Download or read book Evaluation of a Gamma Titanium Aluminide for Hypersonic Structural Applications 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 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium matrix composites (TMCs) have been extensively evaluated for their potential to replace conventional superalloys in high temperature structural applications, with significant weight-savings while maintaining comparable mechanical properties. New gamma titanium aluminide alloys and an appropriate fiber could offer an improved TMC for use in intermediate temperature applications (400-800 C). The purpose of this investigation is the evaluation of a gamma titanium aluminide alloy with nominal composition Ti-46.5Al-4(Cr,Nb,Ta,B)at.% as a structural material in future aerospace transportation systems, where very light-weight structures are necessary to meet the goals of advanced aerospace programs.Johnson, W. Steven and Weeks, Carrell E.Langley Research CenterMECHANICAL PROPERTIES; STRUCTURAL DESIGN; TITANIUM ALUMINIDES; HYPERSONIC FLIGHT; HEAT RESISTANT ALLOYS; X-43 VEHICLE; TEMPERATURE; FEASIBILITY ANALYSIS; THERMAL PROTECTION; METAL MATRIX COMPOSITES; FAILURE MODES; YIELD STRENGTH

Download or read book Evaluation of a Gamma Titanium Aluminide for Hypersonic Structural Applications written by Carrell Elizabeth Weeks and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium matrix composites have been extensively evaluated for their potential to replace conventional superalloys in high temperature structural applications, with significant weight-savings while maintaining comparable mechanical properties. The purpose of this investigation is the evaluation of a gamma titanium aluminide alloy with nominal composition Ti-46.5Al-4(Cr, Nb, Ta, B)at.% as a matrix material for use in intermediate temperature applications (400-800ʻC) in future aerospace transportation systems, as very light-weight structures are needed for cost and weight reduction goals. Mechanical characterization testing was performed over the potential usable temperature range (21-800ʻC). Thermal expansion behavior was evaluated, as thermal mismatch of the constituents is an expected problem in composites employing this matrix material. Monotonic testing was conducted on rolled sheet material samples to obtain material properties. The alloy exhibited good strength and stiffness retention at elevated temperatures, as well as improved toughness. Monotonic testing was also conducted on specimens exposed to elevated temperatures to determine the degradation effects of high temperature exposure and oxidation. The exposure did not significantly degrade the alloy properties at elevated temperatures; however, room temperature ductility decreased. Analytical modeling using AGLPLY software was conducted to predict the residual stress state after composite consolidation as well as the potential mechanical behavior of [0]4 laminates with a -̂MET matrix. Silicon carbide (Ultra-SCS) and alumina (Nextel 610) fibers were selected as potential reinforcing materials for the analysis. High residual stresses were predicted due to the thermal mismatch in the materials. Laminates with Nextel 610 fibers were found to offer the better potential for a composite in this comparison as they provide a better thermal match. Coupons of SCS-6/-̂MET were manufactured with different volume fractions (10% and 20%). Both manufacturing attempts resulted in transverse cracking in the matrix from the residual thermal stress.

Download or read book Gamma Titanium Aluminide Alloys written by Fritz Appel and published by John Wiley & Sons. This book was released on 2011-08-04 with total page 763 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first book entirely dedicated to the topic emphasizes the relation between basic research and actual processing technologies. As such, it covers complex microstructures down to the nanometer scale, structure/property relationships and potential applications in key industries. From the contents: * Constitution * Thermophysical Constants * Phase Transformations and Microstructures * Deformation Behaviour * Strengthening Mechanisms * Creep * Fracture Behaviour * Fatigue * Oxidation Resistance and Related Issues * Alloy Design * Ingot Production and Component Casting * Powder Metallurgy * Wrought Processing * Joining * Surface Hardening * Applications and Component Assessment

Download or read book Gamma Titanium Aluminides 2003 written by Young-Won Kim and published by Minerals, Metals, & Materials Society. This book was released on 2003 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt: A March 2003 meeting provided a forum for scientists to share information on progress in gamma TiAl alloys. Selected papers from the meeting, 77 in all, are presented here, and cover applications, fundamentals, alloy design and development, processing, joining, microstructure-property evaluation, an

Download or read book Gamma Titanium Aluminide Alloys 2014 written by Young-Won Kim and published by John Wiley & Sons. This book was released on 2014-09-24 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a collection of papers presented at the 4th International Symposium on Gamma TiAl Alloys (ISGTA 2014) that was held in conjunction with the 2014 Annual Meeting of The Minerals, Metals & Materials Society. Papers discuss and assess advances in application and implementation experience in current alloys, fundamental aspects in current gamma alloy materials technology, new processes development and assessment, and emerging new alloys, their potentials and limitations, and breakthroughs. Papers that originated in the panel discussion of the symposium are intended to help the scientific community realize the limitations of current alloys materials and processes and discuss possible solutions. Six topic areas selected for this purpose included: Wrought-processed alloys: status, dilemmas and pathways to future Cast alloys for aero engine applications: status, issues, and barriers to advances Cast alloys for turbocharger wheels: status and barriers to widespread applications Emerging new alloys: justification, potentials, status, and future Novel processes: justification, potential vs. realization issues, and future Future applications and realistic pathways to them

Download or read book Gamma Titanium Aluminides written by Young-Won Kim and published by Minerals, Metals, & Materials Society. This book was released on 1995 with total page 1036 pages. Available in PDF, EPUB and Kindle. Book excerpt: This two-volume publication is a comprehensive update of the fundamental and practical issues confronting the research, development and application of gamma titanium aluminides.

Download or read book Gamma Titanium Aluminides 1999 written by Young-Won Kim and published by Minerals, Metals, & Materials Society. This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 106 papers were selected from the presentations and have undergone stringent peer review. They consider nearly every aspect of current gamma-alloy technology, such as fundamental science, alloy development and design, process development, flow and fracture, creep behavior, microstructure and property evaluation, environmental behavior, and applications. The specific topics include powder metallurgy structures for use in various high-temperature aerospace applications, experiments and atomistic simulations of the deformation of polysynthetically twinned single crystals with near-hard orientations, the interplay of thermodynamics and transformation kinetics on microstructure development, solid solution strengthening mechanisms, studying localized strain at notches using displacement mapping and microstructural characterization, and the influence of gaseous species on the oxidation behavior at high temperature. The illustrations tend to be of high quality.

Download or read book Gamma Titanium Aluminide Manufactured by Electron Beam Melting written by and published by . This book was released on 2010 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of the Biocompatibility of Gamma Titanium Aluminide as an Implant Material written by Diego Ferney Castañeda Nuñez and published by . This book was released on 2003 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microstructural Analysis of Gamma titanium Aluminide Based Intermetallic with Addition of Alumina Former Elements written by Emadella Rifai and published by . This book was released on 2008 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optimization and Characterization of Gamma Titanium Aluminide Sheets Produced by Hot Isostatic Pressing of Tape cast Monotapes written by Alicia Gayle Adams and published by . This book was released on 2005 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A powder metallurgy route based on hot isostatic pressing (HIPing) of tape-cast monotapes was investigated for the direct fabrication of dense thin sheets of gamma titanium aluminide ([gamma]-TiAl)--Abstract, leaf iii.

Download or read book Titanium Aluminide Applications in the High Speed Civil Transport written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-25 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is projected that within the next two decades, overseas air travel will increase to over 600,000 passengers per day. The High Speed Civil Transport (HSCT) is a second-generation supersonic commercial aircraft proposed to meet this demand. The expected fleet of 500 to 1500 aircraft is required to meet EPA environmental goals; the HSCT propulsion system requires advanced technologies to reduce exhaust and noise pollution. A part of the resultant strategy for noise attenuation is the use of an extremely large exhaust nozzle. In the nozzle, several critical components are fabricated from titanium aluminide: the divergent nap uses wrought gamma; the nozzle sidewall is a hybrid fabrication of both wrought gamma face sheet and cast gamma substructure. This paper describes the HSCT program and the use of titanium aluminide for its components. Bartolotta, Paul A. and Krause, David L. Glenn Research Center NASA/TM-1999-209071, NAS 1.15:209071, E-11627

Download or read book Thermal Coatings for Titanium Aluminum Alloys written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-23 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium aluminides and titanium alloys are candidate materials for use in hot structure and heat-shield components of hypersonic vehicles because of their good strength-to-weight characteristics at elevated temperature. However, in order to utilize their maximum temperature capability, they must be coated to resist oxidation and to have a high total remittance. Also, surface catalysis for recombination of dissociated species in the aerodynamic boundary layer must be minimized. Very thin chemical vapor deposition (CVD) coatings are attractive candidates for this application because of durability and very light weight. To demonstrate this concept, coatings of boron-silicon and aluminum-boron-silicon compositions were applied to the titanium-aluminides alpha2 (Ti-14Al-21Nb), super-alpha2 (Ti-14Al-23-Nb-2V), and gamma (Ti-33Al-6Nb-1Ta) and to the titanium alloy beta-21S (Ti-15Mo-3Al-3Nb-0.2Si). Coated specimens of each alloy were subjected to a set of simulated hypersonic vehicle environmental tests to determine their properties of oxidation resistance, surface catalysis, radiative emittance, and thermal shock resistance. Surface catalysis results should be viewed as relative performance only of the several coating-alloy combinations tested under the specific environmental conditions of the LaRC Hypersonic Materials Environmental Test System (HYMETS) arc-plasma-heated hypersonic wind tunnel. Tests were also conducted to evaluate the hydrogen transport properties of the coatings and any effects of the coating processing itself on fatigue life of the base alloys. Results are presented for three types of coatings, which are as follows: (1) a single layer boron silicon coating, (2) a single layer aluminum-boron-silicon coating, and (3) a multilayer coating consisting of an aluminum-boron-silicon sublayer with a boron-silicon outer layer. Cunnington, George R. and Clark, Ronald K. and Robinson, John C. Langley Research Center ALUMINIDES; ENVIRONMENTAL TESTS; HYPERSONIC VEHI...

Download or read book Microstructural Characterization Of alpha sub 2 gamma Titanium Aluminides written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-phase titanium/aluminium alloys with microalloying additions are of interest due to the high strength-to-weight ratio they can provide in automotive and aircraft applications. This paper describes the microstructure of boron doped alloys with chromium, niobium, and tungsten.

Download or read book Gamma Titanium Aluminides written by International Symposium on Gamma Titanium Aluminides and published by . This book was released on with total page 1024 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aphrodite a Greek Goddess written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Oxide Thermal Stability on Gamma Titanium Aluminide written by and published by . This book was released on 1990 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface composition plays an important role in hydrogen embrittlement of the TiAl-based structural alloys proposed for NASP. A clear understanding of the thermal stability of the oxide on the various titanium aluminides will give important insight into the way that hydrogen reacts with these materials in the initial step of the hydriding process. The present work addresses these issues by using surface probes to analyze the thermal stability of an oxide formed under atmospheric conditions on gamma titanium aluminide. X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) have been employed to characterize the surface composition and bonding when the oxidized material is annealed to (approximately)600°C in vacuum. The measurements show that the oxygen is largely preserved at the surface while the aluminum-oxide bond becomes more prominent.