The structural metastability of metallic alloys produced by Selective Laser Melting

The structural metastability is a peculiar characteristic of the metallic alloys produced by Selective Laser Melting. It is due to the large solidification undercooling. Such a metastability may give rise to mechanical properties largely different from those of the as-cast and wrought materials. In case of the Ti6Al4V alloy and of the 17-4PH steel, as built properties are not suitable for the applications, and the structure has to be stabilized through specific heat treatments. In case of the CoCrMo alloy, as-built properties are instead suitable for applications. In case of 17-4PH, the properties resulting from the structural metastability may open new perspectives for applications in different fields.