A New Process to Enhance Superficial Diffusion in Fe-Ni Alloys at Low Temperatures

ENIO LIMA JR.; V DRAGO

Itapema, Brasil

Workshop; 3RD Brazilian-German Workshop on Applied Surface Science; 2002

Due to the very low diffusion coefficient at temperatures below 670 K the diffusion of nickel into iron to form Fe-Ni alloys cannot be reached by normal annealing processes within practical experimental times. In this paper we show that through a cyclic oxi-reduction process of nickel capped iron grains it is possible to produce Fe-Ni alloys at low temperatures. Notably, after only 5 hours at 623 K with this process we have formed significant portions (19 %) of the ordered Fe50Ni50 tetrataenite phase.