DOE Investigation of anisotropic dimensional change during sintering of iron-copper-carbon

Dimensional change on sintering and its effect on the dimensional precision of iron-copper-carbon ring- shaped parts produced by powder metallurgy (PM) were investigated. The effect of different variables on dimensional change was studied by design of experiments (DOE). The type and composition of the powder, as well as the height of the parts, were considered. The effect of chemical composition was significant on all the dimensions, while the other variables had only a slight effect on the dimensions in the compaction plane. To determine the anisotropy of the dimensional change upon sintering, the wall thickness in the compaction plane was considered, which is directly related to shrinking/swelling. No systematic effect of the parameters investigated on the dimensional precision of the PM parts was observed, and the excellent precision of green parts is maintained after sintering. The anisotropic behavior did not significantly affect the dimensional precision of the parts evaluated.