Download or read book Understanding the Slip Deformation and Crack Initiation Mechanism in a Near alpha Titanium Alloy During Fatigue Loading written by Conghui Liu and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 The Relationship Between Plastic Deformation and Fracture in Alpha Titanium written by M. F. Amateau and published by . This book was released on 1966 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crack initiation and propagation behavior was studied in unalloyed titanium containing between 0.25 and 0.6% oxygen and in Ti-5Al-2.5Sn alloy containing between 0.07 and 0.37% oxygen. Large-grained tensile specimens were tested at -320 F and metallographically examined to identify the mechanism of microcrack formation. Precracked single edge notched specimens were tested at -320 F in order to relate crack propagation events to fracture energy and grain orientation. Second order twin induced microcracking, which is responsible for brittle behavior in unalloyed titanium at 0.25% oxygen, becomes restricted at 0.5 and 0.6% oxygen. In Ti-5Al-2.5Sn alloy containing 0.3% oxygen, slip induced microcracks form in addition to twin induced microcracks. A general correlation was found between fracture energy, grain orientation and crack propagation events in unalloyed titanium containing 0.25 to 0.6% oxygen. (Author).
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 4024 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 Cyclic Stress Strain and Plastic Deformation Aspects of Fatigue Crack Growth written by L. F. Impellizzeri and published by ASTM International. This book was released on 1977 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Creep Fatigue and Deformation of Alpha and Alpha beta Titanium Alloys at Ambient Temperature written by Matt C. Brandes and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Titanium and it alloys are extensively utilized in critical applications that require materials with high strength to weight ratios, rigidities, and toughnesses. This being the case, over 70 years of research have been devoted to the measurement, understanding, and tailoring of the mechanical properties of these alloys. Despite these efforts, surveys of the current knowledge base and understanding of the mechanical responses of Ti alloys demonstrate that numerous mechanical behaviors have yet to be investigated and explained. It has been noted, but generally not appreciated, that commercially important materials display modest strength differentials near room temperature when deformed under quasi-static loading conditions at modest rates (~10-5 to 10-3 1/s). Under static loading, subtle variations in plastic flow behavior leads to dramatically weaker materials when loaded in tension versus compression. The asymmetric material responses of single and two-phase alloys deformed under monotonic constant rate and creep conditions have been investigated and related to the fundamental slip behavior observed in single crystalline materials. Two-phase titanium alloys containing a majority volume fraction of the alpha (HCP) phase have long been known to undergo creep deformation at lower temperatures (T
Download or read book Microplasticity written by Charles J. McMahon and published by . This book was released on 1968 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Small Fatigue Cracks written by K.S. Ravichandran and published by Elsevier. This book was released on 1999-09-30 with total page 511 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the fully peer-reviewed papers presented at the Third Engineering Foundation Conference on Small Fatigue Cracks, held under the chairmanship of K.S. Ravichandran and Y. Murakami during December 6-11, 1998, at the Turtle Bay Hilton, Oahu, Hawaii. This book presents a state-of-the-art description of the mechanics, mechanisms and applications of small fatigue cracks by most of the world's leading experts in this field. Topics ranging from the mechanisms of crack initiation, small crack behavior in metallic, intermetallic, ceramic and composite materials, experimental measurement, mechanistic and theoretical models, to the role of small cracks in fretting fatigue and the application of small crack results to the aging aircraft and high-cycle fatigue problems, are covered.
Download or read book On the Process of Subsurface Fatigue Crack Initiation in TI 6AL 4V written by James Alfred Ruppen and published by . This book was released on 1978 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue Crack Nucleation and Propagation in Alpha Beta Titanium Alloys written by Harold Margolin and published by . This book was released on 1978 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observations have been made of crack path behavior of alpha-beta Titanium alloys on the surface and in interiors. The fracture surface for an alpha(Ti-0.4Mn) a beta(Ti-10.2Mn), and an alpha-beta alloy (Ti-5.2Mn), have been examined, TEM examiniation of alpha and beta alloys carried out and a study of slip line reversal during load reversal was made. Surface cracking occurs along alpha-beta interfaces and these cracks and joined by link-up. In the interior the crack proceeds along the lines of easiest slip with the result that cracks do not necessarily follow interfaces. The concentration of the crack path in alpha or along alpha-beta interfaces is attributed to higher strain in these regions. Striations are found to be more prominent in beta than in alpha and this is attributed to the higher strain hardening of the alpha phase. Hardening in alpha was attributed to an increase in dislocation density and interaction between twins and dislocations. It was not possible to ascertain whether softening in beta was due to an increase in dislocation density, a decrease in density of the structure giving rise to streaking on diffraction patterns or both. Slip line reversal during reverse straining was found to occur preferentially at grain boundaries.
Download or read book Workhardening Slip Band Formation and Crack Initiation During Fatigue of Titanium written by Dietrich Munz and published by . This book was released on 1973 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The workhardening behavior and slip band formation during fatigue were investigated up to the crack initiation phase of three titanium materials (IMI 115, Contimet 30, Contimet 35) having different impurity contents. The workhardening behavior was studied using fatigue tests with constant strain amplitude. At the beginning of the cyclic loading the stress amplitude decreased afterwards it increased again. The change in stress amplitude could be explained by the dependence of the thermal and the athermal flow stress components on the dislocation density. Similar as in bcc metals the worksoftening is due to an increase in the mobile dislocation density. At low frequencies the plastic strains resulted in the formation of slip bands. With increasing frequency the number and the intensity of the slip bands decreased. No slip bands were observed above 50 Hz. The crack initiated at low frequencies at grain boundaries, in slip bands or transcrystalline without any visible connection with slip bands. At higher frequencies only 'slipless' cracks occurred. (Author).
Download or read book Cyclic Deformation and Fatigue Crack Initiation of a Coherently Precipitating Ni 14 4 At Al Alloy written by Donald Louis Anton and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1997 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation Into the Fatigue Crack Initiation Process in Metals written by Fred W. L. Morris and published by . This book was released on 1985 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: The foundation for a physically derived model of fatigue crack initiation in metals under spectrum loading is described. the work focuses on the microplastic deformation properties of a surface subject to stresses under the bulk elastic limit. A theoretical description of the highly localized plastic strains in individual surface grains, known to be pertinent to aluminum alloys, is developed with the support of high spacial resolution, high sensitivity strain measurements. These are made within individual grains of a Al 2219-T851 model material by a scanning electron microscopy technique. An important finding is that fatigue causes the local flow stresses in individual large surface grains to fall dramatically to less than 50% of their prefatigue values. the local stress-strain behavior is then controlled by the external load spectra, but is greatly influenced by the reaction stresses within a microplastic grain generated when its plasticity is constrained by the essentially elastic surface. Because of the constraint, the local stresses in a grain differ markedly from the applied. The theoretical models developed allow these stresses to be calculated and local mechanical properties of the surface including flow stress and plastic moduli to be estimated from experimental data. An especially interesting anti-clockwise motion of the external stress-local strain hysteresis loop near grain boundaries is observed, and is explained by a simple dual-domain deformation model. It results from an inhomogeneity in mechanical properties with a higher flow stress within the grain near the boundary. Opportunities for the use of such deformation theories to predict crack initiation lifetime are discussed.
Download or read book Fretting Fatigue Crack Initiation Behavior of Ti 6Al 4V written by SA. Namjoshi and published by . This book was released on 2003 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fretting fatigue crack initiation behavior of titanium alloy, Ti-6Al-4V was investigated by using different geometries of the fretting pad. Specimens were examined to determine the crack initiation location and the crack angle orientation along the contact surface. Fretting fatigue experiments were analyzed with the finite element analysis. Several critical plane based parameters were used to predict the number of cycles to fretting fatigue crack initiation, crack initiation location and crack orientation angle along the contact surface. These predictions were compared with the experimental counterparts to study the role of normal and shear stresses on the critical plane in order to characterize fretting fatigue crack initiation behavior. From these comparisons, the fretting fatigue crack initiation mechanism in the tested titanium alloy appears to be governed by the shear stress on the critical plane. However, the role of normal stress on the critical plane at present appears to be unclear.
