Speaker
Description
Intermetallic $\gamma$ titanium aluminide based alloys are structural multiphase materials applied at temperatures up to 800°C. During service, they often have to withstand high tensile stresses and resist creep, for example when used in aircraft engines. Due to their diverse crystal structures, the mechanical responses of the individual phases (i.e. $\gamma$ (TiAl), $\alpha_2$ (Ti3Al), and $\beta_o$ (TiAl)) are quite different from each other and in part also temperature-dependent. In order to resolve these responses individually, in situ high-energy x-ray diffraction (HEXRD) tensile tests were performed with TNM samples (Ti-43.5Al-4Nb-1Mo-0.1B in at.%) consisting of different microstructures. In this way, the transition between the elastic and plastic range in the individual phases could be observed very precisely. These experimental tests were supported by a detailed finite element (FE) simulation, where the actual microstructure was realistically modeled based on data gathered by microstructural analysis. Several software tools were used, namely NEPER (microstructure modeling) and ABAQUS (FE software). The simulation sequence was automated using the programming languages Python and Fortran. Utilizing the combination of experiment and simulation, it is shown that the interplay of the different phases is crucial for the understanding of the macroscopic behavior of the material.