Elevated Temperature Fatigue Crack Growth in a Nickel Base Superalloy Under Dwell Conditions

Elevated Temperature Fatigue Crack Growth in a Nickel Base Superalloy Under Dwell Conditions PDF Author: J. Byrne
Publisher:
ISBN:
Category : Materials
Languages : en
Pages :

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Elevated Temperature Fatigue Crack Growth in a Nickel Base Superalloy Under Dwell Conditions

Elevated Temperature Fatigue Crack Growth in a Nickel Base Superalloy Under Dwell Conditions PDF Author: J. Byrne
Publisher:
ISBN:
Category : Materials
Languages : en
Pages :

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Effect of Dwell-times on Crack Propagation in Superalloys

Effect of Dwell-times on Crack Propagation in Superalloys PDF Author: Jonas Saarimäki
Publisher: Linköping University Electronic Press
ISBN: 9176858715
Category :
Languages : en
Pages : 49

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Gas turbines are widely used in industry for power generation and as a power source at "hard to reach" locations where other possibilities for electrical supply are insufficient. There is a strong need for greener energy, considering the effect that pollution has had on global warming, and we need to come up with ways of producing cleaner electricity. A way to achieve this is by increasing the combustion temperature in gas turbines. This increases the demand on the high temperature performance of the materials used e.g. superalloys in the turbine. These high combustion temperatures can lead to detrimental degradation of critical components. These components are commonly subjected to cyclic loading of different types e.g. combined with dwell-times and overloads at elevated temperatures, which influence the crack growth. Dwell-times have shown to accelerate crack growth and change the cracking behaviour in both Inconel 718 and Haynes 282. Overloads at the beginning of the dwell-time cycle have shown to retard the dwell time effect on crack growth in Inconel 718. To understand these effects more microstructural investigations are needed. The work presented in this licentiate thesis was conducted under the umbrella of the research program Turbo Power; "High temperature fatigue crack propagation in nickel-based superalloys", concentrating on fatigue crack growth mechanisms in superalloys during dwell-times, which have shown to have a devastating effect on the crack propagation behaviour. Mechanical testing was performed under operation-like conditions in order to achieve representative microstructures and material data for the subsequent microstructural work. The microstructures were microscopically investigated in a scanning electron microscope (SEM) using electron channeling contrast imaging (ECCI) as well as using light optical microscopy. The outcome of this work has shown that there is a significant increase in crack growth rate when dwell-times are introduced at the maximum load (0% overload) in the fatigue cycle. With the introduction of a dwell-time there is also a shift from transgranular to intergranular crack growth for both Inconel 718 and Haynes 282. When an overload is applied prior to the dwell-time, the crack growth rate decreases with increasing overload levels in Inconel 718. At high temperature crack growth in Inconel 718 took place as intergranular crack growth along grain boundaries due to oxidation and the creation of nanometric voids. Another observed growth mechanism was crack advance along phase boundaries with subsequent severe oxidation of the phase. This thesis comprises two parts. The first giving an introduction to the field of superalloys and the acting microstructural mechanisms that influence fatigue during dwell times. The second part consists of two appended papers, which report the work completed so far in the project.

High Temperature Fatigue Crack Growth in a Ni-based Superalloy

High Temperature Fatigue Crack Growth in a Ni-based Superalloy PDF Author:
Publisher:
ISBN: 9789175190341
Category : Electronic books
Languages : en
Pages : 51

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Dwell Fatigue Crack Growth at Elevated Temperatures in an Advanced Nickel Disc Superalloy

Dwell Fatigue Crack Growth at Elevated Temperatures in an Advanced Nickel Disc Superalloy PDF Author: Suyang Yu
Publisher:
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Category :
Languages : en
Pages :

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High Temperature Fatigue Crack Growth Behavior of Alloy 10

High Temperature Fatigue Crack Growth Behavior of Alloy 10 PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 22

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Mechanical Behaviour of Materials - VI

Mechanical Behaviour of Materials - VI PDF Author: M. Jono
Publisher: Elsevier
ISBN: 1483294137
Category : Technology & Engineering
Languages : en
Pages : 3510

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Book Description
Significant progress in the science and technology of the mechanical behaviour of materials has been made in recent years. The greatest strides forward have occurred in the field of advanced materials with high performance, such as ceramics, composite materials, and intermetallic compounds. The Sixth International Conference on Mechanical Behaviour of Materials (ICM-6), taking place in Kyoto, Japan, 29 July - 2 August 1991 addressed these issues. In commemorating the fortieth anniversary of the Japan Society of Materials Science, organised by the Foundation for Advancement of International Science and supported by the Science Council of Japan, the information provided in these proceedings reflects the international nature of the meeting. It provides a valuable account of recent developments and problems in the field of mechanical behaviour of materials.

Short Fatigue Crack Growth in a Nickel-base Superalloy at Room and Elevated Temperature

Short Fatigue Crack Growth in a Nickel-base Superalloy at Room and Elevated Temperature PDF Author: J. C. Healy
Publisher:
ISBN:
Category : Materials
Languages : en
Pages :

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Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 480

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Fatigue under Thermal and Mechanical Loading: Mechanisms, Mechanics and Modelling

Fatigue under Thermal and Mechanical Loading: Mechanisms, Mechanics and Modelling PDF Author: J. Bressers
Publisher: Springer Science & Business Media
ISBN: 9401586365
Category : Technology & Engineering
Languages : en
Pages : 497

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Book Description
The International Symposium "Fatigue under Thermal and Mechanical Loading", held at Petten (The Netherlands) on May 22-24, 1995, was jointly organized by the Institute for Advanced Materials of The Joint Research Centre, E. C. , and by the Societe Fran~se de Metallurgie et de Materiaux. The fast heating and cooling cycles experienced by many high temperature components cause thermally induced stresses, which often operate in combination with mechanical loads. The resulting thermal / mechanical fatigue cycle leads to material degradation mechanisms and failure modes typical of service cycles. The growing awareness that the synergism between the combined thermal and mechanical loads can not be reproduced by means of isothermal tests, has resulted in an increasing interest in thermal and thermo-mechanical fatigue testing. This trend has been reinforced by the constant pull by industry for more performant, yet safer high temperature systems, pushing the materials to the limit of their properties. Dedicated ASTM meetings in particular have set the scene for this area of research. The proceedings of the symposium organized by D. A. Spera and D. F. Mowbray in 1975 provided a reference book on thermal fatigue which reflects the knowledge and experimental capabilities of the mid-seventies.

Superalloys 2012

Superalloys 2012 PDF 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.