Abstract
This paper discusses the sulphidation/oxidation protection offered by multilayer CrAlYN/CrN coatings etched by Cr, CrAl and Y ions, deposited by a combined high power impulse magnetron sputtering (HIPIMS)/unbalanced magnetron sputtering (UBM) technique on a Ti–45Al–8Nb alloy (at%). The test was performed at 750 °C in an environment of H2/H2S/H2O yielding low oxygen (10−18 Pa) and high sulphur (10−1 Pa) partial pressures for up to 1000 h. The results show that all the exposed materials underwent uneven degradation; some places developed a thin protective oxide scale (Al,Cr)2O3 with a tiny sulphur content, whilst others developed a porous non-protective TiO2 + Al2O3 scale as well with a tiny sulphur content.
Original language | English |
---|---|
Pages (from-to) | 45-60 |
Number of pages | 16 |
Journal | Materials and Corrosion |
Volume | 65 |
Issue number | 1 |
Early online date | 21 Jun 2012 |
DOIs | |
Publication status | Published - Jan 2014 |
Externally published | Yes |
Keywords
- HIPIMS
- TiAl
- UBM
- Corrosion
- Multilayer coating
- Oxidation
- Sulphidation