The crystallography of a Nb/Nb 5 Si 3 lamellar microstructure formed by Nb 3 Si decomposition has been investigated by transmission election microscopy. Upon solidification of a Nb-10?at.% Ti-20?at.% Si alloy, the high-temperature phase Nb 3 Si is retained at room temperature. During annealing at 1673?K, the Nb 3 Si phase transforms into the Nb and Nb 5 Si 3 (D8 l ) phases with a lamellar microstructure through a eutectoid reaction. The orientation relationship between Nb and Nb 5 Si 3 is determined by selected-area diffraction analyses as , and  Nb // Nb5Si3 . The present orientation relationship is explained by good atomic matching on the close-packed planes along the near close-packed directions.
ASJC Scopus subject areas
- Condensed Matter Physics