Download or read book The influence of slip character and microstructure on fatigue crack growth in Alpha and Alpha Beta Titanium alloys written by John E. Allison and published by . This book was released on 1982 with total page 0 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 Influence of Metallurgical Factors on the Fatigue Crack Growth Rate in Alpha Beta Titanium Alloys written by J. C. Chesnutt and published by . This book was released on 1978 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research was conducted on two alpha-beta titanium alloys, Ti-6Al-4V and Ti-6Al-2Sn 4Zr-6Mo, as a function of alloy composition microstructure and strength level, environment, and fatigue loading conditions. A wide range of microstructural conditions, seven for Ti-6Al-4V and three for Ti-6Al-2Sn-4Zr-6Mo, was chosen to provide a full range of constituent types and morphologies and a range of mechanical properties. All the material for the program was obtained in the form of pancake forgings which were uniformly and weakly textured. The initial portion of the program consisted of material characterization and base line fatigue crack propagation (FCP) testing. Characterization included a full description of microstructures, as well as mechanical property testing, fracture toughness tests, S-N curve determination and measurement of other properties such as modulus and texture. Base line FCP testing in dry air at two stress ratios (R) of 0.1 and 0.3; and in a 3.5% NaCl solution at 1 and 20 Hz was conducted in this portion of the program. Results of this study included the determination that transformed beta microstructures generally exhibit the greatest fatigue crack propagation resistance and that increasing the load ration, R, can lead to significant increases in crack growth rate; the behavior in both cases was rationalized in terms of crack tip interaction with microstructural constituents.

Download or read book Fatigue Crack Propagation in Ti Alloys written by and published by . This book was released on 1978 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: The influence of microstructure, slip behavior, and gaseous environment on the fatique crack propagation of Ti alloys has been investigated. Large grain or single crystal material has been used extensively in order to ensure that the crack-tip plasticity is smaller than the scale of the microstructure. As a result, extensive Stage I crack propagation occurs. The experimental relationships between crack-tip plasticity, orientation of the crack plane to the stress axis, fractography, and the resulting fatigue crack growth behavior is presented. Several Ti alloys are examined in lab air, dry helium, or hydrogen environments: beta-phase Ti-40V, metastable beta Ti-27V, and Ti-30V, alpha-phase Ti-4Al, and the alpha-beta alloy, Ti-8Al-1Mo-lV. The behavior of the beta Ti alloys can be analyzed primarily in terms of crack advance by an intersecting slip process resulting from flow on at least two active slip systems. In contrast, the mechanism for Stage I fatigue in alpha and alpha + beta Ti alloys appears to be dominated by basal slip and strongly influenced by environment. Aspects of the cyclic stress-strain behavior of beta and alpha + beta Ti alloys are also reported. In addition, strengthening of Ti alloys by eutectoid decomposition is briefly discussed. (Author).

Download or read book Fatigue of Beta Processed and Beta Heat treated Titanium Alloys written by Russell Wanhill and published by Springer Science & Business Media. This book was released on 2011-10-28 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication reviews most of the available literature on the fatigue properties of β annealed Ti-6Al-4V and titanium alloys with similar microstructures. The focus is on β processed and β heat-treated alloys because β annealed Ti-6Al-4V has been selected for highly loaded and fatigue-critical structures, including the main wing-carry-through bulkheads and vertical tail stubs, of advanced high-performance military aircraft. An important aspect of the review is a concise survey of fatigue life assessment methods and the required types of fatigue data. This survey provides the background to recommendations for further research, especially on the fatigue behaviour of β annealed Ti-6Al-4V under realistic fatigue load histories, including the essential topic of short/small fatigue crack growth. Such research is required for independent fatigue life assessments that conform to the aircraft manufacturer’s design requirements, and also for life reassessments that most probably will have to be made during the service life of the aircraft.

Download or read book Mechanics of Fatigue Crack Closure written by Wolf Elber and published by ASTM International. This book was released on 1988 with total page 671 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 and 177 C written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-11 with total page 32 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 Metals Abstracts written by and published by . This book was released on 1983 with total page 1058 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Microstructure on Fatigue Behavior of Titanium Alloys written by Vikas Sinha and published by . This book was released on 2000 with total page 284 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 1993 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Crack Propagation in Ti Mn Alloys The Role of the Bauschinger Effect written by H. Margolin and published by . This book was released on 1983 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work on this program consisted of three parts: study of fatigue crack propagation behavior of alpha-beta Ti-Mn alloys; rationalization of the role of microstructure in the fracture toughness of the alpha-beta alloy Ti-5.25Al-5.5V-0.9//Fe-0.5Cu; and n examination of slip transfer from alpha - beta. A summary of the achievements in each of these areas and pertinent additional information will be given in the following presentation.

Download or read book Observations on the Generality of the Grain Size Effect on Fatigue Crack Growth in Alpha Plus Beta Titanium Alloys written by G. R. Yoder and published by . This book was released on 1980 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results obtained through analysis of the literature agree with those of our own as regards the effect of grain size (l) on region-II fatigue crack growth rates (da/dN) of alpha + beta titanium alloys in ambient air, viz. that for a given value of stress-intensity range (delta kappa), da/dN decreases as (l) is increased. The analysis indicates that when microstructural modification of a given alloy affects a reduction in da/dN, the reduction appears attributable to an increase in (l); conversely, when microstructural modification fails to affect a significant change in da/dN, the result appears attributable to a negligible change in (l). Comparison of fatigue crack growth behavior at stress-intensity ranges of 15, 21 and 40 MPa square root m indicates a diminution of the grain-size effect with increased delta kappa. As elucidated in terms of the reversed plastic zone size model, diminution of the grain-size effect follows as a consequence of the reduced portion of the structure-sensitive mode of crack growth present as delta kappa is increased.

Download or read book Influence of Alpha Beta Interface Phase on Fracture Toughness and Fatigue Crack Growth Rate in Ti 6Al 4V written by C. G. Rhodes and published by . This book was released on 1980 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: The alpha/beta interface phase is a microstructural feature which occurs in two-phase, alpha/beta, titanium alloys under certain processing conditions. Interface phase can grow to widths of up to approx. 500 nm and has been shown to exert an influence on tensile properties. In this work, its influence on fracture toughness and fatigue crack growth rate in Ti-6Al-4V has been examined. (Author).

Download or read book Proceedings of the 13th World Conference on Titanium written by Vasisht Venkatesh and published by John Wiley & Sons. This book was released on 2016-04-26 with total page 2004 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the Proceedings of the 13th World Conference on Titanium.

Download or read book The effect of slip character and crack closure on the growth of small fatigue cracks in titanium aluminum alloys written by James Larsen and published by . This book was released on 1989 with total page 0 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 aluminum Alloys written by James Milligan Larsen and published by . This book was released on 1987 with total page 261 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Structural Materials written by Winston O. Soboyejo and published by CRC Press. This book was released on 2006-12-21 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: A snapshot of the central ideas used to control fracture properties of engineered structural metallic materials, Advanced Structural Materials: Properties, Design Optimization, and Applications illustrates the critical role that advanced structural metallic materials play in aerospace, biomedical, automotive, sporting goods, and other indust