Mechanical Properties of Sintered Iron Sheets Containing Dispersed Oxide Particles

Abstract

Oxide (SiO₂ orAl₂O₃) particles were cmbeded to iron powder, and they were pressed, sintered at 850°C for 1 hr in a hydrogen atmosphere, rolled and annealed. The recrystallized grain size and the textures of the sheets were examined, and the reiatienship between these characteristics and tensile properties of the sheets were discussed.
Effects of fine oxide particles added (amorphous SiO₂ and γ-Al₂O₃: about 200Åφ) on the mechanical properties of the sheet were found to be remarkably high comparing with those of larger size (α- SiO₂and α-Al₂O₃: about 2μmφ). In this case, the elongation decreased in general owing to fine recrystallized grain size in the matrix, although its increase appeared in the range of 0.4-0.7 vol. %addition in iron sheets. This fact suggested that the elongation was affected by the annealing texture which had been changed by additive content in the sheet.
As a result, it was found that the dispersed oxide particles and the restraint of recrystallization of the sheet by these particles improved the strength of the sheet, and exerted a major influence on the other mechanical behaviours. Moreover, it was considered that a compound was formed at the inter-face between iron and oxide (SiO₂ or Al₂O₃) during the sintering process.