It was discovered that the beta and gamma brasses of Cu-Zn exhibit clearly resolved increases in reflectance upon melting with a 30 ns ruby laser, which allow their melt durations to be readily measured. This system thus offers potential for obtaining quantitative information about the solidification kinetics of metals. It was also found that a heteroepitaxial layer of beta (prime) brass is formed on the surface of (ordered) gamma brass with 63 wt percent Zn following pulsed laser induced melting. The beta (prime) layer is interpreted to mean that the metastable beta phase (bcc) formed on the liquid-solid interface as the gamma substrate attempted to regrow, and that beta ordered to beta (prime) (B2) during cooling. The beta formation implies that undercoolings greater than 16 K were attained during the attempted regrowth of the gamma phase.
Presented at the Materials Research Society Fall Meeting
- Pub Date:
- Phase Diagrams;
- Reaction Kinetics;
- Lasers and Masers