How electron beam melting tailors the Al-sensitive microstructure and mechanical response of a novel process-adapted y-TiAl based alloy
Publikationen: Beitrag in Fachzeitschrift › Artikel › Forschung › (peer-reviewed)
Autoren
Organisationseinheiten
Externe Organisationseinheiten
- Friedrich-Alexander-Universität Erlangen-Nürnberg
Abstract
Additive manufacturing of lightweight intermetallic γ-TiAl based alloys combines process-related freedom of design with material-specific excellent high-temperature properties. Nevertheless, where locally melting the powder by an electron beam, there is a risk that Al evaporates due to its high vapor pressure, causing compositional and microstructural variations. This work investigates the impact of different process parameters on the total and local Al-content as well as the resulting as-built and heat-treated microstructure in a complex multiphase Ti-44.8Al-4.1Nb-0.7W-1.1Zr-0.4Si-0.5C-0.1B (at.%) alloy. The examinations applied are complementary, employing electron microscopy, X-ray spectroscopy and diffraction experiments with synchrotron X-ray radiation, supported by numerical simulations. The mechanical anisotropy of the heat-treated microstructure was analyzed by micro-hardness measurements. The results demonstrate that the amount of γ-TiAl phase decreases with increasing energy input of the electron beam in the as-built and heat-treated microstructure owing to the total and local loss of Al. Besides, the investigations of the crystal orientations within the multiphase alloy reveal a preferred orientation of the γ phase at high energy inputs. This follows from the fact that the preferred γ orientation is inherited through directional solidification of the β phase. The obtained process-microstructure-property relationships show that tailor-made material properties of additively manufactured γ-TiAl components are achievable.
Details
Originalsprache | Englisch |
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Aufsatznummer | 110187 |
Seitenumfang | 13 |
Fachzeitschrift | Materials and Design |
Jahrgang | 212.2021 |
Ausgabenummer | 15 December |
Frühes Online-Datum | 20 Okt. 2021 |
DOIs | |
Status | Veröffentlicht - 15 Dez. 2021 |