Influence of g-phase on the high- temperature oxidation of NiAl-Fe alloys
The oxidation of NiAl, NiAl-20at.%Fe and NiAl-30at.%Fe at 1000-1100 °C in air has been studied. Pure NiAl shows excellent oxidation resistance due to the formation of an Al2O3 layer. NiAl-20Fe also shows good oxidation resistance due to the formation of an Al2O3 scale on a <FONT FACE="Symbol...
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| Outros Autores: | , |
| Formato: | article |
| Idioma: | eng |
| Publicado em: |
1999
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| Texto completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14391999000300011 |
| País: | Brasil |
| Oai: | oai:scielo:S1516-14391999000300011 |
| Resumo: | The oxidation of NiAl, NiAl-20at.%Fe and NiAl-30at.%Fe at 1000-1100 °C in air has been studied. Pure NiAl shows excellent oxidation resistance due to the formation of an Al2O3 layer. NiAl-20Fe also shows good oxidation resistance due to the formation of an Al2O3 scale on a <FONT FACE="Symbol">b</font>-phase substrate. Moreover, some nodules consisting of mixed oxides of Fe and Ni grow over the ductile <FONT FACE="Symbol">g</font>-phase surface incorporated to the <FONT FACE="Symbol">b</font>-phase substrate. NiAl-30Fe alloy undergoes a much faster oxidation due to the formation of a non-protective Fe and Ni-rich scale, which is extremely susceptible to spallation. The addition of Fe to NiAl is detrimental to its oxidation resistance. |
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