Download or read book Micromechanisms of Low Cycle Fatigue in Nickel Based Superalloys at Elevated Temperatures written by RM. Pelloux and published by . This book was released on 1979 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Elevated Temperature Low Cycle Fatigue of Nickel Base Superalloys in the Conventionally Cast Directionally Solidified and Single Crystal Forms written by Stephen D. Antolovich and published by . This book was released on 1983* with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: High temperature low cycle fatigue (LCF) has been studied for directionally solidified (DS) and conventionally cast (CC) Rene' 80. For the conventionally cast material testing was carried out on smooth bars over the temperature range 75 F (24 C) to 1800 F (982 C). It was found that at low temperatures slip was planar and carbides acted as crack initiation sites. In correspondence with the importance of carbides on the fatigue life it was found that life cosrrelated best with total strain range (as opposed to plastic strain range).
Download or read book High Temperature Low Cycle Fatigue Mechanisms for a Nickel base and a Copper base Alloy written by Chin-I. Shih and published by . This book was released on 1982 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue Mechanisms written by Jeffrey T. Fong and published by ASTM International. This book was released on 1979 with total page 936 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Model for Life Predictions of Nickel Base Superalloys in High Temperature Low Cycle Fatigue written by SD. Antolovich and published by . This book was released on 1988 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extensive characterization of low-cycle fatigue damage mechanisms was performed on polycrystalline René 80 and IN100 tested in the temperature range from 871 to 1000°C. Low-cycle fatigue life was found to be dominated by propagation of microcracks to a critical size governed by the maximum tensile stress. A model was developed which incorporates a threshold stress for crack extension, a stress-based crack growth expression, and a failure criterion. The mathematical equivalence between this mechanistically based model and the strain-life low-cycle fatigue law was demonstrated using cyclic stress-strain relationships. The model was shown to correlate the high-temperature low-cycle fatigue data of the different nickel-base superalloys considered in this study.
Download or read book Microstructural Effects and Fatigue Life Predictions of Notched and Un notched Nickel Base Superalloys at Elevated Temperatures written by Stephen D. Antolovich and published by . This book was released on 1978 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: The low cycle fatigue (LCF) of Rene 80 has been investigated at 1400, 1600 and 1800 F. Emphasis has been placed on the 1800 F studies using smooth bar (continuous cycling and 90 sec hold time) and notch LCF specimens. The detailed transmission electron microscopy shows that at 1600 and 1800 F the dislocation debris is independent of test rate over two orders of magnitude. The test results can not be explained in terms of the conventional approaches to high temperature LCF for which damage is assumed to result from creep/fatigue interactions. Instead, it is suggested that the important damage mechanism is an interaction between the deformation mode and the environment. Based on that understanding a model is developed for crack propagation at elevated temperatures and a similar model is being developed for crack initiation. (Author).
Download or read book Mechanisms of Damage and Fracture in High temperature Low cycle Fatigue of a Cast Nickel base Superalloy written by C. J. MCMAHON and published by . This book was released on 1970 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microstructural Effects and Fatigue Life Predictions of Notched and Un notched Ni Base Superalloys at Elevated Temperatures written by Stephen D. Antolovich and published by . This book was released on 1980 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: The LCF(Low Cycle Fatigue) behavior of Ni base superalloys was studied both for smooth and notched test bars. The primary research material was Rene 80 which finds application in turbine blades used in the temperature range of 650-982 C (1200-1800 F). The smooth bar LCF behavior was studied in the as-heat treated condition and also after exposure for 100h at 982 C, either under a stress of 97 MPa (14 ksi) or OMPa. Test conditions included continuous cycling at different strain rates as well as 90 second hold periods at either maximum or minimum strain. The primary test temperatures were 871 C (1600 F) and 982 C (1800 F). It was found that prior exposure greatly reduces the fatigue life. Since these experiments tend to duplicate actual engine conditions, use of data obtained using as-heat treated specimens may be very non-conservative to predict lives of actual components. The test results correlated very well with a model for LCF which is based on the concept that cracks initiate at a critical combination of oxide depth and stress. The notch LCF problem was also studied. A computer model for calculating local stresses and strains was developed. In addition to the Rene 80 studies, some initial smooth bar LCF studies were carried out using Rene 77.
Download or read book High Temperature Low Cycle Fatigue and Correlation to Crack Growth Rate in Two Nickel Base Superalloys written by Seung Joo Choe and published by . This book was released on 1985 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Temperature Low cycle Fatigue Behaviour of Nickel base Superalloys written by L. Massarelli and published by . This book was released on 1977 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Elevated Temperature Fatigue Creep Behavior of Nickel Base Superalloy IN 625 written by A. Biron and published by . This book was released on 1988 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: A research program has been carried out to establish the low-cycle fatigue and creep-fatigue behaviors of Inconel 625 at elevated temperatures (650 and 815°C). The main observations were related to the effect of temperature and of hold times. Under continuous cycling, a temperature increase from 650 to 815°C caused a reduction in the fatigue life by a factor of 2 at a high strain and by a factor of 3 at a low strain.
Download or read book High Temperature Low Cycle Fatigue Data for Three High Strength Nickel Base Superalloys written by J. B. Conway and published by . This book was released on 1980 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents a summary of the high temperature low cycle fatigue data for three high strength nickel-base superalloys, Rene 95, AF-115, and AF2-1DA. The majority of tests were performed in strain control at 1200 F and 1400 F, and at frequencies of 20 cpm, 0.2 cpm, and 0.05 cpm. Conventional triangular waveform was used for most of the testing although strain dwell tests and some SLOW-FAST and FAST-SLOW tests were also included. (author).
Download or read book Aerospace Structural Metals Handbook written by and published by . This book was released on 1989 with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Superalloys 2012 written by Eric S. Huron and published by John Wiley & Sons. This book was released on 2012-10-02 with total page 952 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Nickel Base Superalloys Rene 95 and Inconel 718 written by Shahid Bashir and published by . This book was released on 1982 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Temperature Low cycle Fatigue Behaviour of Nickel base Superalloys Influence of Testing Frequency and Stree Or Strain Wave Form written by L. Massarelli and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Softening Mechanisms and Microstructural Instabilities of Nickel During High Temperature Low Cycle Fatigue written by Shuhrong Chen and published by . This book was released on 1989 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:
