Warm Die Compaction Process to Achieve Higher Green Density and Green Strength
Demands for better performance and cost competiveness of powder metallurgy (PM) parts have required a new insight to conventional warm compaction processing without heating the powder prior to die filling. It will eliminate the cost and temperature issues related to a separate powder heater. This paper will describe a new powder system designed for warm-die compaction at temperature ranges from 45 to 95 °C (110 to 200 °F). The objective is to achieve an increase of 0.1 g/cm³ over conventional single press/single sinter process and a minimum green strength of 13.8 MPa (2000 psi). Fundamentals of the warm-die compaction process as well as effect of temperature on lubrication and green properties will be presented to aid the parts producer in making high density, high green strength PM parts.