In situ hot-stage observations of structural transformation in a laser surface-melted TiAl intermetallic alloy

The structural transformation in a laser surface-melted TiAl intermetallic alloy has been observed during in situ heating. The effect of temperature on the observed metallographic changes in microstructure is discussed. The results show that during heating to certain temperatures, the dendritic structure formed by laser surface-melting can transform into an apparently fine-grain structure, which may provide a suitable substrate for superplastic/diffusion bonding.