Titanium aluminides are intermetallic materials, which exhibit a high specific strength up to temperatures of about 800°C. Therefore, these alloys show a high potential to replace heavier nickel base alloys in automotive and aerospace applications. Due to the intrinsic properties of this new lightweight structural material the process window for any hot-working procedure has to be considered as rather limited compared to metallic materials. Thus, even very small variations of the chemical composition or the hot-working process parameters can lead to an unacceptably high scrap rate. The aim of this thesis was the investigation of the hot-workability of a high-niobium containing titanium aluminide alloy. The dependence of the flow stress on the deformation speed at different temperatures was characterized. Moreover, the influence of the anisotropy and the inhomogeneity of the starting material on the hot-working properties was investigated. In addition, samples of an industrial scale forging-process were examined as well. This study enabled the determination of process parameters that allow sound hot-working of the investigated alloy in a conventional forging process. Besides the characterization of the hot-workability another aim of this work was the evaluation of different non-destructive testing methods regarding their usability for titanium aluminides. Since their low fracture toughness the detection of critical cracks in massive components is hardly possible.
|Translated title of the contribution||Conventional Forging of titanium aluminides|
|Award date||7 Apr 2006|
|Publication status||Published - 2006|
Bibliographical noteembargoed until null
- Titanium aluminide Material
- intermetallic Hot-workability Forging
- conventional Flow detection Non-destructive testing