Aluminising of mild steel using Al-11Si-1.2Cu baths

Abstract

Hot-dip aluminising of mild steel was done using Al-11Si-1.2Cu (at %) bath at 750 C for dipping time ranging from 300 to 3600 seconds. Aluminised layer was investigated using scanning electron microscope and energy dispersive spectroscopy. The intermetallic layer consisted of 4 distinct layers, namely, ?5-(Al7Fe2Si), ?-FeAl3, ?-Fe2Al5 and ?1-(Al,Si)5Fe3. Total intermetallic layer thickness was following parabolic growth kinetics with time. Total thickness was increasing predominantly due to increase in Fe2Al5 layer, which itself was following parabolic growth behaviour. Total intermetallic layer thickness was smaller compared to intermetallic layer thickness reported using pure aluminium or aluminium silicon baths. 2013 CAFET-INNOVA TECHNICAL SOCIETY.