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Applications in Materials Design
Published in Nirupam Chakraborti, Data-Driven Evolutionary Modeling in Materials Technology, 2023
Superalloys are multi-component alloys (Akca and Gürsel, 2015; Midhani, 2021) exhibiting very high mechanical strength and creep resistance at elevated temperatures. In addition, their properties also include good surface stability, as well as excellent corrosion and oxidation resistance even when used in extreme environments at high temperatures. Owing to these features, superalloys are widely used in chemical and petrochemical plants, power plants, aircraft engine manufacturing, as well as in the oil and gas industries. Superalloys can be Ni-based, Co-based, or Fe-based. They often contain ten or even more alloying elements. Cr, Al, Ti, Mo, W, Ta, and Co are typical alloying elements.
Evolution and Adoption of Microwave Claddings in Modern Engineering Applications
Published in Amit Bansal, Hitesh Vasudev, Advances in Microwave Processing for Engineering Materials, 2023
Dinesh Kumar, Rahul Yadav, Jashanpreet Singh
Superalloys are universally used in extreme conditions such as high-temperature oxidation, fatigue, creep, elevated temperatures, and wear. In recent times, the Ni-based alloys have replaced the Ti alloys in the manufacturing of aircraft gas turbine components. Figure 8.10 represents the various alloys used in the manufacturing of different components of aircraft engines [35]. During the combustion process, there is a high risk involved in the corrosion and wear of these superalloys at extremely higher temperatures. Commercially used powder alloys are (Inconel 100 and 718), Astroloy, Rene (41, 88DT and Rene 95), Nimonic (80A and 105), Waspaloy, Hastelloy (X and S), ATI-718 Plus, Udimet (500 and 700), N18, and AM1 [36, 37]. N18 and AM1 superalloys are used in modern Rafale aircraft engines. However, the novel yttria-stabilized-Zirconia (YSZ) coatings are widely adopted by the aircraft industry [35]. YSZ coatings are beneficial and light in weight; therefore, these coating improves fuel efficiency and reduce noise. However, YSZ coating can be improved by the addition of more ceramics [38]. In this context, thermal barrier coatings (TBCs) can be substituted by further thermal barrier claddings also due to the pore-free layers.
Linear Friction Welding of Ni-Co-Cr Superalloy for Blisk Assembly
Published in Samson Jerold Samuel Chelladurai, Suresh Mayilswamy, Arun Seeralan Balakrishnan, S. Gnanasekaran, Green Materials and Advanced Manufacturing Technology, 2020
P. Sivaraj, D. Manikandan, Vijay Petley, Shweta Verma, V. Balasubramanian
Superalloys were, and continue to be, developed for elevated temperature service. They are utilized at a higher proportion of their actual melting point than any other class of broadly commercial metallic material. They are divided into three classes, namely nickel-based superalloys, cobalt-base superalloys and iron-base superalloys. Superalloys have found applications in aircraft, marine and industrial gas turbines, as well as in rocket engines, nuclear reactors and petrochemical equipment (Ma et al. 2016).
Addition of Co in Ni(Cr)-based cast superalloys for tantalum carbide stabilisation: consequences on the behaviour in oxidation at elevated temperatures
Published in Canadian Metallurgical Quarterly, 2021
Patrice Berthod, Jean-Paul Gomis
Superalloys generally contain aluminium, chromium and/or silicon in high quantities to resist against hot oxidation by more or less complex gaseous mixtures and/or hot corrosion by molten substances. When these two types of attacks on chemicals may co-exist, the alloys must contain preferentially high contents in chromium, such as 20 to 35 wt-%Cr [18,19], since the formed chromia protect alloys from oxidation by gases and corrosion by melts. Chromium being a rather carbide-former element, it can be more or less easy to obtain only TaC carbides. Rather recent studies demonstrated that, despite 30 wt-%Cr for oxidation and corrosion resistance purposes, TaC could easily stay the single carbide in Co-based [20,21] and Fe-based [22] alloys. This is different for Ni-based alloys since chromium carbides (Cr7C3) remain stable and co-exist with TaC carbides [23], due to a 50°C-decrease in refractoriness in {matrix, Cr7C3}-eutectic areas. If the consequences on the oxidation and corrosion behaviours are not harmful (dissolution of the chromium carbide for feeding in Cr the oxidation front), the mechanical properties at elevated temperature may be threatened by these weakened zones in bulk, especially if the expected temperature of service is as high as 1200°C.
Assessing the performance of STED process for fabricating high aspect ratio holes on Inconel 718 alloy
Published in Materials and Manufacturing Processes, 2021
Anuj Vats, Akshay Dvivedi, Pradeep Kumar
To meet the ever-growing need for higher operational efficiency; high-strength materials, commonly referred to as superalloys, are gaining popularity in numerous engineering applications, such as gas turbines and engines, where higher toughness, as well as higher resistance to corrosion, are required at elevated temperatures. In such applications, the structure needs to be cooled, and for this objective, holes, which can enhance the cooling, are incorporated for maintaining the material’s temperature within their metallurgical limits. These holes are also called cooling holes. However, fabrication of cooling holes with a high aspect ratio (AR), in such materials is a daunting challenge because of the low thermal conductivity, high hot hardness, machining chatter, and burr formation issues pertinent to conventional “contact-based” machining processes.[1,2] This is why unconventional “contact-less” machining (Non-Traditional Machining (NTM)) processes like electric discharge machining (EDM), electrochemical machining (ECM), etc. with their variants have emerged as the preferred choices.[3–5] The shaped-tube electrolytic drilling (STED) process, a process variant of ECM from the category of NTM processes, is developed explicitly for manufacturing high AR cooling holes in the turbine blades.[6]
Effect of Zr concentration on the mechanical and thermodynamic properties of NbIr3 intermetallic compounds from theoretical estimations
Published in Philosophical Magazine, 2020
Shi Shu, Lu Yang, Yongzhong Zhan
Superalloy is a kind of long-term high-temperature metal material with high alloying degree. Because of their superior stability and mechanical properties, they are widely used in aviation, aerospace, petroleum, chemical industry, ships and other fields. Platinum group precious metal alloys play a significant role in superalloys [1,2]. Similarly, Ir-based refractory superalloys are widely considered as potential high-temperature structural materials due to their high melting-point, high strength and excellent thermal stability [3–9]. Among those materials, the Ir–Nb intermetallics have attracted widespread academic attention [10,11]. It is worth noting that the structure, mechanical properties and electronic structure of Nb3Ir have been investigated comprehensively [12–14]. Simultaneously, among Ir–Nb intermetallics, it is also noticed that NbIr3 has the largest bulk modulus B, shear modulus G and the lowest percentage anisotropy with high melting points at high-temperature environment [15]. Therefore, cubic L12 intermetallic compounds Ir3Nb is proposed as refractory superalloys [16–19].