Microstructure Formation and Tailoring of the Intermetallic TiAl Alloy Produced by Direct Laser Deposition

摘要

This study investigates the microstructure morphology in a single-track wall of Ti-47Al-2Cr-2Nb alloy produced by direct laser deposition. The as-deposited wall mainly exhibited an alternative-band microstructure containing a dendrite band and alpha(2)/gamma lamellar band, which is considered to result from the influence of the heat affected zone. A tailoring method was proposed and alternative-band microstructures with various equiaxed colony fractions, and even nearly fully equiaxed colony microstructures, were successfully obtained.