Formation of nitride phases in the nitriding of porous iron

Autor: S. Meshashti, Yu. N. Moskalenko, V. G. Gorbach
Rok vydání: 1991
Předmět:
Zdroj: Soviet Powder Metallurgy and Metal Ceramics. 30:283-286
ISSN: 1573-9066
0038-5735
DOI: 10.1007/bf00795957
Popis: When sintered iron with a certain porosity (14–20%) is saturated with nitrogen, the amount of absorbed N2 and the depth of the nitride layer increase jumpwise. If we regard the porous material as a biphase mixture (of pores and iron particles), such a phenomenon can be associated with the jumpwise increase of the effective diffusion coefficient at a certain quantitative ratio of the phases (the so-called percolation effect of diffusion). When porous iron is nitrided, a peculiar morphological form of the nitride phases forms in the diffusion layer; this, in distinction to the acicular nitrides, which are typical of the nitriding of compact iron, has a comparatively equiaxial shape and sinuous phase boundaries.
Databáze: OpenAIRE