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Superalloy
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<p>A superalloy, or high-performance alloy, is an <a href="/facts/Alloy/I7w7WQWR">alloy</a> with the ability to operate at a high fraction of its melting point. Key characteristics of a superalloy include <a href="/facts/Mechanical_strength/CE77cUcB">mechanical strength</a>, <a href="/facts/Creep_(deformation)/6GtcMsBt">thermal creep deformation</a> resistance, surface stability, and <a href="/facts/Corrosion/lIC7H4we">corrosion</a> and <a href="/facts/Oxidation/Pyd5RVcj">oxidation</a> resistance. </p><p>The crystal structure is typically <a href="/facts/Face-centered_cubic/92Co7BKM">face-centered cubic</a> (FCC) <a href="/facts/Austenitic/Fzp52xYc">austenitic</a>. Examples of such alloys are <a href="/facts/Hastelloy/pQD7WHhk">Hastelloy</a>, <a href="/facts/Inconel/Hnxd677l">Inconel</a>, <a href="/facts/Waspaloy/IMKWAjzn">Waspaloy</a>, <a href="/facts/Rene_41/UdQmY5SR">Rene alloys</a>, <a href="/facts/Incoloy/4H2ajk0A">Incoloy</a>, MP98T, TMS alloys, and CMSX single crystal alloys. </p><p>Superalloy development relies on chemical and process innovations. Superalloys develop high temperature strength through <a href="/facts/Solid_solution_strengthening/lJAJ4HVe">solid solution strengthening</a> and <a href="/facts/Precipitation_strengthening/hxe4lpBj">precipitation strengthening</a> from secondary phase precipitates such as gamma prime and <a href="/facts/Carbides/xfCMTjYJ">carbides</a>. Oxidation or corrosion resistance is provided by elements such as <a href="/facts/Aluminium/7wmR8jYE">aluminium</a> and <a href="/facts/Chromium/6sVk6Uu7">chromium</a>. Superalloys are often cast as a single crystal in order to eliminate <a href="/facts/Grain_boundary_strengthening/Dao0UIh5">grain boundaries</a>, trading in strength at low temperatures for increased resistance to thermal creep. </p><p>The primary application for such alloys is in aerospace and marine <a href="/facts/Gas_turbine/JJJNwXrG">turbine engines</a>. Creep is typically the lifetime-limiting factor in gas turbine blades. </p><p>Superalloys have made much of very-high-temperature engineering technology possible. </p>