium matrix along depth. So this gradation is more visible in higher surface temp and higher weight percentage sample i.e. 7.5 % at 1000°C (Fig. 131). The microstructure also reveals that a honey comb structure is very clearly formed without much rupture and porosity.

[0103] Figure 14 illustrates a schematic diagram of a Sample of FGM for hardness test at three locations. Fig. 14 shows a schematic diagram of a sample of FGM for hardness test at three locations as hardness varies along the depth and composition of alumina reinforcement and surface temperatures along the depth of FGM.

[0104] Figure 15 illustrates the Results of the hardness test for samples with 2.5% Alumina.

[0105] Figs. 15, 16, and 17 shows results obtained from Rockwell hardness testing machine having diamond indenter 1 / 16” inch diameter with load capacity of 60kgf in which reading is obtained on red dial on scale C, for three different wt% samples i.e. 2.5%, 5%, 7.5% respectively. From the results it is clearly evident that for each sample, that hardness increases from top to bottom, which is due to increase in Alumina Nano-particles with the depth of the FGM due to gravity casting. Also as wt% of Alumina Nano-particles and furnace temperature increases, hardness increases.

[0106] Figure 16 illustrates the Results of the hardness test for samples with 5% Alumina.

[0107] Figure 17 illustrates the Results of the hardness test for samples with 7.5% Alumina. Due to gravity casting, the particle density is higher at the bottom of the sample, hence the hardness increases in each sample from thefirst location to thethird location of the hardness test. The hardness of the samples at higher temperatures should be high at the bottom concerning the samples at lower temperatures, due to an increase in settlement rate because of an increase in solidification time due to higher temperatures.

[0108] Figure 18 illustrates a schematic diagram of samples for the tensile strength test.Fig. 18 shows schematic diagram of a flat plate tumble type sample machined out from the bottom of the FGM, for testing its tensile strength.

[0109] Figure 19 illustrates the Results of the tensile strength test of samples with a mass percentage of Alumina of 2.5% at 750°C, 850°C, and 1000°C.Figs. 19, 20, 21 shows results of tensile strength test of samples with a wt% of 2.5% at 750°C, 850°C, 1000°C; 5% at 750°C, 850°C, 1000°C; and 7.5% at 750°C, 850°C, 1000°C, respectively, and Fig. 22, 23, 24 shows their respective curves respectively. In these results of the tensile strength, Yield Strength (YS) and Ultimate Tensile Strength (UTS) is found for all samples of FGMs. The 2.5% wt% of samples with furnace temperature of 750°C possess the YS of 19MPa, US of 35MPa and ductility of 14%. The YS and UTS in FGM sample reinforced at 2.5% of weight at furnace temperature of 850°C are smaller i.e. 19MPa and 36.5MPa with decrement in the ductility of 13% in comparison to the 750°C furnace temperature sample, but in case of 2.5% wt% sample at furnace temperature of 1000°C the YS and UTS in FGM sample boosted to 28Mpa, 40Mpa respectively and ductility also increased up to 16%. This is because reinforcing particles are accelerated towards downwards due to gravitational force, while congregated AI2O3 particles which are present in FGM samples increases the YS and UTS. In addition, there deformities can infatuate the microstructural continuity of FGM so that the ductility S-S curves FGMs samples with different weight percentage of reinforcement particles compositions shown in plot / curve Figs. 22, 23, 24. It is observed that the larger value of YS and UTS were found in the higher wt% of AI2O3 with higher furnace temperatures samples due to dispersion strength effect. Results also shows that the tensile characteristics like UTS and YS increases with the increase in AI2O3 weight percentage.

[0110] Figure 20 illustrates the Results of the tensile strength test of samples with a mass percentage of Alumina of 5% at 750°C, 850°C, and 1000°C.

[0111] Figure 21 illustrates the Results of the tensile strength test of samples with a mass percentage of Alumina of 7.5% at 750°C, 850°C, and 1000°C.

[0112] Figure 22 illustrates the Stress-Strain curve for the mass Percentage of Alumina 2.5, at a Temperature 750°C. Figure 23 illustrates the Stress-Strain curve for the mass Percentage of Alumina 5, at a Temperature 850°C.

[0113] Figure 24 illustrates the Stress-Strain curve for the mass Percentage of Alumina 7.5, at a Temperature 1000°C.

[0114] As tensile sample 2 is below sample 1, hence the tensile strength of sample 2 is higher in all the cases of FGM. This is due to an increase in particle density of Alumina at lower samples because of gravity casting. As the mass percentage of alumina particles increases, tensile strength increases. At higher temperatures, the tensile strength is higher as compared to samples at lower temperatures with the same composition of Alumina particles.

[0115] The Bulk functionally graded materials (FGM) are generally prepared by the powder metallurgy route. In this route, a complex process was used to finally prepare the FGM. The first challenge was preparing the powder of the appropriate size, then proper mixing of the powder, and finally sintering of the powder. All these steps are complex and costly.

[0116] In the proposed process natural gravity force was used for preparing the bulk FGM. Which is one kind of innovative and unique. This is the cheapest method available for producing bulk FGM.

[0117] The refractory material or mold wash has high thermal resistance to overcome the higher temperature effect and as used as a furnace lining, high resistance to corrosion and wear, high melting point, retention ofinechanical strength at high temp as well as high hardness at room temp due to which the refractory material or mold wash prevent sticking in mold. For such purposes, some recommended materials are clay, high alumina, siliceous, magnesia, aluminum magnesia, magnesium zirconium, and titanium.

[0118] Three compositions having 2.5, 5.0, and 7.5 wt % of Alumina Nano-particles and others as pure Aluminum were prepared in the proposed investigation and the Manganese Oxide is used for a starter as well as an additive to FGM for proper binding agent of pure aluminum (Al) and Alumina (AI2O3) based graded material and in this investigation, thereby have not investigated any effect of Manganese Oxide (MmO-,) on pure aluminum (Al) and Alumina (AI2O3) based graded material.

[0119] The higher percentage of alumina particles in the FGM composition, Design of Mold for castingto reduce the waste percentage of FGM, Solidification time as well, and Solidification medium / atmosphere of prepared FGM in the coming years.

[0120] The ultra-pure Al with 99.99 % purity will be beneficial for making the FGM materials.

[0121] Gravityis used to distribute the particles from the top to the bottom of the prepared composite. The use of tools in this process for mixing particles is not recommended. In the present process, the temperature of 750oC, 850oC, and lOOOoC was maintained during the solidification to ensure a graded structure. The pre-heating of a crucible can be optimized through the thermo-calc process. Apart from software, the pre-heating temperature of the crucible can be optimized through the experiment by putting it in the muffle furnace and visualizing it through microscopy.

[0122] Applications of FGM

[0123] AEROSPACE APPLICATIONS

[0124] • They have the added advantage that the metal side can be bolted onto the airframe rather than bonded as are the ceramic tiles used in the Orbiter.

[0125] • Other possible uses include combustion chamber insulation in ramjet or scramjet engines

[0126] NUCLEAR FUSION REACTORS

[0127] • Modification to heat exchangers in tokomak Fusion Reactors FUEL CELL TECHNOLOGY

[0128] • Creating a porosity gradient in the electrodes, the

[0129] • efficiency of the reaction can be maximized

[0130] OTHER APPLICATIONS

[0131] • Cutting tool insert coating

[0132] • Automobile engine

[0133] • components

[0134] • Turbine blade

[0135] • Heat exchanger

[0136] • Fire retardant doors

[0137] • Sensors

[0138] In an alternate embodiment, a study of different results obtained from various tests of characterization and synthesis of material. Writing and publishing of research articles in reputed journals. Thesis writing and submission.

[0139] The drawings and the forgoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of processes described herein may be changed and are not limited to the manner described herein. Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts necessarily need to be performed. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible. The scope of embodiments is at least as broad as given by the following claims.

[0140] Benefits, other advantages, and solutions to problems have been described above about specific embodiments. However, the benefits, advantages, solutions to problems, and any component(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or component of any or all the claims.

Claims

Claims1. A composition for synthesizing aluminum (Al) and alumina (A12O3) based graded material, the composition comprises:92.5-99.8 wt% of Aluminum;2.5-7.5 wt% of Alumina Nano-particles; and0.1-4 wt% of Manganese oxide (Mn2O3).

2. A method for synthesizing aluminum (Al) and alumina (A12O3) based graded material with gravity casting, the method comprises: pre-heating a crucible to 150-200°C to reduce thermal damage to a casting; coating a cavity surface of the said crucible with a refractory material or a mold wash, which prevents said casting from sticking to said crucible; melting92.5-99.8 wt% of Aluminum in a preheated crucible for 103 minutes; adding2.5-7.5 wt% of Alumina Nano-particles slowly in a melted aluminum and stirring for 8-10 minutes to form a mixture; and solidifyingsaid mixture for 7-8 hours to form a functionally graded material (FGM).

3. The method as claimed in claim 1, wherein said crucible is preferably a permanent graphite crucible with a lower base diameter of 150mm with shrinkage allowances under consideration of coefficient of contraction i.e. 1 to 1.3 %.

4. The method as claimed in claim 1, wherein a pre-heatingtimefora fiimaceandcrucibleis43minutes, wherein the pre-heating of a crucible is optimized through a thermocalc process, wherein the pre-heating temperature of the crucible is optimized by putting in a muffle furnace.

5. The method as claimed in claim 1, further comprises implementing thermocouples or infrared thermography during the process of melting Aluminum, ensuring an optimal liquid state of said metal.

6. The method as claimed in claim 1, wherein a mechanical stirrer or ultrasonic probe is employed for mixing Alumina Nano-particles in melted aluminum to achieve homogenous dispersion.

7. The method as claimed in claim 1, wherein a solidification process is directed to optimize material properties, wherein the solidification of the mixture is controlled in rate and direction.

8. The method as claimed in claim 1, wherein a post-process heat treatment is conducted on the solidified mixture, wherein said treatment is selected from a group consisting of annealing and aging processes.

9. The method as claimed in claims 1 and 7, wherein the mixture is solidified at temperature selected from 750°C, 850°C, and 1000°C to ensure a graded structure.

10. The method as claimed in claim 1, wherein a Manganese Oxide is used for a starter and additive to FGM for proper binding agent of pure aluminum (Al) and Alumina (A12O3) based graded material.

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