Deposition of hard and/or corrosion resistant, single and multielement coatings on ferrous and nonferrous alloys in a fluidized bed reactor

Heat treatments of alloys in fluidized bed reactors have been carried out for more than 25 years. Recently, this technology has been used for surface engineering applications in the deposition of hard and/or corrosion resistant layers. In the present paper we used fluidized bed technology (FBT) to deposit hard boride coatings on steel and titanium alloys and multielement Cr–Al–Hf and Yt coatings on steel alloys. The coatings were characterized using optical microscopy, electron microscopy and X-ray diffraction (XRD). The coatings porosity thickness and microhardness were evaluated as a function of processing parameters.