Experimental Studies on Mechanical Properties of Glass Fiber Reinforced Ceramic Matrix Composites

Transcription

1 Experimental Studies on Mechanical Properties of Glass Fiber Reinforced Ceramic Matrix Composites A.Senthilkumar 1, L.John Baruch 2, M. Francis Luther King 3, D. George Oliver 4 1 PG Scholar, 2 Professor, 4 Assistant Professor, Department of Mechanical Engineering, PRIST University, Puducherry. 3 Professor, Department of Mechanical Engineering, Aksheyaa College of Engineering, Tamilnadu. Abstract Fiber reinforced composites are ideal materials which are used in fuselage, wings, fairings, luggage racks, doors, bulkheads and other secondary structures. In this study, the glass fiber reinforced with ceramic matrix composites laminated plate was fabricated by hand lay-up technique. Ceramics like fire clay and plaster of Paris were used as resin. The mechanical properties like tensile strength, compressive strength and bending strength were examined experimentally. Keywords-- Glass fibre, Ceramics, fireclay, plaster of paris, mechanical properties. I. INTRODUCTION Fiber- reinforced glass and glass- ceramic composites constitute a class of materials suitable for applications requiring a combination of lightweight, strength, and toughness at intermediate to elevated temperatures [1].Ceramics often display high melting point, stiffness, hardness, low density and corrosion resistence. Conversely they are intrinsically brittle and poorly reliable under load. The mechanical properties of ceramics can be significantly improved in terms of toughness, shock resistance and reliability through the use of fiber reinforcement concept which has led to new class of composite materials referred to as ceramic matrix composites CMC [2-4]. II. COMPOSITE MATERIAL Composite material is a material consisting of two or more physically and or chemically distinct phases, suitably arranged or distributed. A composite material usually has characteristics that are not depicted by any of its components in isolation [5]. Fiber reinforced composites are the combination of polymeric resins, acting as matrices or binders, with strong and stiff fiber assemblies which act as reinforcing phase [6]. A. Fiber Reinforced Composites Fiber glass composites have become an economic alternative to exotic materials. In recent years, glass fiber- reinforced plastics are being widely used in engineering applications in many different fields due to their light weight, high modulus, high specific strength and high fracture toughness [7]. The fibers are the load carrying elements and have highly oriented-defect free micro structures. The resin matrix binds the fiber together, protects fiber from the environment, provides stability to the fibers and act as a medium to transfer stresses between adjacent fibers [8]. The main material properties include anisotropy, linear elasticity to failure, high tensile strength/modulus in the direction of fibers and generally limited compressive properties [9]. III. A. Specimen Preparation EXPERIMENTAL STUDY The specimen preparation was carried out through the following procedures as given below. Materials Fire clay, plaster of paris, Araldite LY556 and Hardener HY951 was used as the matrix composition and glass fibers (TEX 2400) as reinforcing agent. Fire clay is capable of withstanding high temperature. Plaster of paris is a building material similar to cement. It gives good hardness to the composite laminate. Plaster remains quite soft after setting. The Glass fibers used is of the low alkaline E-type which gives the best long term strength and weathering properties to the fabricated part. The mechanical properties of glass fiber laminates depend chiefly on quantity, orientations of glass fiber used. It has low weight, high strength, high resistance, corrosion, strong fatigue properties, robust material, less brittle and good ability to be fabricated. Fabrication of laminate It involves the specimen preparation of standard size from bidirectional glass fiber cloth. Here hand layup technique is used to prepare the testing specimen. Raw material The laminates were made from bidirectional glass fiber consisting of resins are fire clay, plaster of Paris and Araldite LY

2 Preparation of resin Resin should be equal in weight to that of fiber is weighed and taken separately. The powdered form of fire clay has been mixed with water to form a semisolid state. This semisolid state has been mixed with araldite resin and hardener in the ratio of 10:3:1 by weight. Like fire clay another resin has been prepared by using plaster of paris with same ratio as mentioned for fire clay. Fabrication Fibers of glass are in the form of big rolls of cloth. The glass fiber mat of dimension mm was cut from big roll. The weight of all glass fibers has been measured by using an electronic weight machine. Place the mould on the table and apply a thin plastic sheet on the mould called Mila film. Apply a thin layer of resin on the surface of the lower mould. Next place the first layer of glass fiber and use the roller to squeeze the excess resin. Apply the resin over the first layer of glass fiber and then place the second layer and again use the roller to squeeze the excess resin. Repeat the procedure with alternatively layers of glass fiber and resin mixture until all the glass fibers were finished (Fig. 1 and Fig.2) Curing The time and temperature required to attain the desired properties which can be varied by the selection of the system composition. All the specimens were cured at room temperature in the fabrication stand. E. Compression test In compression test the maximum compressive strength has been found. The dimensions of the specimen for compression test are 14 14mm. Here also load Vs deflection is recorded in the machine. Fig. 1 Laminated Plate of Fire Clay Fig. 2 Laminated plate of plaster of paris B. Cutting of Specimen An electrical motor driven marble cutting machine has been used for the cutting purpose. The specimens were fabricated from the hand layup fabricated panels with following special precautions. During cutting for tensile testing samples, the ASTM standard 3039-D has been followed. C. Experimental Set up The servo Hydraulic Universal Testing Machine having a maximum capacity of 200 KN has been used. Tensile tests, compressive tests and bending tests were carried in the same machine. D. Tensile test During the tensile test, the ASTM standard specimens as mentioned above was striped at two fixtures of the machine and load is applied as per the ASTM standard recommends till the sample was failed into two segments. During the process, the load Vs deflection is recorded in the machine and converted into the stress strain diagram. Fig.3 After tensile test of fire clay Fig. 4 After tensile test of plaster of paris 678

3 Fig. After bending test of plaster of paris Fig. 6 After bending of fire clay Fig. 7 After compressive test of fire clay Table 1 and Fig. 9 shows the tensile properties of the fire clay. For tensile test the specimen should be in 300 mm length and 25 mm width. Table 2 and Fig. 10 shows the tensile properties of the plaster of Paris. Average breaking load for fire clay & plaster of paris is 14 kn and 13 kn respectively. Average tensile strength for fire clay and plaster of paris is 152 Mpa and 145 Mpa. Table 3 and Fig. 11, Table 4 and Fig. 12 shows the compressive properties of the fire clay & plaster of paris. In compression test the size of each specimen is area 14mm 14mm. The avg. breaking load for fire clay is 26 KN and for plaster of paris is 28 KN. And the avg compression strength is 141 Mpa for fire clay and 143 Mpa for plaster of paris. Table 5 and Fig. 13, Table 6 and Fig. 14 shows the flexural properties of fire clay and plaster of paris. Here we used the test specimen size is 75mm length and 12mm width. Here we applied the load in Newton. The avg breaking load for fire clay is 170 N and for plaster of paris is 161 N. the avg flexural strength of the fire clay is 68 Mpa and for plaster of paris is 61 Mpa. Table 1 Tensile properties of glass fibre reinforced fire clay Load Tensile Table 2 Tensile properties of glass fibre reinforced plaster of paris Fig. 8 After compressive test of plaster of paris IV. RESULTS The mechanical properties of laminated plates were analyzed in terms of experimental methods. The following tables and graphs shown the properties of tensile, compressive and flexural of glass fibre reinforced with fire clay, plaster of paris. Fig 3 to Fig 8 shows the variation of tensile, compressive and flexural properties between various resins like fire clay and plaster of paris load Tensile strength Table 3 Compressive properties of glass fibre reinforced fire clay Area Load Compressive

4 Table 4 Compressive properties of glass fibre reinforced plaster of paris Area Load Compressive Table 5 Bending properties of glass fibre reinforced fire clay Load (N) (N) Flexural Table 6 Bending properties of glass fibre reinforced plaster of paris Fig. 10 Variation of Tensile with Plaster of Paris Load (N) (N) 1676 Flexural Fig. 11 Variation of Compressive with Fire Clay Fig. 12 Variation of Compressive with Plaster of Paris Fig. 9 Variation of Tensile of Fire Clay 680

5 Fig. 13 Variation of Flexural with Fire Clay Fig. 14 Variation of Flexural with Plaster of Paris. V. CONCLUSIONS The glass fiber reinforced with ceramic matrix composites were fabricated by hand layup technique. Fire clay have good strengthening, good stiffness and have good thermal expansion. Plaster of paris also gives good toughening and stiffness. The mechanical properties of glass fiber reinforced with ceramic matrix composites can be greatly improved by addition of fire clay and plaster of paris. The results we obtained from the graphs, both tensile and compressive strength of fire clay and plaster of paris has been improved. The flexural strength of both fire clay and plaster of paris is good when compare to other properties. And also it is observed that the plaster of paris has good compression strength than the fire clay. The breaking load and compression strength are high for plaster of paris. But in the case of tensile and flexural, fire clay has high strength than plaster of paris. Fire clay can withstand more than 700 C and it has good thermal expansion. Finally it is found that the plaster of paris has good compression strength. Fire clay has good tensile strength and flexural strength. REFERENCES [1] Chawla KK. Ceramic matrix composites. London: Chapman and Hall, 199 [2] Aveston J., Cooper G.A., Kelly A., Single and multiple fracture, (w:) The properties of composites, IPC Science and Technolgy Press, Guildford (UK) 1971, [3] Warren R., Ceramic Matrix Composites, Blackie, Glasgow 199 [4] Evans A.G., Perspective on the development of high toughness ceramics, J. Amer. Ceram. Soc. 1990, 73, [5] Al-Mosawi, A. I., Ammash, H.K. and Salaman, A.J. (2012). Properties of Composite Materials Databook. 2nd edition, Lambert Academic Publishing LAP. [6] Tuakta C.: Use of Fiber Reinforced Polymer Composite in Bridge Structures, Massachusetts Institute of Technology, 200 [7] W.F. Smith, Principles of materials science and engineering (MacGraw-Hill, 1990). [8] Bunsell A.R., Renard J., Fundamentals of Fibre Reinforced Composite Materials.Inst. of Phys. Publ. Ltd., Bristol, UK, 200 [9] Nanni, A. (1995). Concrete Repair with Externally Bonded FRP Reinforcement. Concrete International, June, pp