Pulsed laser-induced melting of intermediate Cu- Zn phases

The authors have discovered that the and γ 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 offer potential for obtaining quantitative information about the solidification kinetics of metals. The authors have also found that a heteroepitaxial layer of β' brass is formed on the surface of (ordered) γ brass with 63 wt.% Zn following pulsed laser-induced melting. The β' layer is interpreted to mean that the metastable β phase (bcc) formed on the liquid-solid interface as the γ substrate attempted to regrow, and that β ordered to β' (B2) during cooling. The β formation implies that undercoolings > 16 K were attained during the attempted regrowth of the γ phase