Prakt. Met. Sonderband 52 (2018) 105 
SL ve Bl 
(a) 9 ym, 6 min (b) 3 pm, 3 min 
os Lovo pm 
aon = rr 
class oie (c) 3 um, 15 min (d) 1 ym, 3 min 
nterreted a 
. adhesion of Fig. 3: Preparation of a highly porous sample, taper section 10°, overview 
10 be spent 
hing steps. in 
omatic grind: 
1 bonded dia- 
ed by around 
2 remove the ey [Rr £ou pin 250 pm 
longer than 3 ‘ = 5 
(a) 3 um, 2 min (b) 3 um, 6 min (c) 3 um, 15 min (d) 1 um, 3 min 
amage to the 
ravided a bet Fig. 4: Detail view of the preparation of a porous oxidation sample, taper section 10° 
‘aakout. How- 
polishing (Fig. 3b). Only after polishing for typically 15 min with 3 ym (Fig 3c) can the true 
extent of the scale be seen. The final preparation step on a napped cloth with 1 pm dia- 
0 bom a ab mond suspension (Fig. 3d) mainly improves the contrast between different oxide phases 
is explained and removes the last scratches from the metal, but has no significant impact on scale 
naked na damage in either a positive or negative way. Fig. 4 shows a magnified section of the same 
| re pls sample during various stages of polishing with much the same progression. The final pol- 
i are ishing step (Fig. 4d) also reveals all of the metallic inclusions in the scale. 
ples is suff 
a and coarse