Characterization of a Nickel-base Superalloy Through Electrical Resistivity-microstructure Relationships Facilitated by Small Angle Scattering PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Characterization of a Nickel-base Superalloy Through Electrical Resistivity-microstructure Relationships Facilitated by Small Angle Scattering PDF full book. Access full book title Characterization of a Nickel-base Superalloy Through Electrical Resistivity-microstructure Relationships Facilitated by Small Angle Scattering by Ricky Lee Whelchel. Download full books in PDF and EPUB format.
Author: Ricky Lee Whelchel Publisher: ISBN: Category : Electric resistance Languages : en Pages :
Book Description
Nickel-base superalloys obtain high temperature mechanical properties through formation of precipitate phases formed via heat treatment. The precipitate microstructure evolves with heat treatment or thermal exposure, which can lead to degrading mechanical properties. This project focuses on the use of electrical resistivity as a non-destructive testing method to monitor the precipitate phase in Waspaloy (a polycrystalline nickel-base superalloy). The evolution of the precipitate microstructure is characterized throughout the volume of the specimens using both small angle neutron scattering (SANS) and ultra small angle X-ray scattering (USAXS) measurements. These measurements are also aided by microscopy and X-ray diffraction measurements.
Author: Ricky Lee Whelchel Publisher: ISBN: Category : Electric resistance Languages : en Pages :
Book Description
Nickel-base superalloys obtain high temperature mechanical properties through formation of precipitate phases formed via heat treatment. The precipitate microstructure evolves with heat treatment or thermal exposure, which can lead to degrading mechanical properties. This project focuses on the use of electrical resistivity as a non-destructive testing method to monitor the precipitate phase in Waspaloy (a polycrystalline nickel-base superalloy). The evolution of the precipitate microstructure is characterized throughout the volume of the specimens using both small angle neutron scattering (SANS) and ultra small angle X-ray scattering (USAXS) measurements. These measurements are also aided by microscopy and X-ray diffraction measurements.
Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
This report summarizes the results accomplished during this 3-year with funds from this grant. The most important new contribution was the development of a microstructural model, based on analysis of the small angle scattering spectra that can relate the measured electrical resistivity to the precipitate population present in a nickel base superalloy in a quantitative way. A total of 24 research articles were published or were in press at the time the final report was written.
Author: Jinghao Xu Publisher: 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.
Author: Loeïz Nazé Publisher: 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
Author: Pranaam Haldipur Publisher: ISBN: Category : Languages : en Pages : 312
Book Description
Nickel-based super alloys are widely used in aircraft engine components, mainly in turbine disks and the high-pressure compressor. Extensive data on the mechanical properties of these alloys is available. However, fundamental data relating micro-structural features to ultrasonic properties, in turn controlling the inspectability, are not available. Knowledge of these relationships would facilitate improvements in current Ni billet inspections. A single scattering model has been found to be very effective in simulating the effects of backscattered noise on the ultrasonic inspection of billets and forgings engine alloy materials. The work on this dissertation is focused on evaluating the effectiveness of the single scattering model in predicting backscattered noise in the nickel-based alloys. Attenuation, grain size and single-crystal elastic constants are important input parameters that need to be evaluated for making the predictions of noise levels. Determination of these quantities on a number of nickel-based super alloy samples is reported and studied how noise levels predicted with the current single scattering model compare with the direct measurements of noise on the same samples. In Chapter 1, experimental investigations of the relationships between ultrasonic properties (velocity, attenuation, and backscattered grain noise FOM) and the microstructure are reported. A close relationship was established between the measured attenuation and the Noise FOM, a result consistent with classical theories for backscattering and attenuation but inconsistent to observations in titanium. Chapter 2 describes a quantitative study of the relationship of the experimental observations reported in Chapter 1 to the predictions of classical theories, which require as input the single-crystal elastic constants of the grains and the grain size. The single-crystal elastic constants for these alloys are unknowns and an effort to infer the same for the nickel-based super alloys from ultrasonic measurements is reported. In Chapter 3, a detailed study of the accuracy of the single scattering model to predict the grain noise generated by the microstructure was carried out. Detailed measurements and model calculations were carried out to quantify the breakdown of the single scattering model the comparison of theory and experiment provided strong evidence for the presence of multiple scattering effects.
Author: Daniel Richard Corwin Publisher: ISBN: Category : Heat resistant alloys Languages : en Pages : 224
Book Description
Abstract: I would like to thank Dr. Michael Mills, my adviser, for providing excellent support and guidance throughout this work. I'd also like to thank Eric Payton for his contributions and advice regarding practically all aspects of this project. Close collaboration with Dr. Yunzhi Wang, Gang Wang, and Ning Ma has been a very beneficial experience that has given me a valuable understanding of microstructure modeling. I am also very appreciative of the help received from Peter Sarosi, Libor Kovarik, and Ray Unocic regarding the transmission electron microscopy performed in this research. I wish to thank Dave Mourer, Deb Whitis, and Dan Wei at GE Aviation for providing guidance and direction in addition to making this research opportunity possible. Thanks to Ron Tolbert for helping procure the needed materials. I am grateful for the superior quality of the Campus Electron Optics Facility at OSU, and I'd like to specifically thank Cameron Begg and Henk Colijn for their assistance with SEM and TEM operation. This research was funded by GE Aviation.
Author: RA. MacKay Publisher: ISBN: Category : Creep Languages : en Pages : 20
Book Description
This paper discusses some of the microstructural features which influence the creep properties of directionally solidified and single-crystal nickel-base superalloys. Gamma prime precipitate size and morphology, ?-?' lattice mismatch, phase instability, alloy composition, and processing variations are among the factors considered. Recent experimental results are reviewed and related to the operative deformation mechanisms and to the corresponding mechanical properties. Special emphasis is placed on the creep behavior of single-crystal superalloys at high temperatures, where directional ?' coarsening is prominent, and at lower temperatures, where ?' coarsening rates are significantly reduced. It can be seen that very subtle changes in microstructural features can have profound effects on the subsequent properties of these materials.
Author: Ricky Lee Whelchel
Author: Ricky Lee Whelchel
Author: 
Author: Jinghao Xu
Author: Loeïz Nazé
Author: Pranaam Haldipur
Author: Daniel Richard Corwin
Author: 
Author: David Matthew Collins
Author: RA. MacKay
Author: James Coakley