Microstructure and Performance of Al-Coating on AZ31 Prepared by Pack-Cementation with Different Heating Methods

In this study, Al-containing coatings were prepared on the surface of AZ31 magnesium alloy by pack-cementation through box-type furnace heating (BFH) and induction (IH) methods. Phases, microstructure, composition, performance characterized X-ray diffraction technique (XRD), secondary electron imaging (SEI), backscattered (BSEI), energy dispersive spectroscopy (EDS), Vickers hardness test potentiodynamic polarisation test, respectively. The results show that method has a significant impact phases, thickness, coatings. Both aluminized layers are relatively flat dense, no obvious second phase is observed. thickness layer IH sample much larger than BFH because diffusion rate greater BFH. composed an outermost β-Mg2Al3 inner γ-Mg17Al12 near side substrate. evolution different methods discussed. microhardness corrosion behavior also investigated indicate resistance better BFH, related to content intermetallic compound phase.