The effects of zinc stearate in compaction of metal powders are experimentally investigated in the aspects of apparent density, flow rate, coefficient of friction between the die and green compacts, mechanical strength of green compacts, coefficient of lateral pressure, consolidation equation, and density distribution of compacts. The zinc stearate is used as the powder lubricant and also die lubricant.
The results obtained are as follows:
1) When the zinc stearate of 0.1-2.0% is added, the apparent density of metal powders is increased, and when more than 2% this is decreased conversely.
2) The effect of die lubricant on the decrease of friction coefficient is far superior to that of powder lubricant on it.
3) The coefficient of lateral pressure is little affected by adding the zinc stearate.
4) When the zinc stearate is used as a powder lubricant, the mechanical strength of the powder compacts is decreased.