Anisotropy of secondary reaction zone formation in aluminized Ni-based single-crystal superalloys

Distribution of the secondary reaction zone (SRZ) on the (1 0 0) plane was investigated in the aluminized Ni-based single-crystal superalloy TMS-75. Preferential formation of the SRZ was observed along the {0 0 1}〈1 1 0〉 directions, whereas the SRZ was not formed along the {0 0 1}〈1 0 0〉 directions. This result can be explained by the anisotropy of recrystallization in the single-crystalline substrate.