On the surface of the substrate, Ni forms a γ and γ‘ phase, first with Al and then β phase, and Ni and Al are substituted by Pt or forms a γ-Ni, Pt first, and then γ-(Ni,Pt)Al. Finally β-(Ni,Pt)Al.
I got confused. What happened inside? If coating forms some PtAl 2 phases in the beginning of the CVD process, can I eliminate the PtAl 2 phase by raising the temperature?