Moderate temperature oxidation protection using nanocrystalline structures

SINGH RAMAN, Monash University, Australia andP. SINGH, University of Connecticut, USA 

Abstract We hypothesised that a nanostructure can bring about dramatic improvements in the oxidation resistance of low chromium iron-chromium alloys at moderate temperatures. A nanocrystaUine Fe-10wt%Cr alloy was foimd to undergo oxidation at a rate that was an order of magnitude lower than its microcrystaUine counterpart. Importantly, the oxidation resistance of nanocry staUine Fe-10wl%Cr alloy was comparable to that of the common corrosion-resistant microcrystalline stainless steels. We outline the difficulties in processing nanocrystaUine iron-chromium ferritic alloys as well as the success in circumventing them. The recently reported roles of nanocrystalline structures in oxidation resistance of a few other systems are also considered. 

Key words nanocrystalline, microcrystaUine, oxidation corrosion resistance, crystaUine and intercrystalhne components, thermal stability. 

Oxidation/corrosion resistance of NC metals and alloys has received very limited research attention. However, NC metals and alloys have been reported to exhibit different oxidation/corrosion resistance from their MC counterparts. It is also emphasised that, besides the interest in investigating the role of NC structures in oxidation/corrosion, another aspect is the possibility 

1 Model of a nanostructured material filled circles represent crystalline component (CC) atoms whereas the open circles represent intercrystalline component (IC) atoms 

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Moderate temperature oxidation protection using nanocrystalline structures... 

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