Experimental Investigations on Carbon Fibre Reinforced SiC (C/SiC) during Rotary Ultrasonic Machining

Abstract

Carbon fibre reinforced Silicon Carbide have widespread application in aerospace industry because of their superior properties like hardness, wear resistance, low density, high temperature resistance. The composites were fabricated by the chemical vapor infiltration technique by using carbon fibre as reinforcement and silicon carbide as matrix material. Needling technique was used to create the fibrous preform. However the use of C/SiC has been hindered seriously because of their poor machining characteristics. With an objective to improve the machining process of C/SiC composites, rotary ultrasonic milling of C/SiC composite of different densities was conducted. The effect of variation in material density, feed rate and axial depth of cut were studied by analyzing and optimizing the torque exerted during machining, material removal rate and change in surface roughness. Results shows that torque exerted during machining was increases with the axial depth of cut, feed rate and material density. Material removal rate was increases with the feed rate and axial depth of cut but it decreases with the material density. Change in surface roughness was reduces as the material density increases. Scanning electrode microscope and EDS techniques were used to characterize the structure, fractured morphology in the fabricated matrix of C/SiC composites. SEM technique also used to examine the effect of rotary ultrasonic milling on the composite’s structure.