NiAl Behavior at Plasma Spray Deposition

摘要

The behavior of stoichiometric and near-stoichiometric NiAl at plasma spray deposition, without and with a bond coat, for coating layers realization on a low alloyed steel substrate has been investigated and is presented. In all variants, NiAl particle melting and their welding at the impact with substrate were observed. Furthermore, a relatively compact and adherent coating layer was formed and the NiAl was found to maintain its stability. These are all important factors for assuring the coating layer oxidation and corrosion resistance. Good results from the coating structure and adherence to the substrate points of view were obtained for the 45:55 Ni:Al composition, without a bond coat but adopting an Ar protective surrounding of plasma jet. The high resistance to corrosion of 45:55 NiAl composition was further validated through corrosion tests.