WEDM Studies on TiB₂-15% SiC Ceramic Composite Processed Through SPS Process

Abstract

Ceramic matrix composites (CMCs) are also known as the advanced ceramics or synthetic ceramics, because the major constituent of CMC is basically synthetically produced ceramic material such as oxide, carbides, titanates. In the present study, TiB₂ microparticle was chosen as a matrix and SiC as reinforcement. The method selected for the consolidation and fabrication of CMC in this work is Spark Plasma Sintering (SPS) furnace at IIT, Madras. Synthesis and characteristics study on TiB₂ matrix and SiC reinforcement with varying volume% of 0, 5, 10, and 15 vol.% produced using the SPS furnace at 1100 °C, 40 MPa, and 10 min hold of time as the initial study. Among four processed CMCs, the CMC with 15% SiC gave good fracture toughness of 6.3 MPa√m and hardness of 22.1°GPa. Due to difficulty in machining of CMCs from conventional machining processes, Wire Electric Discharge Machining (Wire EDM) studies study was carried out on TiB₂-15% SiC CMC by varying Current (2, 3, and 4 A), Pulse ON (30, 60, and 90 µs) and Pulse OFF time (5, 10, and 15 µs). Results showed that at 4A current, 60 µs Ton, and 5 µs Toff gave maximum MRR of 0.621 mm³/sec. To reduce material wastage during machining, kerf is considered for which 3A current, 90 µs Ton, and 5 µs Toff gave least kerf of 0.28 mm for the initial wire diameter of 0.25 mm.