| Abstract Scope |
Many materials used in the current sensing applications suffer from structural and functional issues related to high operating temperatures (up to 1600°C), alternating reducing/oxidizing atmospheres, high pressures, and corrosive environments. Therefore, there is a need for the development of alternative advanced materials, which are capable to operate under high-temperature and harsh-environments for extended hours to provide real-time, accurate sensing during industrial processes such as coal gasification, power generation, and steel/glass manufacturing. This is critical for better process control, improved efficiency, reduced environmental impact, and increased lifetime of the process units. In the present study, electroconductive ceramic composites were fabricated by incorporating 20-90 vol% of transition metal silicides (e.g. MoSi2, NbSi2, CrSi2) within refractory oxides (e.g. Al2O3, ZrO2, Cr2O3), followed by sintering at 1370°-1600°C in argon. Their phase stability, densification, microstructural evolution, oxidation behavior, and electrical properties were extensively investigated in a broad temperature range. Their degradation behavior was further evaluated as a function of the oxide phase type/volume and preoxidation temperature. After optimization of the process and compositions, thick-film ceramic composite thermocouples were fabricated for their thermoelectric performance evaluation |