Coating A was deposited on a fcc surface without any
specific nucleation step while Coatings B–E were deposited
on modified fcc surfaces. It was previously established
that the growth textures of Al2O3 coatings could
be manipulated by different nucleation procedures. In
this work three different nucleation procedures were
used. An important difference characterising the applied
nucleation steps was the oxidation potential of the furnace
atmosphere, which varied from about 5 ppm H2O
(Coating B) to about 20 ppm (Coating D). It is emphasised
that all the experimental Al2O3 Coatings A–D were
deposited using exactly the same process parameters, the
only difference being the nucleation step. The process
parameters used to deposit Coating E were identical to
those used for Coating C except for the deposition time,
which was 60 min instead of 560 min for Coatings A–D.
The process parameters used to deposit the Al2O3 layers
are given in Table 3.