Increased operating temperatures and higher efficiency in gas turbines and jet engines can reduce CO2 emission, thus contributing to the prevention of global warming. To achieve this goal, it is essential to improve the properties of high temperature materials

Various Ni-base superalloys are used for high-temperature components, e.g., combustors and high-pressure turbine blades and vanes, that determine the power and efficiency of jet engines and industrial gas turbines. Among them, single crystal (SC) superalloys have the highest temperature capabilities. A third-generation SC alloy has been used practically in Jet engines and fourth-generation SC alloys with platinum group metals additions are being developed for the next generation Jet engines. In land-based gas turbines also SC superalloys have been introduced to increase their inlet gas temperatures, and thus thermal efficiencies

As for new materials, intermetallic alloys, refractory alloys, ceramics, etc., are also being developed as possible alternative materials. Some unique materials have recently been proposed in Japan and being evaluated