IJSRD - International Journal for Scientific Research & Development| Vol. 2, Issue 09, 2014 | ISSN (online): 2321-0613 All rights reserved by www.ijsrd.com 128 Study of Nickal based Super Alloy Kheer Sagar Naik 1 Tarun Kumar Painkra 2 Rajendra Kumar Nishad 3 Prakash Kumar Sen 4 Shailendra Kumar Bohidar 5 1,2,3 B. E. (Student) 4,5 Faculty 1,2,3,4,5 Department of Mechanical Engineering 1,2,3,4,5 Kirodimal Institute of Technology, Raigarh C.G. Raigarh, Chhattisgarh, India Abstract— Super alloys are metallic materials for service at high temperature, so one of their most important properties is high temperature creep resistance. Other crucial material properties are fatigue life, phase stability, as well as oxidation and corrosion resistance. A conventional metal may be failed in high temperature machining condition and has poor creep resistance, so materials for working at high temperature and which having also good creep resistance are a critical issue in manufacturing. this paper present a review about the Ni- base super alloys, which working at high temperature and also having a good machining property and having good creep resistance. Key words: Super alloys, Ni-based super alloys, temperature, corrosion, strengthening. A alloy that exhibits excellent mechanical strength and resistance to creep at high temperature; good surface stability; and corrosion and oxidation resistance I. INTRODUCTION Super alloys developed high temperature strength through solid solution strengthening .The most important strengthening mechanism is through the formation of secondary phase precipitates such as gamma prime and carbides through precipitation strengthening. Super alloys are designed to be used at temperature of 540˚C and higher, typically up to 0.7× their absol ute melting temperature, which may be up to around 1000˚C. At 760˚C most super alloys have yield strength in excess of 500MPa. They are also corrosion resistant. [1] There are three types of super alloys:  Iron nickel based – these are an extension of stainless steel technology and are frequently wrought. Typically contain 20-40% NI, 15-20% CR, 30-50% Fe, plus Mo, Al, Ti.  Nickel based – may be wrought or cast. Typically more than 40%Ni, 10-20%Cr, up to 10%Al, and T, 5-10% Co, and small amount of B, Zr, and C. Mo, W and Nb are also commonly added.  Cobalt based – may be wrought or cast. Typically contain 35-60% Co, 20-30%Cr, up to 35%Ni with some W and Mo. Table 1 Nomenclature II. IMPROVEMENT OF SUPER ALLOYS BY CHEMISTRY CONTROL The production of super alloy components initially requires some sort of melting process. The melting produces ingots which are remelted, converted to powder for subsequent con- solidation to a component, or investment cast. Remelting is used to produce an ingot which can be processed to wrought mill forms (e.g., bar stock) or forged. Until the start of the second half of the twentieth century, melting of super alloys was conducted in air or under slag environments. The properties of modern super alloys derive principally from the presence of many elements which are reactive with oxygen and so were being lost to some or a great degree in the melting and casting process. When vacuum melting techniques were introduced to commercial production of articles, they were pioneered by superalloys. The vacuum en- abled the melting of superalloys containing higher amounts of the hardeners aluminum and titanium. Furthermore, the concurrent reduction in gases, oxides, and other impurities created a significant improvement in the ductility of superalloys. Moreover, with more hardener content, strengths of superalloys began to increase dramatically. [2] III. NI-BASED SUPERALLOYS Nickel-based superalloys are unusual class of metallic materials with an exceptional combination of high temperature strength, toughness and resistance to degradation in corrosive or oxidizing environment. These materials are widely used in aircraft and power generation turbine, rocket engines, and other challenging environment, including nuclear power and chemical processing plants. [3] Nickel based superalloys are the most complex, the most widely used for the hottest part, and too many metallurgists, the most interesting of all superalloys. Nickel based – may be wrought or cast. Typically more than 40%Ni, 10-20%Cr, up to 10%Al, and T, 5-10% Co, and small amount of B, Zr, and C. Mo, W and Nb are also commonly added. IV. CHARACTERISTICS OF NI-BASED SUPERALLOYS Nickel-containing super alloys are selected for use in certain applications due to their characteristics. Among the important characteristics are creep resistance at high temperatures, good surface stability, and corrosion and oxidation resistance. One of their most important properties is high temperature creep resistance. [4] Some other characteristics as follows:-  FCC (γ) austenitic matrices based on Ni.  Solid solution strengthening is through alloy element that partition to γ.  Alloys are also precipitation hardened via intermetallic borides or carbides.  Alloys are also precipitation strengthened by modifying grain boundaries. A listing of some of the super alloys, with information on their composition and some of the uses is provided here:-