fig1

Figure 1. Dendrite morphology and grain orientation distribution within a freckle chain (the direction of solidification is from the bottom to the top). (A) Photograph of the turbine blade casting illustrating the presence of freckle chains (marked with black arrows). (B and C) BSE and orientation images of the freckle chain and the matrix corresponding to the area outlined with a red square in image (A). The interface is outlined with red curves, and carbides and shrinkage cavities are marked with black arrows. The orientation color legend is shown as the top-right inset. (D) Pole figures of the matrix and freckle, respectively, corresponding to the area highlighted in image (B). (E and F) Misorientation of freckle grains relative to the matrix and freckle grain size in four types of samples.