Download or read book The Effects of Frequency and Waveshape on the Fatigue Crack Growth of an Advanced Nickel Base Superalloy at Elevated Temperatures written by Sara Dalby and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Waveshape on Fatigue Crack Growth in Nickel Superalloys at Elevated Temperature written by Victoria Hodkinson and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Loading Waveform on Fatigue Crack Growth at Elevated Temperature in Nickel Base Superalloys written by S. Dalby and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Materials written by Ivan A. Parinov and published by Springer. This book was released on 2015-12-14 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceedings volume presents selected and peer reviewed 50 reports of the 2015 International Conference on “Physics and Mechanics of New Materials and Their Applications” (Azov, Russia, 19-22 May, 2015), devoted to 100th Anniversary of the Southern Federal University, Russia. The book presents processing techniques, physics, mechanics, and applications of advanced materials. The book is concentrated on some nanostructures, ferroelectric crystals, materials and composites and other materials with specific properties. In this book are presented nanotechnology approaches, modern piezoelectric techniques, physical and mechanical studies of the structure-sensitive properties of the materials. A wide spectrum of mathematical and numerical methods is applied to the solution of different technological, mechanical and physical problems for applications. Great attention is devoted to novel devices with high accuracy, longevity and extended possibilities to work in a large scale of temperatures and pressure ranges, aggressive media, etc. The characteristics of materials and composites with improved properties is shown, and new possibilities in studying of various physico-mechanical processes and phenomena are demonstrated.
Download or read book Cracks in superalloys written by Jonas Saarimäki and published by Linköping University Electronic Press. This book was released on 2018-01-18 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 power supplies are insufficient. New ways of producing greener energy is needed to reduce emission levels. This can be achieved by increasing the combustion temperature of gas turbines. High combustion temperatures can be detrimental and degrade critical components. This raises the demands on the high temperature performance of the superalloys used in gas turbine components. These components are frequently subjected to different cyclic loads combined with for example dwell-times and overloads at elevated temperatures, which can influence the crack growth. Dwell-times have been shown to accelerate crack growth and change cracking behaviour in both Inconel 718, Haynes 282 and Hastelloy X. On the other hand, overloads at the beginning of a dwell-time cycle have been shown to retard the dwell-time effect on crack growth in Inconel 718. More experiments and microstructural investigations are needed to better understand these effects. The work presented in this thesis was conducted under the umbrella of the research program Turbo Power; "High temperature fatigue crack propagation in nickel-based superalloys", where I have mainly looked at fatigue crack growth mechanisms in superalloys subjected to dwell-fatigue, which can have a devastating effect on crack propagation behaviour. Mechanical testing was performed under operation-like cycles in order to achieve representative microstructures and material data for the subsequent microstructural work. Microstructures were investigated using light optical microscopy and scanning electron microscopy (SEM) techniques such as electron channeling contrast imaging (ECCI) and electron backscatter diffraction (EBSD). The outcome of this work has shown that there is a significant increase in crack growth rate when dwell-times are introduced at 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. The crack growth rate decreases with increasing overload levels in Inconel 718 when an overload is applied prior to the dwell-time. At high temperature, intergranular crack growth was observed in Inconel 718 as a result of oxidation and the creation of nanometric voids. Another observed growth mechanism was crack advance along ?-phase boundaries with subsequent oxidation of the ?-phase. This thesis comprises two parts. Part I gives an introduction to the field of superalloys and the acting microstructural mechanisms related to fatigue and crack propagation. Part II consists of five appended papers, which report the work completed as part of the project.
Download or read book Effect of Frequency on Fatigue Crack Growth Rate of Inconel 718 at High Temperature written by and published by . This book was released on 1987 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue crack growth was studied at 650 deg. C as a function of frequency for several ratios of minimum-to-maximum stress intensity, and for two values of maximum stress intensity factor. Crack lengths were monitored at low frequencies from compliance calculations based on crack mouth opening displacement measurements. At higher frequencies, crack length was measured using a d.c. electric potential system. It was found that fatigue crack growth rate can be characterized in three distinct frequency regions. These three regions represent fully cycle dependent, mixed, and fully time dependent crack growth behavior and each region can be modeled by a power law function. Observation of micro mechanisms support the existence of these three different regions of crack growth. Keywords: Fatigue crack growth, Time dependent growth, Cyclic-dependent growth, Nickel base superalloy, Crack growth rate model, Frequency effects.
Download or read book Threshold Crack Growth Behavior of Nickel Base Superalloy at Elevated Temperature written by NE. Ashbaugh and published by . This book was released on 1989 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental program was conducted to evaluate the effects of frequency and R on the near-threshold crack growth behavior of Inconel 718 at 649°C in laboratory air. Frequencies from 0.01 to 400 Hz and R from 0.1 to 0.9 were applied to compact tension [C(T)] and middle- or center-cracked tension [M(T)] specimens under decreasing-K conditions using computer-controlled test machines. Digital load-displacement data were obtained to determine crack length and closure load. The fatigue crack growth threshold in Inconel 718 at 649°C obtained using decreasing ?K testing was generally associated with a crack arrest phenomenon which could be attributed to the buildup of oxides with time. Over the ranges of R and v used in this investigation, the growth rate behavior at the onset of crack arrest appears to be a combination of time-dependent and cyclic-dependent behavior. Even at 400 Hz, purely cyclic behavior was apparently never reached. For crack growth rate modeling, both frequency and stress ratio have to be incorporated in the characterization of ?Kth. Over the ranges of parameters tested, a cyclic threshold was approached at high frequencies and low R and a sustained load time-dependent threshold was obtained at high R, indicating that the cyclic contribution to the growth rate was negligible.
Download or read book Effect of Loading Waveform on Fatigue Crack Growth at Elevated Temperature in Nickel Base Superalloys written by S. Dalby and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dwell Fatigue Crack Growth at Elevated Temperatures in an Advanced Nickel Disc Superalloy written by Suyang Yu and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Influence of Frequency Stress Ratio and Stress State on Fatigue Crack Growth in Nickel Base Superalloys at Elevated Temperature written by Fernando Jorge Ventura Antunes and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Frequency on Fatigue Crack Growth Rate of Inconel 718 at High Temperature written by Tusit Weerasooriya and published by . This book was released on 1987 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue crack growth was studied at 650 deg. C as a function of frequency for several ratios of minimum-to-maximum stress intensity, and for two values of maximum stress intensity factor. Crack lengths were monitored at low frequencies from compliance calculations based on crack mouth opening displacement measurements. At higher frequencies, crack length was measured using a d.c. electric potential system. It was found that fatigue crack growth rate can be characterized in three distinct frequency regions. These three regions represent fully cycle dependent, mixed, and fully time dependent crack growth behavior and each region can be modeled by a power law function. Observation of micro mechanisms support the existence of these three different regions of crack growth. Keywords: Fatigue crack growth, Time dependent growth, Cyclic-dependent growth, Nickel base superalloy, Crack growth rate model, Frequency effects.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1988 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Frattura ed Integrit Strutturale Annals 2014 written by Luca Susmel and published by Gruppo Italiano Frattura. This book was released on 2014-09-12 with total page 1208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Elevated Temperature Fatigue Crack Growth in a Nickel Base Superalloy Under Dwell Conditions written by J. Byrne and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Carburizing Environments on Elevated Temperature Fatigue Crack Growth Behavior in the Nickel base Superalloy Nimonic 115 written by Carl J. White and published by . This book was released on 1981 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Near Threshold Fatigue Crack Growth Behavior of Fine Grain Nickel Based Alloys written by John A. Newman and published by . This book was released on 2003 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Elevated Temperature Pre exposure on the Creep fatigue Crack Growth Behaviour of a Polycrystalline Nickel base Superalloy written by D. W. Hunt and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
