Variation of crystal orientation during epitaxial growth of dendrites by laser deposition.

A nickel-based superalloy was deposited onto a single crystal substrate based on epitaxial laser metal forming (E-LMF). The microstructure development in two depositions has been researched. For the first time, the crystal orientation of dendrites varying beyond 20° was found when the dendrites deflected in deposition. In addition, a new grain boundary was found between different orientation dendrites in a grain, and the detected grain boundary angle was 23°. The result shows that flowing field in laser pool is responsible for this phenomenon. [ABSTRACT FROM AUTHOR]