Principle  :

Surface alloying consists in altering the chemical composition at the surface of a material by simultaneous remelting with an additive element. This additive element can be :

- a coating with controlled thickness
- insulation of a reactive or organic-metallic gas on the melting pool
- injection of alloying powder in the melting pool

The alloying process, very close to the remelting, uses similar treatment conditions (10⁵ W/cm² ; 100 ms). The homogeneity of the alloying is made by convective mixing in the melting pool and by the multiplication of the tracks due to their large width.