  The effect of isothermal pre-oxidation treatments on the \b{eta}-(Ni,Pt)Al +
Ren\'e N5 system degradation is here reported. The oxidation treatments were
carried out from 900 (mostly {\theta}-Al2O3 growing conditions) to 1200{\deg}C
(mainly {\alpha}-Al2O3 growing conditions) for 5 h, under a purified Ar-stream
with a fixed pO2= 1 x 10-5 atm. Results are discussed based on the correlation
between the structural, microstructural and chemical properties of the
\b{eta}-(Ni,Pt)Al BC showing that pre-oxidation parameters have an important
effect on the multi-elemental counter diffusion phenomena along BC. For
instance, a significant BC+IDZ thickness increase of 55% at 1200 {\deg}C was
observed with respect to as-received sample just after 5 h of oxidation
resulting in a severe BC degradation.
