Download or read book The Influence of Beta Phase Decomposition on Dp dT of Titanium Alloys written by Mary Ann Hill and published by . This book was released on 1986 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Masters Theses in the Pure and Applied Sciences written by Wade H. Shafer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, SIld disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna and broader dissemination. tional publishing house to assure improved service Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 30 (thesis year 1985) a total of 12,400 theses titles from 26 Canadian and 186 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work.
Download or read book Fundamental Studies of Beta Phase Decomposition Modes in Titanium and Related Alloy Systems written by and published by . This book was released on 1992 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: Throughout this final grant from AFOSR, the P.I. spent much of his time in the preparation of generic overviews of numerous major topics in diffusional phase transformations. These overviews dealt with homogeneous nucleation, interphase boundary structures in Ti-base alloys, effects of interphase boundary structure upon growth kinetics, shear vs. diffusional transformation mechanism (with emphasis upon linking macroscopic observations with processes proceeding at the atomic level), the mechanism (and definitions) of the bainite reaction and the influence of alloying elements upon the growth kinetics of grain boundary allotriomorphs of proeutectoid ferrite. A major overview of the ledge mechanism in vapor-crystal, liquid-crystal and crystal-crystal diffusional phase transformations, and a still broader overview of atomic mechanisms of diffusional nucleation and growth are nearing completion. Collaborative research with Dr. M.G. Hall of the University of Birmingham, U.K., on topics concerned with distinction between diffusional and shear mechanisms of transformation from the standpoints of crystallography and surface relief effects, has also made progress.
Download or read book Fundamental Studies of Beta Phase Decomposition Modes in Titanium Alloys written by H. I. Aaronson and published by . This book was released on 1985 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: These studies on diffusional phase transformations in titanium and related alloy systems are intended to develop further the scientific base needed to design alloys based upon these transformations which may exhibit significantly improved combinations of mechanical properties. Kinetics of beta yields alpha sub m massive transformation were compared with those of grain boundary proeutectoid alpha precipitation in Ti-Ag and Ti-Co alloys, using measured or calculated nucleation and growth kinetics data and Cahn analysis of overall transformation kinetics of grain boundary nucleated reactions, successfully explained presence of massive transformation only in Ti-Ag and alpha allotriomorphs only in Ti-Co. New explanation developed, on thermodynamic grounds, for replacement of 'normal' proeutectoid alpha plates with a well-formed 'black plates' alpha + lower reaction temperatures. Bainite nodules in hypereutectoid Ti-Cr and in hypoeutectoid Ti-Co and Ti-Fe were found to exhibit misfit dislocation and ledge structures. Nodules in Ti-Cr grew at approximately volume diffusion-controlled rates; but reanalysis is now needed in terms of ledge mechanism. Eutectoid alpha is often found to differ slightly in orientation from adjacent proeutectoid aplha plates.
Download or read book Decomposition of the Beta phase in Titanium Alloy Ti 17 written by J.. BECHET and published by . This book was released on 1985 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Decomposition of the Beta Phase in Titanium Alloys written by R. B. GULLBERG and published by . This book was released on with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Ternary Additions on the Decomposition of Metastable Beta phase Titanium Alloys written by J. C. WILLIAMS and published by . This book was released on with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Influence of Beta Instabilities on the Early Stages of Nucleation and Growth of Alpha in Beta Titanium Alloys written by Soumya Nag and published by . This book was released on 2008 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Microstructural evolution in Beta Titanium alloys is an important factor that governs the properties exhibited by them. Intricate understanding of complex phase transformations in these alloys is vital to tailor their microstructures and in turn their properties to our advantage. One such important subject of study is the nucleation and growth of alpha precipitates triggered by the compositional instabilities in the beta matrix, instilled in them during non equilibrium heat treatments. The present work is an effort to investigate such a phenomenon. Here studies have been conducted primarily on two different Beta-Titanium alloys of commercial relevance- Ti5553 (Ti-5Al-5Mo-5V-3Cr-0.5Fe), an alloy used in the aerospace industry for landing gear applications and, TNZT (Ti-35Nb-7Zr-5Ta), a potential load bearing orthopedic implant alloy. Apart from the effect of thermal treatment on these alloys, the focus of this work is to study the interplay between different alpha and beta stabilizers present in them. For this, advanced nano-scale characterization tools such as High Resolution STEM, High Resolution TEM, EFTEM and 3D Atom Probe have been used to determine the structure, distribution and composition of the non equilibrium instabilities such as beta phase separation and omega phase, and also to investigate the subsequent nucleation of stable alpha. Thus in this work, very early stages of phase separation via spinodal decomposition and second phase nucleation in titanium alloys are successfully probed at an atomic resolution. For the first time, atomically resolved HRSTEM Z-contrast image is recorded showing modulated structures within the as-quenched beta matrix. Also in the same condition HRTEM results showed the presence of nanoscale alpha regions. These studies are revalidated by conventional selected area diffraction and 3D atom probe reconstruction results. Also TEM dark field and selected area diffraction studies are conducted to understand the effect of quenching and subsequent aging of omega precipitates. Using 3D atom probe tomography, the elemental partitioning involved in coarsening of omega is investigated in detail. Finally by performing a series of well planned heat treatments, an effort is made to reason out the influence of these instabilities on the morphology, volume fraction and nucleation site of alpha.
Download or read book A Transmission Electron Microscopy Investigation of the Early Stages of Beta Phase Decomposition in Three Metastable Beta Titanium Alloys written by Robert Hayden Dick and published by . This book was released on 1988 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Deformation and Decomposition of Metastable B C C Titanium Alloys written by C. G. Rhodes and published by . This book was released on 1976 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of microstructure on mechanical properties of metastable beta titanium alloys was investigated, with emphasis on the influence of alpha-phase precipitation on tensile strength and ductility. A commercial alloy, Ti-3Al-8V-6Cr-4Mo-4Zr (Beta-C) has been aged to produce both Type 1 alpha (obeying the Burgers orientation relation) and 2 alpha (not obeying the Burgers relation) as hardening precipitates in the beta matrix. Although a direct comparison of Types 1 and 2 alpha could not be made, there did not seem to be any direct correlation between precipitate type and mechanical properties. Rather, it has been found that overaging to produce a coarse distribution of relatively large (>1000 A) non-coherent alpha precipitates provides the best combination of strength and ductility. The same strength can be achieved with much finer distribution of small (approximately 100-200 A) coherent alpha precipitates, but with much reduced ductility.
Download or read book The Precipitation of Alpha Phase in Metastable Beta Phase Titanium Alloys written by C. G. Rhodes and published by . This book was released on 1975 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the results of a microstructural study of the crystallography, morphology and kinetics of formation of alpha-phase during decomposition of the metastable beta-phase in a Ti-Mo-Al ternary alloy and a Ti-Mo binary alloy.
Download or read book Decomposition of Beta Phase in Titanium Alloy Vt22 written by I. S. POLKIN and published by . This book was released on with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Beta Processing on Titanium Alloys written by James E. Coyne and published by . This book was released on 1968 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1974 with total page 1138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Deformation of Dual Phase Titanium Alloys written by Jikang Zhong and published by . This book was released on 2012 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: The deformation behaviour of dual phase titanium alloys has been investigated using experimental and modelling methods. The motivation for conducting this investigation was to improve understanding of the deformation behaviour of dual phase titanium alloys in order to contribute to the long term goal of reducing manufacturing cost and improving production efficiency. Dual phase titanium alloys have been studied under two deformation conditions: high speed machining and uniaxial compression, which represent respectively high rate and low rate deformation. The microstructure and texture of the serrated chips obtained during high speed cutting of the dual phase Ti-6Al-4V alloy have been studied. The cutting speed, depth of cut and the orientation of the sample were found to have a significant influence on the deformation of serrated chips. Adiabatic shear bands were found in the serrated chips due to non-uniform deformation of Ti-6Al-4V alloy and deformation heating. In addition, there is reasonable agreement between the predicted texture using the visco-plastic self-consistent (VPSC) model and the measured texture using the electron backscatter diffraction (EBSD) technique indicating that the deformation in an adiabatic shear band is due to shear.The deformation behaviour of dual phase Ti-Mn alloys has been characterised with uniaxial compression at different temperatures and strain rates. The flow stress plateau phenomenon was observed in all the Ti-Mn alloys in the low to medium temperature range (27~500°C), which is attributed to the occurrence of dynamic strain aging (DSA). The flow softening behaviour was observed in dual phase Ti-Mn alloys in the high to sub-transus temperature range (600~800°C), which is attributed to the change in volume fraction of [beta] phase during deformation due to the rise in temperature caused by deformation heating. The yield point phenomenon was observed when the Ti-Mn alloys are above their [beta] transus temperatures. This phenomenon has been attributed to the multiplication of dislocations at the beginning of plastic deformation and dynamic recovery in the following plastic deformation. The strain rate sensitivity of Ti-Mn alloys was low in the low to medium temperature range and thus the effect of strain rate on deformation is not obvious. However, it was high in the high to sub-transus temperature range and thus the effect of strain rate on the deformation is significant. The 0.2% proof stress was found to increase with the volume fraction of [beta] phase. The strain rate sensitivity was found to decrease with the volume fraction of [beta] phase in the low to medium temperature range because the strain rate sensitivity of the [alpha] phase is higher than the [beta] phase. However, the strain rate sensitivity was found to increase with the volume fraction of [beta] phase at high temperatures because the strain rate sensitivity of the [beta] phase becomes larger than the [alpha] phase. A considerable temperature rise was observed during compression of the Ti-Mn alloys and this indicates that the effect of deformation heating on deformation is not negligible. A composite model has been constructed to predict the plastic stress-strain curves of the dual phase Ti-Mn alloys using the in-situ behaviour of the component phases. The partition of stress and strain between the component phases has been accounted for by using three partitioning assumptions: iso-strain, iso-stress and iso-work. There was good agreement between the predicted curves and the experimental curves. It was found that the in-situ behaviour of the [alpha] phase is different in different dual phase Ti-Mn alloys and it exhibits a linear relationship with the volume fraction of [beta] phase when the dominant matrix is the same. The modelling results in the low to medium temperature range indicate that most of the plastic deformation occurs in the localised shear band, which is consistent with the experimental observation that the dual phase Ti-Mn alloys were more susceptible to the formation of localised shear bands. In addition, it was found that a change in the dominant matrix in dual phase Ti-Mn alloys significantly influences the in-situ behaviour of the [alpha] phase. The modelling results in the high to sub-transus temperature range indicate that the flow softening behaviour observed in dual phase Ti-Mn alloys is related to the change in volume fraction of the [beta] phase and the diffusion of Mn during the deformation.
Download or read book X ray Measurement of Beta Phase in Titanium Alloys written by Matthias F. Comerford and published by . This book was released on 1957 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Omega Phase on Selected Properties of Beta III Titanium Alloy written by F. H. Froes and published by . This book was released on 1975 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: The program objective is to increase the elastic modulus, or modulus-density ratio, of heat treatable beta titanium alloys, while maintaining adequate levels of strength, ductility and toughness by suitable thermomechanical processing and thermal treatments. Material from production and laboratory heats, centering on the Beta III alloy (Ti-11.5Mo-6Zr-4.5Sn), was evaluated by correlating microstructural features with mechanical properties for material subjected to various thermal-mechanical process sequences and thermal treatments. The results show that the elastic modulus can be increased by (1) an increase in the proportion of the high modulus alpha phase, (2) judicious increase in the amount of omega, and (3) an increase in the molybdenum content of the beta phase. Transformation kinetics within the omega formation temperature range and the nature of the omega to alpha transformation are discussed.
