PHASE EQUILIBRIA AND MICROSTRUCTURAL EVOLUTION IN NI-CE EUTECTIC ALLOYS

The primary objective of this research is to comprehensively investigate the microstructural characteristics and mechanical performance of near eutectic Ni-Ce alloys, particularly under room and elevated temperature conditions. These alloys hold significant promise as candidates for high-temperature applications, an area traditionally dominated by Ni-based superalloys. The manufacturing of traditional superalloys is intricate, often leading to challenges in castability. This research strives to formulate a Ni-Ce alloy composition that not only exhibits solid solution and precipitation strengthening, resulting in exceptional microstructural and mechanical properties, but is also castable. Current studies have demonstrated that binary and ternary Ni-Ce alloys exhibit exceptional strength retention when exposed to elevated temperatures. Furthermore, the addition of elements such as Al, Nb, Ti and Cr has been prioritized, with a focus on their effects on microstructural characteristics. Al and Cr contribute to oxidation resistance, while Nb, Ti and Cr contribute to solid solution strengthening and thus further enhancing the mechanical and environmental properties of these alloys. Moreover, Al promotes γ’ precipitation in this system, while Ti works as precipitation enhancer. In this research, an in-depth understanding of the alterations in microstructure and mechanical behavior exhibited by binary and ternary Ni-Ce alloys with the incorporation of other potential alloying elements has been studied. Additionally, the study investigates the microstructural and mechanical property stability of these alloys during short and prolonged exposure to elevated temperatures. This research has the potential to pave the way for the development of novel, high-performance Ni-Ce alloys suitable for demanding high-temperature applications.