fracture and fatigue of gamma based titanium aluminides by Allister William James

Cover of: fracture and fatigue of gamma based titanium aluminides | Allister William James

Published by University of Birmingham in Birmingham .

Written in English

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Thesis (Ph.D) - University of Birmingham, School of Metallurgy and Materials, 1995.

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Statementby Allister William James.
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Open LibraryOL21764431M

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Bin Liu, Yong Liu, in Titanium Powder Metallurgy, Abstract. Titanium aluminide (TiAl)-based alloys are developed for high-temperature applications in aerospace and automotive industries because of their attractive properties, such as low density, high specific strength, high specific stiffness, and good high-temperature properties.

This chapter discusses TiAl-based alloys prepared with. Keywords: gamma titanium aluminides, high fracture and fatigue of gamma based titanium aluminides book fatigue, fat igue crack propagation Abstract.

The fatigue properties of a TiAl-2Cr-2Nb alloy obtained by electron beam melting. Fatigue-crack propagation in gamma-based titanium aluminide alloys at large and small crack sizes.

Fatigue-Crack Propagation in Gamma-Based Titanium Aluminide Alloys at Large and Small Crack Sizes Conference Paper (PDF Available) in MRS Online Proceeding Library.

Gamma titanium aluminides have a specific modulus which is 50–70% greater than that for titanium alloys and retain their stiffness to higher temperatures.

The specific strengths of gamma alloys exceed those of polycrystalline nickel alloys at all temperatures and even those for titanium alloys at temperatures greater than ≈ by: Abstract.

A study has been made of the effect of temperature (between 25 °C and °C) on fracture toughness and fatigue-crack propagation behavior in an XD-processed, γ-based titanium aluminide intermetallic alloy, reinforced with a fine dispersion of ∼1 vol pct TiB 2 particles. It was found that, whereas crack-initiation toughness increased with increasing temperature, the crack-growth.

All fights reserved X/94 $ + 00 MAGANESE SEGREGATION AND INTERGRANULAR FRACTURE IN GAMMA-BASED TITANIUM ALUMINIDES W.O.

Soboyejox, K. Loux and M. McConnell+ XDepartment of Materials Science and Engineering, The Ohio State University, West 19th Avenue, Columbus, OH +General Electric Corporate Research and Development. Resistance to fatigue crack growth in these alloys is related to the density and distribution of slip in the plastic zone directly ahead of the crack-tip during fatigue crack growth.

y, Acta Metallurgica Inc. INTRODUCTION The fatigue and fracture behavior of binary gamma titanium aluminides, (TiAI) has been studied by a number of. Gamma alloys, based on the gamma titanium aluminide (y-TiAl) intermetallic compound, are emerging as a revolutionary engineering material for high-temperature structural applications.

Gao, M., Dunfee, W., Miller, C, Wei, R.P. and Wei, W., Thermal Fatigue Testing System for the Study of Gamma Titanium Aluminides in Gaseous Environments, to be published in Thermal-Mechanical Fatigue Behavior of Materials: 2nd Volume, ASTM STPAmerican Society for Testing and Materials, Philadelphia Google Scholar.

Limited experiments on gamma and gamma-based titanium aluminides have shown that the tensile stress- strain and fracture behavior of both single-phase and two-phase gamma titanium aluminide alloys can be degraded by hydrogen and hydrogenous gases at both ambient and elevated temperatures, primarily through a loss in ductility [2,3,].

Gamma Titanium Aluminides Applications Gamma TiAl Applications at GE Aviation M. Weimer, and T. Kelly Current Status of Mass Production of Gamma Titanium Aluminide Alloy Turbine Rotors in Turbochargers and Future.

Statistical Modeling of Microstructural Effects on Fatigue Behavior of [alpha]/[beta] Titanium Alloys --A Probabilistic Framework for the Modeling of Fatigue in a Lamellar XD[superscript TM1] Gamma Titanium Aluminide Alloy --Probabilistic Fatigue Damage Assessment for Short Crack Growth --Probabilistic Modeling of Fatigue Crack Growth in Ti-6Al.

Gamma Titanium Aluminides Michael P. Brady, William J. Brindley, James L. Smialek, and Ivan E. Locci Authors' Note: All compositions are in atomic percent. The excellent density-specific properties of the gamma class of titanium aluminides make them attractive for intermediate-tem-perature (°(7.) aerospace applica-tions.

A common feature of Gamma Titanium Aluminides is the heterogeneous character of their microstructure. This heterogeneity causes failure processes to be progressive, with a continuous transition between a diffused and a localized mode of damage, the relative contribution of both modes to failure being determined by the degree of randomness of.

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 Reviews: 1. Abstract. Ambient-temperature fracture toughness and fatigue crack propagation behavior are investigated in a wide range of (γ+α 2) TiAl microstructures, including single-phase γ, duplex, coarse lamellar (1 to 2 mm colony size (D) and µm lamellar spacing (λ)), fine lamellar (D ∼ µm, λ= to µm), and a powder metallurgy (P/M) lamellar microstructure (D=65 µm, λ= µm).

The fatigue and fracture mechanisms in TiAl-xMn (x = to at. pct) gamma-based titanium aluminide alloys are elucidated. Unlike most gamma alloys, which fail predominantly by transgranular fracture at room temperature, fracture in ternary TiAl-xMn alloys is shown to occur mainly by intergranular failure.

The incidence of intergranular failure increased with increasing annealing. @article{osti_, title = {High temperature oxidation and fracture behavior in a gamma titanium aluminide alloy}, author = {Kameda, J and Gold, C R and Lee, E S and Bloomer, T E and Yamaguchi, M}, abstractNote = {High temperature fracture behavior in air has been studied in single grained titanium aluminides (Ti at.%Al) with two different lamellar orientations with respect to the.

Abstract. Essential features of the microstructures which can be produced via phase transformations in two-phase alloys based on γ-TiAl and α 2-Ti 3 Al are described. Effects of microstructure on the deformation and fracture behaviour are discussed with a view to finding possible pathways towards improved ductility and toughness in such alloys.

McKelvey, K. Venkateswara Rao, R. Ritchie, "High temperature fracture and fatigue-crack growth behavior of an XD gamma based titanium aluminide intermetallic alloy"; submitted to Metallurgical and Materials Transactions, Fatigue crack initiation and growth were examined in cast and HIP’ed γ-TiAl XD.

It was found that fatigue crack growth rates were higher at C than C, but that ∆Kth was also higher. Temperature excursions between and C during fatigue crack growth resulted in retardation of the crack growth rate, both on heating and cooling; however heating from to C at a ∆K.

cracking of a gamma- based titanium aluminide alloy William D. Dunfee Lehigh University Titanium Aluminides 3 Thermal Fatigue 5 RELATED WORK ON TITANIUM ALUMINIDES 6 fracture surfaces of a specimen thermally cycled in airfrom 25 to oe.

Lifetime: 2, cycles Elemental aluminum and titanium foils were roll bonded at room temperature with different rolling strains, as the first step in the processing of gamma titanium aluminides. A probabilistic framework is introduced for the modeling of fatigue damage in three gamma-based titanium aluminides: TiAl-2Mn-2Nb+vol.%TiB 2, TiAl-2Mn-2Nb+vol.%TiB2 and TiAl-2Cr-2Nb.

This includes empirical stress-life and fracture mechanics approaches to the estimation of material reliability or the risk of failure. This thesis presents the room temperature mechanical properties of two y-based titanium aluminides. The fracture toughness, fatigue crack growth resistance (FeGR), and tensile properties of duplex, fully lamellar, and near fully lamellar microstructures have been assessed.

Fatigue crack path and fracture surfaces were analyzed using optical and scanning electron microscopes. Results and discussion constant, m, for all titanium aluminides investigated was gamma base titanium aluminides due to crack branching, blunting, microcrack toughening and bridging mecha- nisms (Gnanamoorthy et al )• The high.

Kruzic, J. Campbell, A. McKelvey, H. Choe, and R. Ritchie, "The Contrasting Role of Microstructure in Influencing Fracture and Fatigue-Crack Growth in g-Based Titanium Aluminides and Large and Small Crack Sizes," accepted to be in Gamma Titanium Aluminides, @article{osti_, title = {Notch fracture in {gamma}-titanium aluminides}, author = {Mendiratta, M G and Goetz, R L and Dimiduk, D M}, abstractNote = {The notch fracture behavior of two {gamma}-titanium aluminide alloys, having duplex and fully lamellar microstructures, has been investigated as a function of notch geometry and test temperature.

In recent years intermetallic compounds have attracted a great deal of attention as structural materials. Among the intermetallics, gamma titanium aluminides .gamma.-TiAl) are considered to be closest to application.

Compared to Ni-based materials these alloys offer opportunities for substantial weight reductions, and compared to titanium alloys they offer better creep, oxidation and burn.

Modeling thermal exposure effects on fatigue of gamma titanium aluminides Article in Materials Science and Engineering A s –– June with 2 Reads How we measure 'reads'. A study has been made of the effect of temperature (between 25 C and C) on fracture toughness and fatigue-crack propagation behavior in an XD-processed, {gamma}-based titanium aluminide intermetallic alloy, reinforced with a fine dispersion of {approximately}1 vol pct TiB{sub 2} particles.

This book is the first of its kind to compile microstructural and fracture features for titanium alloys and titanium aluminides as well as capture its fractographic features together with the conditions that produced s: 1. Gamma-TiAl based intermetallic alloys have received considerable attention of late as candidate materials for high-temperature aerospace and auto-motive applications [1,2].

In comparison to conven-tional gas-turbine engine materials [1–4], titanium aluminides composed primarily of the g-phase pos-sess and 50% lower density than conventional.

The contrasting role of microstructure in influencing fracture and fatigue-crack growth in gamma-based titanium aluminides at large and small crack sizes, Kruzic, J.

J., Campbell J. P., McKelvey A. L., Choe H., and Ritchie R. O., Gamma Titanium AluminidesTMS Annual Meeting, (). A study of fatigue damage in lamellar polycrystals of gamma-TiAl based intermetallic alloys have been undertaken.

Using electropolished fatigue specimens, it has been found that most of fatigue failures occur due to cracks initiating internally. Surface damage prior to failure has been very minimal. On the Influence of Thermomechanical Processing on the Fracture Behavior of Gamma-Based Titanium Aluminides.

Effects of Alloying with Cr and Nb. Materials and Manufacturing Processes: Vol. 11, No. 3, pp. Ductility and fracture toughness at room and intermediate temperatures continue to be lower than the desired values for production implementation. In this paper, progress made towards improving strain-controlled fatigue resistance of nickel and titanium aluminides is outlined.

History. Titanium aluminides are titanium alloys that are based on the formation of two intermetallic phases or compounds.

These alloys include, for example, the α-2 alloys that are based on the Ti 3 Al intermetallic phase and a variant of the Ti 2 AlNb phase, and the gamma titanium aluminide alloys (TiAl). The family of TiAl alloys was developed a few decades ago and it was the subject of.

Gamma Titanium Aluminides Proceedings of Symposium Sponsored by the Materials & Processing Committee of ASM International Materials Science Critical Technology Sector, and the High Temperature Alloys Committee, and the Titanium Committee of the Structural Materials Division (SMD) of TMS (The Minerals, Metals & Materials Society) ; Held During the TMS Annual Meeting in.

high-temperature properties such as strength retention, creep and stress rupture, and fatigue resistance (Lui and Stiegler, ; Millett, Gray and Bourne, ). In improving the mechanical properties of gamma titanium aluminides, Plansee AG of Austria has developed new generation of gamma titanium called Gamma .The fatigue properties of a TiAl-2Cr-2Nb alloy obtained by electron beam melting (EBM) with a patented process has been examined by conducting high cycle fatigue tests performed at different loading ratios both at room temperature and at high temperatures, comparable to those experienced by the components during service.

Some tests have been conducted in the superlong life regime well.Influence of Mechanical Surface Treatments on the Fatigue Performance of the Gamma TiAl Alloy TiAl-9NbC p Thermo-Mechanical Fatigue Behaviour of the Gamma-Titanium Aluminide TNB-V5 with Near-Gamma Microstructure.

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