Thermal stability of n-TiB2 reinforced α-Al2O3/SiC based nanocomposite sintered at 1600˚C using TG/DTA under controlled Ar atmosphere

Abstract

Innovation in material science progresses the usage of Al2O3/SiC based nanocomposites in gas turbine engine components, the harp-shaped structure of hypersonic rocket engine cutting tools for Ni, Al alloys, and clutch plate for two-wheelers. Thermal stability is one of the significant properties of gas turbine and rocket engine materials. Future engines may have to operate at very high temperature that may require high thermally stable material. In this research, an attempt is made to enhance the thermal stability of the Al2O3/SiC based nanocomposite by reinforcing 5-20 Vol. % nano Titanium Boride. Fabrication of α-Al2O3/SiC with 5-20 Vol. % n-TiB2 was carried out through pressureless sintering at 1600˚C followed by cold compaction. The fabrication process was carried out at a controlled Ar atmosphere. Thermal stability of the sintered samples was analyzed by NETZSCH STA 449F3 thermogravimetric analyzer with a heating rate of 10˚C/min and compared with Al2O3/SiC. The composite α-Al2O3/SiC/(5-20 Vol. %) n-TiB2 showed good thermal stability up to 1488˚C with 6% less mass change than Al2O3/SiC. The addition of n-TiB2 enhanced the collaboration between the atoms and postponed the decomposition temperature. The microstructure of the 20 vol % n-TiB2 added α-Al2O3/SiC was captured by 20 kV JSM-5600J Scanning Electron Microscopy and confirmed the presence of n-TiB2. Also, the presence of Ti, Si, Al, O, and B in the nanocomposite was confirmed by energy dispersive analysis of X-beams (EDS).