Author: Y. OtaPublisher:
ISBN:
Category :
Languages : en
Pages : 28
Book Description
Production and Characterization of Ni-base Superalloy Single Crystals
Author: Y. OtaNickel Base Single Crystals Across Length Scales
Author: Loeïz NazéPublisher: Elsevier
ISBN: 0128193581
Category : Technology & Engineering
Languages : en
Pages : 612
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
Alloy Design and Characterization of γ′ Strengthened Nickel-based Superalloys for Additive Manufacturing
Author: Jinghao XuPublisher: Linköping University Electronic Press
ISBN: 9179297269
Category :
Languages : en
Pages : 63
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.
Determination of Cleavage Planes and Fracture Characterization of Nickel-base Single Crystal Superalloys
Author: John M. MerrillPublisher:
ISBN:
Category : Fracture mechanics
Languages : en
Pages : 140
Book Description
An Analysis of Primary Creep of Nickel-base Superalloy Single Crystals
Author: P. R. PASLAYCharacterisation of the Microstructural Evolution of Single Crystal Nickel-base Superalloys
Author: D. C. CoxCharacterization of Phases in a Nickel Base Superalloy
Author: Shanker, KartikAnalysis and Design of Nickel-based Single Crystal Superalloys
Author: Zailing ZhuNi-Based Superalloys
Author: James CoakleyPublisher: Trans Tech Publications Ltd
ISBN: 3035731616
Category : Technology & Engineering
Languages : en
Pages : 720
Book Description
Aggregated Book
Superalloys
Author: Nataliya V. KazantsevaPublisher: CRC Press
ISBN: 1351603329
Category : Technology & Engineering
Languages : en
Pages : 207
Book Description
Superalloys form a class of the structural materials for high-temperature applications. Nickel superalloys are extensively used in the high-temperature components of gas turbines due to their excellent creep, fatigue, and corrosion resistance at elevated temperatures. These materials are considered paramagnetic in the range of working temperatures. This book presents the features of the ternary phase diagrams Ni-Al-X (X = {Co, Fe, Nb, Ti, Cr}), effects of the alloying on the long-range order and mechanical properties of the Ni3 Al-based alloys. Description of the strain-induced ferromagnetism in the Ni3Al-based alloys and magnetic control of the failure of gas turbine blades are also included. A separate section is devoted to the analysis of the vibration process and strength change in the single-crystal gas turbine blades. This book includes the review of the new intermetallic cobalt superalloys. The structure, crystal lattice parameters, orientation relationships between phases, mechanical and magnetic properties of the Co3(Al,W)-based alloys are described. Non-destructive magnetic point control of the martensite content in low-magnetic austenitic alloys is a new method for detection of the local sites with internal stresses. This method is useful for the detection of the residual stress in the critical parts of industrial products. This book may be useful for specialists in material science, first-year postgraduate students taking a class in material science and engineering, and engineers developing new alloys for the gas turbine technology.