Influence of the Scatter of Sintered Height on the Precision of Parts Sized by a Hydraulic Press

摘要

The scatter of height is an intrinsic characteristic of sintered parts. Depending on material, green density, sintering conditions and part geometry, it may range between ±0.02 and ±0.05 mm. In case of displacement control sizing, the scatter of height affects the sizing force, while in case of force control sizing, it affects the displacement. In both cases, an effect on dimensional and geometrical precision of sized parts may be expected. In order to evaluate this effect, both displacement and force control sizing experiments were carried out, on as sintered parts as well as on ground ones, the latter being characterized by a smaller scatter of height. The aim of this work is that of investigating if the influence of the height scatter is more pronounced in displacement or in force control sizing. The influence is evaluated in terms of the attainable dimensional and geometrical precision of sized parts.