Heat Resistant Composite Materials for Aerospace Applications

Abstract

Heat resistant composites are widely used for high temperature thermal protection systems and as flame deflectors for aerospace applications. Advanced composites made of fiber reinforced polymer matrix composites because of their strength, stiffness, low weight and their excellent thermal properties made them to replace metallic components. In this study bi-directional E-glass/ phenolic and Rayon/ phenolic laminates were made by auto clave vacuum bagging process and their properties were evaluated by destructive and nondestructive testing methods. Laminate with known defect was examined by Ultrasonic method. Effect of modification of matrix system was studied on laminate properties. Composite made with modified phenolic resin was compared with conventional phenolic composite. Defect in the composite was analyzed by UT and Radiography methods. Oxy-acetylene erosion tests were carried out on laminate specimens and data was generated for ablative materials characterization. Heat resistant composites are essential for the successful launch and operation of all space vehicles. The selection of a composite material depends upon the mission of the space craft. While often the temperature capability is a major concern, the goal remains to protect the internal components at a minimal weight. This means extra insulation if the exterior material has a high heat capacity. In order to meet the mission objectives and the criteria the heat resistant material essential properties are it should have high heat of ablation, specific heat and low thermal conductivity, expansion coefficient, erosion rate. Fiber reinforced polymer matrix composite materials has constituted a major breakthrough in the construction of lightweight structures. In particular significant benefits have been realized in the aerospace sector to meet the severe performance requirements with stringent demands of reliability. Almost all aerospace structural components – airframes of fighter aircraft, helicopters, control surface and fins of civil aircraft, various planes in satellites, antennas, rocket motor casings and some complete airframes of small aircraft are witnessing an increasing use of the advanced composites. An important technological development that has contributed significantly to this growth of composites is the development of strong and stiff fibers such as Glass, Carbon and Aramid along with concurrent developments in the polymer chemistry resulting in a various polymeric materials to serve as matrix materials. In particular the versatility of the technology of the carbon fibers having various properties has played a key role in this growth. With complimentary developments in computer hardware and software technology, and in computational methods of analysis rendering help to the analyze and understand the material behavior and to provide predictive as well as design tools, the complexity of the polymer – matrix composites has been overcome to facilitate the extensive applications. Composites have the applications in many fields some of them are given in the following, since we are interested in aerospace applications it illustrated briefly.The creation of reliable heat resistant laminate composites for space applications requires precision design and proper tests. Because composite materials are necessary to meet heat resistant requirements for the aerospace applications such as nose cones, flame deflectors, airframes etc Selection of Materials: Since E-Glass V-9 is a conventional fibre for structural applications at high temperatures, it is also the insulating and since it is cheap in cost and easily available which is being used for many aerospace applications, hence it is selected.Though the