High temperature oxidation behaviour of laser surface alloyed iron-silicon coatings on iron

Iron silicide (FesSi) coatings of composition Fe-16 at% Si and Fe-25 at% Si have been produced by laser surface alloying on pure iron substrates with predeposited silicon powder. The coatings showed excellent adherence without any pores or cracks. They were compositionally and microstructuraly homogeneous, exhibiting two to three times higher surface hardness values than pure iron. High temperature oxidation resistance of the coatings were tested in the temperature range 1173-1273 K in static pure oxygen ( P ~ , = 13.3 k ~ a ) . Their superiority compared to bulk alloys and CVD coatings is discussed.