High-Temperature Tensile Properties of Ti-Al-X (X=Cr,W) Consisting of α2, β and γ in Three Phases
| Autor: | Keizo Hashimoto |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Titanium aluminide
Materials science Mechanical Engineering Metallurgy chemistry.chemical_element Condensed Matter Physics Microstructure Durability chemistry.chemical_compound chemistry Mechanics of Materials Ultimate tensile strength Hardening (metallurgy) General Materials Science Atomic ratio Composite material Ternary operation Titanium |
| Zdroj: | Materials Science Forum. :1066-1070 |
| ISSN: | 1662-9752 |
| DOI: | 10.4028/www.scientific.net/msf.706-709.1066 |
| Popis: | Gamma titanium aluminides (γ-TiAl) have been investigated extensively for more than 25 years, since they are considered to be candidate materials for advanced jet engine components, automobile exhaust valves, turbo-chargers, and so on. Many researchers have reported that the mechanical properties of γ-TiAl have been improved by micro-alloying and thermo-mechanical microstructure control. Recently, γ-TiAl entered a new era by being applied to low-pressure turbine blades in newly developed commercial jet engines. In order to spread their applications further, material durability and affordability have become key issues. The tensile properties of the Ti-Al-X (X=Cr or W) have been studied intensively at various strain rates and test temperatures in a vacuum atmosphere. It has been demonstrated that the additions of a few atomic percent of Cr or W to γ-TiAl shifts the phase stability drastically and creates relatively fine-grain microstructures consisting of α2+β+γ in three phases. Although the microstructures of Ti-46at%Al-2.7at%Cr and Ti-45at%Al-1.9at%W show similar morphology, the high-temperature mechanical properties of each indicate distinguishable properties. The former specimens have demonstrated the capability of super-plastic deformation at temperatures above 1323K; the latter specimens, however, have showed relatively higher tensile strength than those of the other specimens having ternary compositions (Ti-Al-X). The differences in the tensile properties of Ti-Al-X (X=Cr or W) have been discussed in conjunction with microstructures and the effects of solid-solution hardening due to W atoms. |
| Databáze: | OpenAIRE |
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