Fatigue Crack Initiation And The Growth Of Short Cracks In Nickel Based Superalloys
DOWNLOAD
Download Fatigue Crack Initiation And The Growth Of Short Cracks In Nickel Based Superalloys PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Fatigue Crack Initiation And The Growth Of Short Cracks In Nickel Based Superalloys book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page
Fatigue Crack Initiation And The Growth Of Short Cracks In Nickel Based Superalloys
DOWNLOAD
Author : James Finis McCarver
language : en
Publisher:
Release Date : 1981
Fatigue Crack Initiation And The Growth Of Short Cracks In Nickel Based Superalloys written by James Finis McCarver and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1981 with Chromium-cobalt-nickel-molybdenum alloys categories.
A Study Of The Fatigue Behavior Of Short Cracks In Nickel Based Superalloys
DOWNLOAD
Author : R. M. Pelloux
language : en
Publisher:
Release Date : 1985
A Study Of The Fatigue Behavior Of Short Cracks In Nickel Based Superalloys written by R. M. Pelloux and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1985 with categories.
Fatigue behavior of short cracks was studied in Inconel X-750, Inconel 718, Waspaloy and PM-Rene 95. Crack growth rates were measured for crack lengths from 50 microns to 2mm. Three regimes of behavior were generally observed: 1) an initiation regime in which crack propagation rates are nearly zero; 2) a short crack regime in which crack propagation rates increase slowly and variably with crack length but with propagation rates higher than would be predicted by LEFM in the near-threshold regime; and 3) a long crack regime in which conventional fracture mechanics is applicable. The threshold criterion and crack propagation rates for short cracks are shown to be strongly dependent on the stress ratio. Negative stress ratios promotes rapid crack initiation. This behavior is confirmed theoretically by a Dugdale model which establishes a criterion for crack extension based on the accumulation of plastic work in the crack tip plastic zone. Fractographic investigations show that short cracks propagate in a transgranular-crystallographic mode following a zig-zag path which is macroscopically perpendicular to the applied stress. An experimental technique was developed to generate small eliptical crack initiation sites using a pulsed Nd-YAG laser. An AC potential drop system for continuous and automated measurements of crack length at elevated temperature has been assembled.
Fatigue Crack Initiation And The Growth Of Short Cracks In Nickel Based Superalloys
DOWNLOAD
Author : James Finis McCarver
language : en
Publisher:
Release Date : 1981
Fatigue Crack Initiation And The Growth Of Short Cracks In Nickel Based Superalloys written by James Finis McCarver and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1981 with Nickel alloys categories.
A Study Of The Fatigue Behavior Of Small Cracks In Nickel Base Superalloys
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 1988
A Study Of The Fatigue Behavior Of Small Cracks In Nickel Base Superalloys written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1988 with categories.
The fatigue of behavior of short cracks was investigate in five wrought nickel-base superalloys currently used for aircraft turbine disks. Cracks were initiated at artificial defects and at persistent slip bands. Test frequencies ranged from 20Hz to 10cpm. Fatigue crack growth rates were measured over crack lengths ranging from 10 um to 1mm. Most of the testing was performed in load control with stress ranges approaching the cyclic yield strengths of alloys. Strain controlled tests were performed on IN100 under elastic-plastic cycling conditions. Keywords: Crack propagation; Physical metallurgy.
Effect Of Dwell Times On Crack Propagation In Superalloys
DOWNLOAD
Author : Jonas Saarimäki
language : en
Publisher: Linköping University Electronic Press
Release Date : 2015-12-10
Effect Of Dwell Times On Crack Propagation In Superalloys written by Jonas Saarimäki and has been published by Linköping University Electronic Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015-12-10 with categories.
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.
Short Fatigue Crack Growth In A Nickel Base Superalloy At Room And Elevated Temperature
DOWNLOAD
Author : J. C. Healy
language : en
Publisher:
Release Date : 1990
Short Fatigue Crack Growth In A Nickel Base Superalloy At Room And Elevated Temperature written by J. C. Healy and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1990 with Materials categories.
Superalloys 2012
DOWNLOAD
Author : Eric S. Huron
language : en
Publisher: John Wiley & Sons
Release Date : 2012-10-02
Superalloys 2012 written by Eric S. Huron and has been published by John Wiley & Sons this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012-10-02 with Technology & Engineering categories.
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.
Advances In Engineering Materials Structures And Systems Innovations Mechanics And Applications
DOWNLOAD
Author : Alphose Zingoni
language : en
Publisher: CRC Press
Release Date : 2019-08-21
Advances In Engineering Materials Structures And Systems Innovations Mechanics And Applications written by Alphose Zingoni and has been published by CRC Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2019-08-21 with Technology & Engineering categories.
Advances in Engineering Materials, Structures and Systems: Innovations, Mechanics and Applications comprises 411 papers that were presented at SEMC 2019, the Seventh International Conference on Structural Engineering, Mechanics and Computation, held in Cape Town, South Africa, from 2 to 4 September 2019. The subject matter reflects the broad scope of SEMC conferences, and covers a wide variety of engineering materials (both traditional and innovative) and many types of structures. The many topics featured in these Proceedings can be classified into six broad categories that deal with: (i) the mechanics of materials and fluids (elasticity, plasticity, flow through porous media, fluid dynamics, fracture, fatigue, damage, delamination, corrosion, bond, creep, shrinkage, etc); (ii) the mechanics of structures and systems (structural dynamics, vibration, seismic response, soil-structure interaction, fluid-structure interaction, response to blast and impact, response to fire, structural stability, buckling, collapse behaviour); (iii) the numerical modelling and experimental testing of materials and structures (numerical methods, simulation techniques, multi-scale modelling, computational modelling, laboratory testing, field testing, experimental measurements); (iv) innovations and special structures (nanostructures, adaptive structures, smart structures, composite structures, bio-inspired structures, shell structures, membranes, space structures, lightweight structures, long-span structures, tall buildings, wind turbines, etc); (v) design in traditional engineering materials (steel, concrete, steel-concrete composite, aluminium, masonry, timber, glass); (vi) the process of structural engineering (conceptualisation, planning, analysis, design, optimization, construction, assembly, manufacture, testing, maintenance, monitoring, assessment, repair, strengthening, retrofitting, decommissioning). The SEMC 2019 Proceedings will be of interest to civil, structural, mechanical, marine and aerospace engineers. Researchers, developers, practitioners and academics in these disciplines will find them useful. Two versions of the papers are available. Short versions, intended to be concise but self-contained summaries of the full papers, are in this printed book. The full versions of the papers are in the e-book.
Nasa Technical Memorandum
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 1988
Nasa Technical Memorandum written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1988 with Aeronautics categories.
Micromechanisms Of Low Cycle Fatigue In Nickel Based Superalloys At Elevated Temperatures
DOWNLOAD
Author : RM. Pelloux
language : en
Publisher:
Release Date : 1979
Micromechanisms Of Low Cycle Fatigue In Nickel Based Superalloys At Elevated Temperatures written by RM. Pelloux and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1979 with Elevated-temperature fatigue categories.
The micromechanisms of high-temperature fatigue crack initiation and crack propagation in solid-solution and precipitation-strengthened nickel-base super-alloys are reviewed. The marked decrease in fatigue strength of a given superalloy with increasing temperature cannot be solely correlated with the temperature dependence of the short-time mechanical properties. The interactions between oxidation rates and fatigue strengths are very complex. The air environment plays a large role in accelerating the initiation and propagation of fatigue cracks at elevated temperatures. Increasing temperature and decreasing frequency lead to a transition from transgranular to intergranular fracture path.