Creep of nearly lamellar TiAl alloy containing W
نویسنده
چکیده
Effects of W on the creep resistance of two nearly fully lamellar TiAl alloys with 1.0 and 2.0 at.% W have been investigated. In the low stress regime (LS) a nearly quadratic (1:5 < n < 2) creep behavior was observed. It is found that the addition of W can improve the creep resistance; however, the addition of excess W can result in the formation of b phase, which produces an adverse effect on the creep strength. 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
منابع مشابه
Creep Mechanisms and Interface-Enhanced Deformation Twinning in a Two-Phase _ Lamellar TiAl Alloy
Deformation mechanisms and the role of interfaces in deformation twinning of a two-phase [TiAI (y)GAl (ad] 1 amellar allo\t creep deformed at elevated temperatures have been investigated. Since the multiplication of lattice dislocations \vithin both y and a2 lamellae is verl\’ limited at a lo\v stress level due to a refined lamellar microstructure, the glide of interfacial dislocations on both ...
متن کاملCharacterizations of Lamellar Interfaces and Segregations in a PST-TiAl Intermetallic Alloy by an Analytical Scanning Transmission Electron Microscope
Polysynthetically-twinned titanium aluminide (PST-TiAl), a fully lamellar γ-TiAl+α2Ti3Al dual-phase alloy, is under evaluation for applications in rotary components in aircraft and automobile industries due to its high specific strength, and a high strength-retention capability at elevated-temperatures. However, the low ductility at roomto mid-high temperatures of the material hinders its appli...
متن کاملA Comparison between the Effect of Cr and W Addition on Formation Kinetic of Nanostructure TiAl(γ) Alloy by Mechanical Alloying Route
In this research, mechanical alloying was used to produce Ti-50Al, Ti-45Al-5Cr and Ti-45Al-5W (at%) alloys. The effect of ternary addition (Cr and W) on microstructure and production efficiency of TiAl alloy were investigated. Alloying was performed in a planetary mill and the milling time varying from 5 to 70h. The structural evaluation in these powders was done by X-ray diffraction (XRD) tech...
متن کاملEffects of ultrasonic vibration on the microstructure and mechanical properties of high alloying TiAl
To modify the microstructure and enhance performances, the ultrasonic vibration is applied in the mould casting of TiAl alloy. The effects and mechanism of ultrasonic vibration on the solidifying microstructure and mechanical properties are investigated and the model for predicting lamellar colony size is established. After ultrasonic vibration, the coarse microstructure is well modified and la...
متن کاملRole of Interfacial Dislocations on Creep of a Fully Lamellar TiAl
Deformation mechanisms of a fully lamellar TiAl (γ lamellae: 100 ~ 300Ênm thick, α2 lamellae: 10 ~ 50 nm thick) crept at 760¡C have been investigated. It was found that, as a result of a fine structure, the motion and multiplication of dislocations within both γ and α2 lamellae are limited at low creep stresses (< 400 MPa). Thus, the glide and climb of lattice dislocations have insignificant co...
متن کامل