NI BASED SUPERALLOY: CASTING TECHNOLOGY, METALLURGY, DEVELOPMENT, PROPERTIES AND APPLICATIONS

A superalloy, or high - performance alloy, is an alloy able to withstand extreme temperatures that would destroy conventional metals like steel and aluminum. Nickel based superalloys are selected for use in certain applications due to their characteristics. These alloys have an exceptional combination of high temperature strength, toughness, and resistance to degradation in corrosive or oxidizing environments. Among the important characteristics are creep resistance at high temperatures, good surface stability, and corrosion and oxidation resistance. Because of these characteristics they are widely used in aircraft and power - generation turbines, rocket engines, nuclear power and chemical processing plants and other challenging environments. The availability of superalloys duri ng past decades has led to a steady increase in the turbine entry temperatures, and this trend is expected to continue. New generations of superalloys can tolerate average temperatures of 1050°C with occasional excursions to temperatures as high as 1200°C, which is approximately 90% of the melting point of the material. Increased operating temperatures and higher efficiency in gas turbines and jet engines can reduce CO 2 emission, thus contributing to the slowing of climate change.