Fig.2: Status diagram of Fe-Al |
The combination of destructive processes like wear, thermal fatigue and the following pyro-cracking, the metalization, or corrosion of aluminum, is called wash-out damage. NIPRE was born from the need of improving the barrier to protect the mould when Fe is coming in contact with liquid Al during the production part, one of the first causes of metalization and of stuck weld.
As a second step, we evaluated how high is the nobility of the surface and of the homogeneity compared to a substratum which must also resist to wear. On Fig.3 the table shows the formation heat at ambient temperature for the different compounds created by iron with one of the three light elements N, C, O and some of the typical coatings:
|
Compound
|
Formation heat Kcal/ mole (ambient temperature)
|
|
Fe2-3N
|
metastable
|
|
Fe4N
|
-2.6
|
|
Fe3C
|
metastable
|
|
Fe3O4
|
-265
|
|
TiN
|
-80.4
|
|
CrN
|
-30
|
|
Cr2O4
|
-270
|
Fig.3: Formation heat Kcal/ mole |
NIPRE®
