The Effects of Silicon on Mechanical Properties of Sintered Iron Compacts

Abstract

In order to investigate the effect of silicon on the mechanical properties of sintered iron compacts, 1-4%Si were added to iron compacts, and W and Mo were also added to Fe-3%Si compacts, which showed the improved mechanical properties. They were compacted and sintered by the single-press and sinter techniques, by the double-press and sinter techniques and studied of various mechanical properties. The results were summarized as follows.
(1) Generally, the addition of Si to iron compacts increased the hardness and the tensile strength, however decreased the elongation of the compacts sintered at 1120°C.
(2) In the case of sintering at 1220 and 1300°C, their densification was remarkably accelerated above 2%Si, and therefore gave not only a high tensile strength, but also a high elongation. But the elongation decreased at 4%Si.
(3) The sintered Fe-3%Si compacts, when W and Mo were added, showed the improved mechanical properties. The elongation, however, decreased above 7%W and 5%Mo because of the precipitation of the compounds, namely Fe₂W and Fe₂Mo.
(4) The double-press and sinter techniques generally gave higher strengths than the single-press and sinter techniques, although at high temperatures there were only slight differences between both techniques.