The 800°C isothermal and cyclic oxidation of alloys based on Co-7Al-7W (at.%) was examined. Cr, Fe and Si additions were beneficial. Repeated oxide bilayers formed during cycling of non-Cr alloys, which were not protective (>100μm thick). In these layers, the outer was Co3O4 and the inner, a porous Co3O4 and Al2O3 mixture. 10at.% Cr substitution for Co was sufficient to produce a protective, ~1μm thick scale which contained an outer layer of Al2CoO4, a very thin (100nm) middle layer of Cr2O3 and an inner layer of Al2O3. Therefore protective oxide scales are possible in γ/γ', Co-Co3(Al,W) superalloys.
|Number of pages||14|
|Publication status||Published - 1 Jan 2014|
- thermal cycling
- oxidation behaviour
- Co–Al–W superalloys
FingerprintDive into the research topics of 'Effect of alloying on the oxidation behaviour of Co-Al-W superalloys'. Together they form a unique fingerprint.
- Design, Manufacturing And Engineering Management - Lecturer B