ABSTRACT
Superalloys are important enabling materials for modern aircraft. Although there have been different de™nitions over the years, superalloys are generally regarded as a class of high-temperature, highstrength alloys based on Group VIIIA-base elements of the periodic table, which achieve high strength and corrosion resistance for elevated-temperature service [1]. According to Ref. [2], superalloys are heat-resisting alloys based on nickel, nickel-iron, or cobalt. They exhibit a combination of mechanical strength and resistance to surface degradation, including high strength at elevated temperature; resistance to environmental attack; excellent creep resistance, stress-rupture strength, toughness, and metallurgical stability; and resistance to thermal fatigue and corrosion. Superalloys
2.1 Introduction ............................................................................................................................77 2.1.1 Microstructure ............................................................................................................ 79 2.1.2 Classi™cations ............................................................................................................. 81 2.1.3 Strengthening Mechanisms ........................................................................................ 81
2.2 Machinability of Superalloys .................................................................................................. 82 2.3 Machining Techniques for Superalloys .................................................................................. 83
2.3.1 Cutting Tool Materials ................................................................................................84 2.3.1.1 High-Speed Steel .........................................................................................84 2.3.1.2 Cemented Tungsten Carbide ........................................................................84 2.3.1.3 Ceramic Cutting Tools .................................................................................85 2.3.1.4 Cermet Cutting Tools ...................................................................................85 2.3.1.5 Cubic Boron Nitride .....................................................................................85 2.3.1.6 Whisker-Reinforced Materials .....................................................................85
