抄録
The effect of powder lubrication and mechanical properties on room temperature and warm compacting behavior has been investigated by examining various kinds of metal powders. Compacting process is modeled by analyzing the compacting behavior based on the punch load-stroke diagram.
It is understood that the model of the punch load-stroke diagram is composed of straight line (Stage I: powder flow), hyperbolic curve (Stage II: plastic deformation or fracture) and straight line (Stage III: bulk elastic strain). Larger or more spherical particles having lower friction allow lower pressure compacting in Stage I. In stage II, lower elastic modulus and yield point, higher ductility and n-value, and lower surface friction of particles are effective to allow lower pressure compacting.
It is confirmed that the method of die wall lubrication is better than powder lubrication to obtain higher density, though the latter method is suitable for green compacts with regular configuration under lower compacting pressure. Warm compaction enhancing good lubricating effect significantly affects decreasing compacting pressure through stage I and II. The compacting pressure is effectively reduced to get higher density only when powder particle indicates lower yield point and higher ductility.
