Characterisation of Ceramic Matrix Composites by Powder Metallurgy

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1 Characterisation of Ceramic Matrix Composites by Powder Metallurgy Kakatiya Institute of Technology & Science, Warangal ABSTRACT Advancement new material processing technology, natural materials have now become not enough to meet increasing demands on product capabilities and functions. The quest to seek for diverse engineering materials of many purposes has been increasing these days. Many new classes of materials have been derived to satisfy various new applications. Essence of forming composites is to obtain properties that cannot be obtained from a monolithic metal or clay. So we are looking for new material combinations with improved performance in service. This is one of the reasons why materials development is essential to reduce the cost of material procurement as well as having better results/performance. In this present paper Ceramic Matrix Composites successfully fabricated with different volume fractions after the fabrication of the Ceramic Matrix Composites different mechanical properties such as hardness, Porosity, high voltage test and compression strength are tested and in lined with the literature. Keywords Ceramic Matrix Composites, Powder metallurgy, Ceramics and mechanical properties. 1 INTRODUCTION The motivation to develop Ceramic Matrix Composites was to overcome the problems associated with the conventional technical ceramics like alumina, silicon carbide, aluminum nitride, silicon nitride they fracture easily under mechanical or thermo-mechanical loads because of cracks initiated by small defects or scratches. The crack resistance is like in glass very low. To increase the crack resistance or fracture toughness, particles (so -called mono crystalline whiskers or platelets) were embedded into the matrix. However, the improvement was limited, and the products have found application only in some ceramic cutting tools. So far only the integration of long multi-strand fibres has drastically increased the crack resistance, elongation and thermal shock resistance, and resulted in several new applications. Carbon (C), special silicon carbide (SiC), alumina (Al2O3) and mullite (Al2O3 SiO2) fibres are most commonly used for CMCs. The matrix materials are usually the same that is C, SiC, alumina and mullite. Generally, CMC names include a combination of type of fibre/type of matrix. For example, C/C stands for carbon-fiber-reinforced carbon (carbon/ carbon), or C/Sic for carbon-fibre-reinforced silicon carbide. Sometimes the manufacturing process is included, and a C/SiC composite manufactured with the liquid polymer infiltration (LPI) process (see below) is abbreviated as LPI-C/SiC. The important commercially available CMCs are C/C, C/SiC, SiC/SiC and Al2O3/Al2O3. They differ from conventional ceramics. 2 LITERATURE REVIEW: Sylvester O. Omole,et al [1] Production And Evaluation of Ceramic and Metal Matrix Composite By Powder Metallurgy: 212 microns of iron filing was mixed with the clay in different proportions and compacted. The Compressed samples were sintered in a muffle furnace at a temperature of C and was held for 2 hours. Each sample was analysed for hardness, porosity, compressive strength and abrasive strength. 619

2 Bhaskar Chandra Kandpal, et al [2] This paper discuss the Metal matrix composites, production technologies related to MMCs. In this the recent progress in production technologies of metal matrix composites is reviewed. Composite materials are often shortened to composites are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct at the macroscopic or microscopic scale within the finished structure Metal Matrix Composites (MMCs) are made of a continuous metallic matrix and one or more discontinuous reinforcing phases. S. Sulaiman, M. Sayuti et al [3] Prepared and characterized of silicon particulate reinforced composites, The mechanical properties of silicon composites were examined. There are indications that the incorporation of silicon into a single matrix which is araldite resin will stabilize mechanical properties and lowering manufacturing costs. In this research the impact strength, tensile strength, flexural strength, and hardness were studied M. Yasrebi, G. H. Kim, et al [4] were studied the properties of ceramics and clays and their various combinations so that each composition has various properties lie hardness tensile test porosity test and compressive test all the tests are drawn on a single chart K.Naresh, et al[5] Experimental Investigation on mechanical properties of coal ash reinforced glass fiber polymer matrix composites, Recently natural particle reinforcement have been receiving considerable attention as substitutes for synthetic fiber reinforcements such as glass in plastics due to their low cost, low density, acceptable specific strength, good thermal insulation properties, reduced tool wear, reduced thermal and respiratory irritation and renewable resources.. S. Sulaiman, et al [6] Prepared and characterized of silicon particulate reinforced composites, The mechanical properties of silicon composites were examined. There are indications that the incorporation of silicon into a single matrix which is araldite resin will stabilize mechanical properties and lowering manufacturing costs. In this paper they discussed the impact strength, tensile strength, flexural strength, and hardness were studied for composite material reinforced with silicon matrix. The silicon were mixed with araldite resin in different reinforcement percentages 2.1CERAMIC MATRIX COMPOSITES (CMC): Word ceramic is derived from the Greek word keramikos. Keramikos is used to refer to pottery. In general, ceramics may be defined as solid materials which exhibit very strong ionic bonding and in few cases covalent bonding. Ceramic materials are typically crystalline in nature. Ceramics are inorganic and non-metallic solids that are typically available in the form of powder materials. Monolithic ceramic materials possess several desirable properties, such as high moduli, high compressive strength, high temperature capability, high hardness and wear resistance, low thermal conductivity and chemical inertness. The high temperature proficiency of ceramics makes these materials very attractive for extremely high temperature applications. However, owing to their very low fracture toughness, ceramics are not appropriate for structural applications. When ceramic materials are subjected to mechanical or thermal loading, catastrophic failure takes place because ceramics do not exhibit plastic deformation as metals plastically deform due to their high mobility of dislocation. By definition ceramic matrix composites are materials in which one or more distinct ceramic phases are intentionally added to another, in order to enhance some property that is not possessed by the monolithic ceramic materials. In ceramic matrix composites, a given ceramic matrix is reinforced with either discontinuous reinforcement, such as particles, whiskers or chopped fibers or with continuous fibers. The basic reinforcements which are included in the ceramic matrices are carbon, 620

3 glasses, glass-ceramics, oxides and non-oxides. The main function of the matrix is to keep the reinforcing phase in the desired orientation or location and act as a load transfer media as well as protect reinforcement from the environment. Whereas, the primary aim of the reinforcement is to provide toughness to an otherwise brittle matrix. Filler materials in particle form are also sometimes added to the matrix materials during the processing of CMCs to enhance the properties such as electrical conductivity, thermal conductivity, thermal expansion and hardness. Particles with different shapes such as spherical, irregular and faceted are commonly used during the processing of CMCs. The schematic of morphology of the different particulate reinforcements is shown in Figure 2.1. Fig 2.1-Ceramic Matrix Composite 2.2 CERAMICS Ceramic is an inorganic, non-metallic, solid material comprising metal, non-metal or metalloid atoms primarily held in ionic and covalent bonds. This article gives an overview of ceramic materials from the point of view of materials science. The crystalline of ceramic materials ranges from highly oriented to semi-crystalline, vitrified, and often completely amorphous (e.g., glasses). Most often, fired ceramics are either vitrified or semivitrified as is the case with earthenware, stoneware, and porcelain. Varying crystalline and electron consumption in the ionic and covalent bonds cause most ceramic materials to be good thermal and electrical insulators (extensively researched in ceramic engineering). With such a large range of possible options for the composition/structure of a ceramic (e.g. nearly all of the elements, nearly all types of bonding, and all levels of crystallinity), the breadth of the subject is vast, and identifiable attributes (e.g. hardness, toughness, electrical conductivity, etc.) are hard to specify for the group as a whole. General properties such as high melting temperature, high hardness, poor conductivity, high module of elasticity, chemical resistance and low ductility are the norm, [1] with known exceptions to each of these rules (e.g. piezoelectric ceramics, glass transition temperature, superconductive ceramics, etc.). Many composites, such as fiberglass and carbon fiber, while containing ceramic materials, are not considered to be part of the ceramic family TYPES OF CERAMIC MATERIAL: Ceramic material is an inorganic, non-metallic, often crystalline oxide, nitride or carbide material. Some elements, such as carbon or silicon, may be considered ceramics. Ceramic materials are brittle, hard, strong in compression, weak in shearing and tension. They withstand chemical erosion that 621

4 occurs in other materials subjected to acidic or caustic environments. Ceramics generally can withstand very high temperatures, such as temperatures that range from 1,000 C to 1,600 C (1,800 F to 3,000 F). Glass is often not considered a ceramic because of its amorphous (non crystalline) character. However, glassmaking involves several steps of the ceramic process and its mechanical properties are similar to ceramic materials CRYSTALLINE CERAMICS: Crystalline ceramic materials are not amenable to a great range of processing. Methods for dealing with them tend to fall into one of two categories either make the ceramic in the desired shape, by reaction in situ, or by "forming" powders into the desired shape, and then sintering to form a solid body. Ceramic forming techniques include shaping by hand (sometimes including a rotation process called "throwing"), slip casting, tape casting (used for making very thin ceramic capacitors, e.g.), injection molding, dry pressing, and other variations. 3. METHODOLOGY 3.1 Preparation of the Ball Clay and Quartz Particles: For the present work Ball clay and Quartz particulate taken for preparation of ceramic matrix composite. Ceramic clay and quartz particles are mixed in Blender with various compositions and each composition weights 300 grams in this the clay is matrix and quartz particles are reinforcement in Clay deposit having the chemical composition shown in Table 1 was pulverized and milled after drying, in a ball mill. The milled product was sieved in a set of sieves and -200 microns size of the clay was collected for this work. quartz filing used was grinded from medium carbon steel balls. It was also sieved using a set of AFS sieves and 200 microns size was collected for use in this work. Having obtain 200 microns and 200 microns sizes respectively does not mean the entire used particle sizes was that values, but the maximum size was able to pass through 200 and 200 microns and lesser sizes are embedded in the bulk of collected sizes. Table 1 Chemical composition of clay used for the production of CMC Table 1 Chemical composition of clay used for the production CMC Kaolinite Mica Quartz Al₂Si₂O₅(OH)₄ KAl3Si3O10(OH)2 SiO2 80% 17% 3% 3.2 Mixing and Blending Bal Clay and quartz particles were mixed together with the aid of a mechanical mixer that rotates at the rate of 400 revolutions per minute (rpm) for 10 minutes on different mixing proportion shown in Figures 3.1 and 3.2. The mixing proportion to produce different samples Process in which powders of the same nominal to obtain a uniform distribution of particle sizes, i.e. powders consisting of different particle sizes are often blended to reduce porosity, (ii) for intermingling of lubricant with powders to modify metal to powder interaction during compaction 622

5 Fig:3.1Drilling machine Fig:3.2 Blender 3.3 Die Compaction Compaction is an important step in powder processing as it enables the forming of loose metal powders into required shapes with sufficient strength to withstand till sintering is completed. Compacting with the pressure of 300KN on the die so that the powders in the die get compacted up to the maximum level to get absolute results. A cylindrical sample of diameter 25.0 mm was produced and the height of the sample is 50mm was prepared by using UTM machine shown in Figure 3.3 Fig 3.3,Die compacting 3.4 Sintering: Sintering is the process of compacting and forming a solid mass of material by heat or pressure without melting it to the point of liquefaction. Sintering happens naturally in mineral deposits or as a manufacturing process used with metals, ceramics, plastics, and other materials. The atoms in the materials diffuse across the boundaries of the particles, fusing the particles together and creating one solid piece. Because the sintering temperature does not have to reach the melting point of the material, sintering is often chosen as the shaping process for materials with extremely high melting points such as tungsten and molybdenum. The study of sintering in metallurgy powder-related processes is known as powder metallurgy. An example of sintering can be observed when ice cubes in a glass of water adhere to each other, which is driven by the temperature difference between the water and the ice. Examples of pressure-driven sintering are the compacting of snowfall to a glacier, 623

6 or the forming of a hard snowball by pressing loose snow together. Sintering was done at C they were held in the furnace for 2 hours for homogenization and then allowed to cool in the furnace itself. shown in Figure 3.4 and 3.5 Fig 3.4Sintering furnace Fig 3.5 components after sintering 3.5 Compression Test A fixture is used to align the specimen in the wedge grips and the grips are therefore tightened. The wedges are inserted into the compression fixture, and if an extensometer is being used to measure strain, it is attached to the specimen. The specimen is compressed to failure. Table 2. Compression Test Results Weight proportions Ultimate strength of matrix (MPa) 20 wt% wt% Fig 3.5 UTM Machine 50 wt% wt% wt% Hardness Test Each sample was tested on Rockwell hardness testing machine with a B scale (HRB) as shown in fig Force was applied to press hardened steel ball indenter into the surface of the material. The calibrated scale on the machine measured the depth of indentation on the material and converts it to hardness measurement. The average results of the hardness values taken for three consecutive readings are shown in Table

7 Fig. 3.6 Rockwell hardness Table 3. Hardness Test Results Weight proportions of matrix Hardness 20 wt% wt% wt% wt% wt% Porosity Test The samples were initially weighed before immersion in water. The immersion was done for 24 hours before removal. They were cleaned and the new weight of the samples was taken again. The difference in weight was recorded, and the porosity was calculated as the difference in weight divided by the initial weight multiplies by 100. This forms the estimation of the percentage of pores available on which it can absorb and retain water in Result of porosity test is shown in Table 2. Table 4. Porosity Test Weight proportions of matrix wt. of specimen (conditioned) X1 gm Wt. of specimen after immersion (wet) X2 gm Wt. of specimen after immersion (reconditioned) X3 gm % increase in wt. of specimen % amount of soluble matter lost % of water absorbed 20 wt% wt% wt% wt% wt% High Voltage Testing Procedure: Electrical equipment must be capable of withstanding over voltages during operation. Thus by suitable testing procedure we must ensure that this is done. High voltage testing can be broadly classified into testing of insulating materials (samples of dielectrics) and tests on completed equipment. The tests carried out on samples of dielectric consist generally of the measurement of permittivity, dielectric loss per unit volume, and the dielectric strength of the material. The first two can be measured using the High Voltage Schering Bridge. The tests carried out on completed 625

8 equipment are the measurement of capacitance, the power factor or the total dielectric loss, the ultimate breakdown voltage and the flash-over voltage. The breakdown voltage tests on completed equipment are only done on a few samples since it permanently damages and destroys the equipment from further use. However since all equipment have to stand up to a certain voltage without damage under operating conditions, all equipment are subjected to withstand tests on which the voltage applied is about twice the normal voltage, but which is less than the breakdown voltage. Table 5: High Voltage Testing Fig 3.6 High Voltage Testing Attachment Weight proportions of matrix Voltage in V 20 wt% wt% wt% wt% wt% 1410 CONCLUSIONS From the observations of all the tests conducted, It is observed that the prepared composite materials are good in compressive strength. The specimens are good in sustaining the loads. It is conclude that these composite materials made by clay and ceramic particles can be used for constructional applications. From High voltage test it is clear that it can be used as non conductor materials. By Hardness test it confirmed that the material is harder than aluminum. From the Porosity test it may affect with water but that can be reduced by applying resin coating before sintering. REFERENCES [1] Omole SO, Barnabas AA, Akinfolarin JF. Production and evaluation of ceramic and metal matrix composite by powder metallurgy. Res. Eng. Struct. Mat., 2015; 1: [2] R.Karthik, S Sathiyamurthy, S Jayabal and K.Chidambaram, Tribological Behavior of Rice Husk and Egg Shell Hybrid Particulated Coir-Polyester Composites, IOSR Journal of Mechanical and Civil Engineering (IOSR - JMCE), Pg75-80 [3] N. Srivastavaa, V.K. Singhb, J. Bhaskar, Evaluation and Testing of Mechanical properties of wood plastic composite, International Journal of thermoplastic composite materials Volume 25 No 4 [4] W. Yan, R. J. T. Lin, and D. Bhattacharyya, Particulate reinforced rotationally molded polyethylene composites: Mixing methods and mechanical properties, Compos. Sci. Technol. 66 (13), pp [5] Bryan Bilyeu, Witold Brostow and Kevin P. Menard, Epoxy Thermosets and Their Applications III Kinetic Equations And Models, Journal of Materials Education Vol. 23 (4-6): [6] M. Sayuti, S. Sulaiman, B.T.H.T. Baharudin, M.K.A Arifin and T.R. VijayaramManufacturing and Properties of Quartz (SiO 2) Particulate Reinforced Al-11.8%Si Matrix Composites [7] W, D. Callister, Jr Materials Science and Engineering. 1997, [8] Suryanarayana,C., ed. Nonequilibrium Processing of Materials. (1999). Oxford, UK: Pergamon [9] Froes, F. H., debarbadillo, J. J., Suryanarayana, C. In: Froes, F. H., debarbadillo, J. J., eds, Structural Applications of Mechanical Alloying, Materials Park, OH: ASM International, (1990). pp [10] Bloor, D., Brook, R.J., Flemings, M. C., Mahajan, S., eds. The Encyclopedia of Advanced Materials (1994), Oxford, UK: Pergamon 626