Abstract
Copper and iron powders were compacted in a closed die or extruded against back pressure at high or low speed, and the effect of the forming speed on the properties of powder products was discussed.
Copper powder compacts obtained at high speed (-11m/sec) had lower density and more uniform hardness distribution than those compacted at low speed.
Copper and iron pre-sintered compacts could be extruded without cracks through high speed extrusion against back pressure higher. than 1400kg/cm2 and 3000kg/cm2, respectively, while both of them cracked in low speed extrusion.
The density and strength of products increased and the hardness variation on the transverse sections decreased with increasing back pressure.
