Download or read book Fatigue Crack Growth Characteristics of Thin Sheet Titanium Alloy Ti 6 2 2 2 2 written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-31 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue crack growth rates of Ti 6-2-2-2-2 as a function of stress ratio, temperature (24 or 177 C), tensile orientation and environment (laboratory air or ultrahigh vacuum) are presented. Fatigue crack growth rates of Ti 6-2-2-2-2 are also compared with two more widely used titanium alloys (Timetal 21S and Ti 6Al-4V). The fatigue crack growth rate (da/dN) of Ti 6-2-2-2-2 in laboratory air is dependent upon stress ratio (R), particularly in the near-threshold and lower-Paris regimes. For low R (less than approximately 0.5), da/dN is influenced by crack closure behavior. At higher R (> 0.5), a maximum stress-intensity factor (K(sub max)) dependence is observed. Fatigue crack growth behavior is affected by test temperature between 24 and 177 C. For moderate to high applied cyclic-stress-intensity factors (delta-K), the slope of the log da/dN versus log delta-K curve is lower in 177 C laboratory air than 24 C laboratory air. The difference in slope results in lower values of da/dN for exposure to 177 C laboratory air compared to room temperature laboratory air. The onset of this temperature effect is dependent upon the applied R. This temperature effect has not been observed in ultrahigh vacuum. Specimen orientation has been shown to affect the slope of the log da/dN versus log delta-K curve in the Paris regime.Smith, Stephen W. and Piascik, Robert S.Langley Research CenterCRACK PROPAGATION; FATIGUE (MATERIALS); TITANIUM ALLOYS; CORROSION; STRESS RATIO; TEMPERATURE EFFECTS; CRACK CLOSURE; STRESS INTENSITY FACTORS
Download or read book Fatigue Crack Growth Characteristics of Thin Sheet Titanium Alloy Ti 6 2 2 2 2 written by and published by . This book was released on 2001 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book FATIGUE CRACK GROWTH CHARACTERISTICS OF THIN SHEET TITANIUM ALLOY TI 6 2 2 2 2 NASA TM 2001 210830 JUN 20 2001 written by 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 Fatigue Crack Growth Thresholds Endurance Limits and Design written by J. C. Newman and published by ASTM International. This book was released on 2000 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation Contains 24 papers from the November, 1998 symposium of the same name, sponsored by the ASTM Committee E8 on Fatigue and Fracture, and presented by Newman and Piascik (both of the NASA Langley Research Center). The papers focus on such areas as fatigue-crack growth threshold mechanisms, loading and specimen-type effects, analyses of fatigue-crack-growth-threshold behavior, and applications of threshold concepts and endurance limits to aerospace and structural materials. Annotation copyrighted by Book News, Inc., Portland, OR.
Download or read book The Effect of O2 H2o and N2 on the Fatigue Crack Growth Behavior of an Alpha Beta Titanium Alloy at 24 C and 177 C written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-17 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: To study the effects of atmospheric species on the fatigue crack growth behavior of an a+B titanium alloy (Ti 6-2-2-2-2) at room temperature and 177 C, fatigue tests were performed in laboratory air, ultrahigh vacuum, and high purity water vapor, oxygen, nitrogen and helium at various partial pressures. Accelerated fatigue crack growth rates in laboratory air compared to ultrahigh vacuum are linked to the damaging effects of both water vapor and oxygen. Observations of the fatigue crack growth behavior in ultrahigh purity environments, along with surface film analysis using X-ray photoelectron spectroscopy (XPS), suggest that multiple crack-tip processes govern the damaging effects of air. Three possible mechanisms are proposed: 1) at low pressure (less than 10(exp -1) Pa), accelerated da/dN is likely due to monolayer adsorption on crack-tip surfaces presumably resulting in decreased bond strengths at the fatigue crack tip, 2) for pressures greater than 10(exp -1) Pa, accelerated da/dN in oxygen may result from oxidation at the crack tip limiting reversible slip, and 3) in water vapor, absorption of atomic hydrogen at the reactive crack tip resulting in process zone embrittlement.Smith, Stephen W. and Piascik, Robert S.Langley Research CenterFATIGUE TESTS; FATIGUE (MATERIALS); CRACK PROPAGATION; TITANIUM ALLOYS; EMBRITTLEMENT; ATMOSPHERIC COMPOSITION; X RAY SPECTROSCOPY; WATER VAPOR; ULTRAHIGH VACUUM; PHOTOELECTRON SPECTROSCOPY
Download or read book Fatigue crack Propagation in Several Titanium and Stainless steel Alloys and One Superalloy written by C. M. Hudson and published by . This book was released on 1964 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of O2 H2O and N2 on the Fatigue Crack Growth Behavior of an alpha beta Titanium Alloy at 24 C Anfd 177 C written by Stephen W. Smith and published by . This book was released on 2001 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: To study the effects of atmospheric species on the fatigue crack growth behavior of an ([alpha]+p titanium alloy (Ti 6-2-2-2-2) at room temperature and 177 °C, fatigue tests were performed in laboratory air, ultrahigh vacuum, and high purity water vapor, oxygen, nitrogen and helium at various partial pressures. Accelerated fatigue crack growth rates in laboratory air compared to ultrahigh vacuum are linked to the damaging effects of both water vapor and oxygen. Observations of the fatigue crack growth behavior in ultrahigh purity environments, along with surface film analysis using X-ray photoelectron spectroscopy (XPS), suggest that multiple crack-tip processes govern the damaging effects of air.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue Crack Propagation Data For Titanium Sheet Alloys No 2 written by R. J. H. Wanhill and published by . This book was released on 1972 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Slip Character and Crack Closure on the Growth of Small Fatigue Cracks in Titanium aluminium Alloys written by James M. Larsen and published by . This book was released on 1990 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation was performed to study the effects of slip character and crack closure on the propagation of small fatigue cracks in titanium- aluminum alloys. The materials examined were solution-treated Ti-4Al and Ti-8Al, as well as aged Ti-8Al. The propagation of naturally initiated surface cracks of depths as small as 25 micrometers was compared with the behavior of large through-thickness cracks. An extensometer was used to monitor crack closure throughout the large crack tests, and the closure behavior of the small cracks was measured using a computerized laser interferometric displacement gage having a displacement resolution of 0.01 micrometer. The measurements of crack closure were used to compute an effective stress intensity factor range. In all three alloys and for all test conditions, which included a range of stress levels and stress ratios, small cracks propagated faster than large cracks subjected to an equivalent Delta K, and the small cracks propagated under conditions that were significantly below the large-crack threshold, Delta K(th). Although the character and distribution of slip in Ti-Al alloys may have a dramatic influence on fatigue crack initiation and on the propagation of large cracks, this effect was minimal for small cracks.
Download or read book NASA Technical Note written by and published by . This book was released on 1965 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Light Weight Alloys for Aerospace Applications IV written by Eui Whee Lee and published by Minerals, Metals, & Materials Society. This book was released on 1997 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a thorough update and review of the various aspects of light weight alloys used for aerospace applications. Discussion topics include alloy development, material processing, microstructure characterization, mechanical behavior, detection and analysis, and applications. Materials covered include conventional aluminum alloys, high-temperature aluminum alloys, aluminum-lithium alloys, titanium alloys, magnesium alloys, beryllium alloys, and metal matrix composites.
Download or read book Fatigue Crack Growth Retardation After Singlecycle Peak Overload in Ti 6a1 4v Titanium Alloy written by Raymond Edward Jones and published by . This book was released on 1972 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue Crack Growth Behavior of Titanium Aluminide Ti 25Al 25Nb written by SJ. Balsone and published by . This book was released on 1993 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fatigue crack growth rate of an orthorhombic + beta titanium aluminide, nominally Ti-25Al-25Nb, was studied as a function of temperature (25 to 750°C), environment (air and vacuum), frequency (0.001 to 1.0 Hz), and superimposed hold times (1 to 1000 s) under computer-controlled constant Kmax testing conditions. In addition, fatigue crack growth rates from the near-threshold region to rates greater than approximately 10-7 m/cycle were determined at room and elevated temperatures. Results show that the fatigue crack growth rate exhibits a combination of cycle- and time-dependent behavior and is sensitive to environment over the entire temperature range. At elevated temperature, crack growth per cycle is found to increase with decreasing frequency in both laboratory air and vacuum, suggesting a contribution from environmentally assisted crack growth. Growth rates in vacuum are as much as an order of magnitude lower than those obtained in air. Further, hold times of increasing duration are found to slightly decrease and then increase the crack growth rate at elevated temperature. At elevated temperatures, crack growth behavior appears to be a complex interaction of environmental degradation at the crack tip, crack-tip blunting due to creep, and cyclic fatigue (resharpening of the crack tip). An attempt was made to correlate the observed fatigue crack growth rates with the mechanism, or mechanisms, of fracture. The crack growth characteristics were compared with those of the alpha-2 titanium aluminide, Ti-24Al-11 Nb, and a conventional high-temperature titanium alloy, Ti-1100.
Download or read book Technical Abstract Bulletin written by Defense Documentation Center (U.S.) and published by . This book was released on 1963 with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
