Although the thickness of splat quenched (SQ) foils is normally less then 100 μm the solidified microstructure is usually not homogenous, but rather is determined by a cooling rate dependent nucleation and growth behavior of the different phases. The cooling rate and thus the microstructure changes significantly with distance from the edge to the middle of the SQ foils. Rapidly quenched nickel-vanadium (Ni-V) foils consist of three phases formed during solidification, a Ni-fcc, a V-bcc and a intermetallic σ phase [1-3]. To interpret the microstructure evolution in detail, a special TEM cross section sample preparation was applied. The SQ foil was ground to 30 μm, glued on a copper grid and ion-milled parallel to the foils (Fig.1a). In Ni-49V SQ foils seven typical microstructure regions (see Fig. 1 b) could be identified and were analyzed in detail by TEM investigations in plan view and cross section geometries. Furthermore, three solidification pathways were identified.
Small fatigue crack growth behavior of Ti-6Al-4V produced via selective laser melting: In situ characterization of a 3D crack tip interactions with defects