The evaluation of NiAl- and TiAl-based intermetallic coatings produced on the AISI 1010 steel by an electric current-activated sintering method

In this study, NiAl- and TiAl-based intermetallics were coated on the AISI 1010 steel substrate by one-step pressure-assisted electric current-activated sintering (ECAS) process. Ni, Ti and Al elemental powders were mixed by the stoichiometric ratio corresponding to the NiAl and TiAl intermetallic phasesʹ with molar proportion of 1:1. It was observed that the synthesised coatings have a good adherence and many small pores in it. The phases formed in the NiAl coating layers confirmed by XRD analysis were NiAl as a major phase, Ni3Al and NiO trace phases. However, TiAl coatings include Ti3Al, TiO2 and Ti trace phases were detected in addition to TiAl major phase. The distribution of the elements from the surface to the interior on the cross section of the coating layer was verified with energy-dispersive X-ray spectroscopy (EDS) analysis. EDS analysis showed that iron atoms were dissolved in the NiAl and TiAl coating layers during the coating process.