Technology and mechanical properties of advanced γ-TiAl based alloys
| Autor: | Wilfried Wallgram, Limei Cha, Helmut Clemens, Thomas Schmölzer, Gopal Das, Volker Güther |
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| Rok vydání: | 2009 |
| Předmět: | |
| Zdroj: | International Journal of Materials Research. 100:1021-1030 |
| ISSN: | 2195-8556 1862-5282 |
| Popis: | The present paper summarizes our progress in establishing a novel production technology for -TiAl components to be used in advanced aircraft engines. In the beginning the main emphasis is put on the design of a -TiAl based alloy which exhibits excellent hot-workability. Then, the development of a “near conventional” hot-die forging route for this type of intermetallic material is described. Finally, the effect of two-step heat-treatments on the microstructure and the mechanical properties is discussed. Because of the small “deformation window” hot-working of -TiAl alloys is a complex and difficult task and, therefore, isothermal forming processes are favoured. In order to increase the deformation window a novel Nb and Mo containing -TiAl based alloy (TNMTM alloy) was developed, which solidifies via the β-phase and exhibits an adjustable β/B2-phase volume fraction. Due to high volume fractions of -phase at elevated temperatures the alloy can be hot-die forged under near conventional conditions, which means that conventional forging equipment with minor and inexpensive modifications can be used. Examples for the fabrication of -TiAl components employing a near conventional forging route are given. With subsequent heat-treatments balanced mechanical properties can be achieved. The results of tensile and creep tests conducted on forged and subsequently heat-treated TNMTM material are presented. |
| Databáze: | OpenAIRE |
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