Metal-Ceramic Interfaces in Laser Coated Steels: A Transmission Electron Microscopy Study of a Mixture of Iron and Spinel Grains

This paper concentrates on laser coating of a Duplex steel SAF 2205 by bringing a mixture of Cr2O3 and Fe powder into a laser beam. After the laser treatment the Duplex steel transforms into a b.c.c. structure. Transmission electron microscopy observations indicate a proper bonding between substrate and coating consisting of a spinel structure around the composition FeCr2O4 near the interface. In addition, particles with a spinel structure have been observed in the b.c.c. substrate. Crystallographic orientation relationships have been identified for the interfaces of the spinel structure with the b.c.c. matrix using electron diffraction.