Surface composition of the steel powders pre-alloyed with manganese
Artikel i vetenskaplig tidskrift, 2010

The determination of the surface oxide layer composition is vital to facilitate the adjustment of the sintering conditions for sufficient removal of the surface oxides for providing strong metal bonding between the metal particles during sintering. To systematically investigate the composition, morphology and thickness of the surface oxide the influence of manganese content from 0.3 to 1.8 wt.% on the surface products composition in the case of water atomized steel powder was evaluated. Analysis of the powder surfaces by X-ray photoelectron spectroscopy and high-resolution scanning electron microscopy in combination with X-ray microanalysis showed that powder particles in all cases are covered by heterogeneous oxide layer, composed of particulate features of thermodynamically stable oxides (Cr-Mn-Si) and homogeneous iron surface oxide layer in between. For increasing alloying content the fraction of stable oxide cations in the surface layer increases linearly, whereas the thickness of the iron oxide layer decreases. Moreover, from the investigation of the sintering and degassing behavior by thermal analysis coupled with mass-spectrometry (TG/DTA + MS), three different stages of carbothermal reduction process were observed and their correlation with surface oxides composition was established during sintering in argon.

Thermal analysis

sofc interconnect

o system



sintered steels




XPS analysis



PM steels

Carbothermal reduction

Surface oxides


Eduard Hryha

Chalmers, Material- och tillverkningsteknik, Yt- och mikrostrukturteknik

Christian Gierl

Technische Universität Wien

Lars Nyborg

Chalmers, Material- och tillverkningsteknik, Yt- och mikrostrukturteknik

Herbert Danninger

Technische Universität Wien

Eva Dudrova

Institute of Materials Research Slovak Academy of Sciences

Applied Surface Science

0169-4332 (ISSN)

Vol. 256 3946-3961


Bearbetnings-, yt- och fogningsteknik