A Study of Deformation and Fatigue in Model Ni-base Superalloys PDF Download

Author: Arnaud De Bussac
Publisher:
ISBN:
Category : Heat resistant alloys
Languages : en
Pages : 156

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Author: Amit Shyam
Publisher:
ISBN:
Category :
Languages : en
Pages : 668

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Author: Eric S. Huron
Publisher: John Wiley & Sons
ISBN: 1118516400
Category : Technology & Engineering
Languages : en
Pages : 952

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Book Description
A superalloy, or high-performance alloy, is an alloy that exhibits excellent mechanical strength at high temperatures. Superalloy development has been driven primarily by the aerospace and power industries. This compilation of papers from the Twelfth International Symposium on Superalloys, held from September 9-13, 2012, offers the most recent technical information on this class of materials.

Author: Jinghao Xu
Publisher: Linköping University Electronic Press
ISBN: 9179297269
Category :
Languages : en
Pages : 63

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Book Description
Nickel-based superalloys, an alloy system bases on nickel as the matrix element with the addition of up to 10 more alloying elements including chromium, aluminum, cobalt, tungsten, molybdenum, titanium, and so on. Through the development and improvement of nickel-based superalloys in the past century, they are well proved to show excellent performance at the elevated service temperature. Owing to the combination of extraordinary high-temperature mechanical properties, such as monotonic and cyclic deformation resistance, fatigue crack propagation resistance; and high-temperature chemical properties, such as corrosion and oxidation resistance, phase stability, nickel-based superalloys are widely used in the critical hot-section components in aerospace and energy generation industries. The success of nickel-based superalloy systems attributes to both the well-tailored microstructures with the assistance of carefully doped alloying elements, and the intently developed manufacturing processes. The microstructure of the modern nickel-based superalloys consists of a two-phase configuration: the intermetallic precipitates (Ni,Co)3(Al,Ti,Ta) known as γ′ phase dispersed into the austenite γ matrix, which is firstly introduced in the 1940s. The recently developed additive manufacturing (AM) techniques, acting as the disruptive manufacturing process, offers a new avenue for producing the nickel-based superalloy components with complicated geometries. However, γ′ strengthened nickel-based superalloys always suffer from the micro-cracking during the AM process, which is barely eliminated by the process optimization. On this basis, the new compositions of γ′ strengthened nickel-based superalloy adapted to the AM process are of great interest and significance. This study sought to design novel γ′ strengthened nickel-based superalloys readily for AM process with limited cracking susceptibility, based on the understanding of the cracking mechanisms. A two-parameter model is developed to predict the additive manufacturability for any given composition of a nickel-based superalloy. One materials index is derived from the comparison of the deformation-resistant capacity between dendritic and interdendritic regions, while another index is derived from the difference of heat resistant capacity of these two spaces. By plotting the additive manufacturability diagram, the superalloys family can be categorized into the easy-to-weld, fairly-weldable, and non-weldable regime with the good agreement of the existed knowledge. To design a novel superalloy, a Cr-Co-Mo-W-Al-Ti-Ta-Nb-Fe-Ni alloy family is proposed containing 921,600 composition recipes in total. Through the examination of additive manufacturability, undesired phase formation propensity, and the precipitation fraction, one composition of superalloy, MAD542, out of the 921,600 candidates is selected. Validation of additive manufacturability of MAD542 is carried out by laser powder bed fusion (LPBF). By optimizing the LPBF process parameters, the crack-free MAD542 part is achieved. In addition, the MAD542 superalloy shows great resistance to the post-processing treatment-induced cracking. During the post-processing treatment, extensive annealing twins are promoted to achieve the recrystallization microstructure, ensuring the rapid reduction of stored energy. After ageing treatment, up to 60-65% volume fraction of γ′ precipitates are developed, indicating the huge potential of γ′ formation. Examined by the high-temperature slow strain rate tensile and constant loading creep testing, the MAD542 superalloy shows superior strength than the LPBF processed and hot isostatic pressed plus heat-treated IN738LC superalloy. While the low ductility of MAD542 is existed, which is expected to be improved by modifying the post-processing treatment scenarios and by the adjusting building direction in the following stages of the Ph.D. research. MAD542 superalloy so far shows both good additive manufacturability and mechanical potentials. Additionally, the results in this study will contribute to a novel paradigm for alloy design and encourage more γ′-strengthened nickel-based superalloys tailored for AM processes in the future.

Author: Roger C. Reed
Publisher: Cambridge University Press
ISBN: 1139458639
Category : Technology & Engineering
Languages : en
Pages : 363

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Book Description
Superalloys are unique high-temperature materials used in gas turbine engines, which display excellent resistance to mechanical and chemical degradation. This book introduces the metallurgical principles which have guided their development. Suitable for graduate students and researchers, it includes exercises and additional resources at www.cambridge.org/9780521859042.

Author: R. W. Neu
Publisher:
ISBN:
Category : Continuum mechanics
Languages : en
Pages : 17

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Crystal viscoplasticity enables one to correctly capture the anisotropic inelastic behavior of single crystal and directionally solidified alloys as well as the microstructural sensitivity in polycrystalline alloys. This paper reviews several physics-based crystal viscoplasticity models that have been established to predict the deformation response of Ni-base superalloys. The attributes of crystal viscoplasticity models necessary for predicting the creep-fatigue deformation are identified. Several new developments in constitutive modeling of Ni-base superalloys are discussed.

Author: C. Laird
Publisher:
ISBN:
Category :
Languages : en
Pages : 18

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Book Description
A report is provided of progress in studying cyclic deformation of precipitation-hardened alloy in a project supported by the army. This work concentrated on the stability of precipitates under cyclic deformation (Al-Ag, Al-Cu systems) and the strain-localization behavior of alloys containing shearable precipitates (Al-Cu, 0'') and non-shearable precipitates (Al-Cu, 0'). Furthermore, the relationship of cyclic response in such simple systems to that of commercial alloy was also studied. The main results are reported.

Author: Loeïz Nazé
Publisher: Elsevier
ISBN: 0128193581
Category : Technology & Engineering
Languages : en
Pages : 612

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Book Description
Nickel Base Single Crystals Across Length Scales is addresses the most advanced knowledge in metallurgy and computational mechanics and how they are applied to superalloys used as bare materials or with a thermal barrier coating system. Joining both aspects, the book helps readers understand the mechanisms driving properties and their evolution from fundamental to application level. These guidelines are helpful for students and researchers who wish to understand issues and solutions, optimize materials, and model them in a cross-check analysis, from the atomistic to component scale. The book is useful for students and engineers as it explores processing, characterization and design. Provides an up-to-date overview on the field of superalloys Covers the relationship between microstructural evolution and mechanical behavior at high temperatures Discusses both basic and advanced modeling and characterization techniques Includes case studies that illustrate the application of techniques presented in the book

Author: James Coakley
Publisher: Trans Tech Publications Ltd
ISBN: 3035731616
Category : Technology & Engineering
Languages : en
Pages : 720

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Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 492

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