Cladding of an Fe-aluminide coating on mild steel using pulsed laser assisted powder deposition

Iron-aluminide has the potential to be used as a superior high temperature oxidation and sulfidation resistant coating on less corrosion resistant materials. A process for producing a dense, hard, iron-aluminide coating on a mild steel substrate has been successfully developed using pulsed laser assisted powder deposition (LAPD). The clad deposition rate, measured by clad height, increased with an increase in duty cycle of the laser, either through an increase in pulse duration or frequency, an increase in powder feed rate and decrease in substrate velocity. A simple analysis using concepts of an effective interaction time, energy and powder deposition density, all of which were determined by laser duty cycle, powder feed rate and substrate velocity, was developed. Taken together these three parameters allow a determination of the processing conditions that will give rise to a high quality Fe-Al clad on mild steel with a specified height. (C) 2002 Published by Elsevier Science B.V.