Basischarakterisierung von intermetallischen Titanaluminid-Legierungen für die Anwendung im Abgasturbolader
Research output: Thesis › Doctoral Thesis
Intermetallic titanium aluminide (TiAl) alloys are used for high-temperature application like turbine blades and turbocharger wheels due to their low density, high strength and creep properties as well as their oxidation resistance. In this thesis, a TNM alloy with a nominal composition of Ti-43.5Al-4Nb-1Mo-0.1B (in atomic percent) was investigated as wrought alloy for near-net shape blanks of turbocharger wheels. Wrought parts are expected to improve the strength and ductility as compared to cast parts. Subsequent machining provides improved aerodynamic properties. The aim of this thesis was the characterization of the material during the whole processing route. Therefore, light optical, scanning electron and transmission electron microscopy were applied to assess the microstructural features. For further characterization X-ray diffraction, hardness measurements as well as tensile and creep tests were conducted on elevated temperatures up to 800 °C. Furthermore, an alternative production route by the use of plasma arc melting was established and new alloy variants of TNM with Si for improved casting properties developed, whereby first creep tests were applied for the estimation of their application potential.
|Translated title of the contribution||Basic characterization of an intermetallic titanium aluminide alloys for application in automotive turbochargers|
|Publication status||Published - 2015|