Effect of Die Wall Lubrication on Warm Compaction Powder Metallurgy

摘要

Die wall lubrication was applied on warm compaction powder metallurgy in hope to reduce thernconcentration level of the admixed lubricant since lubricant is harmful to the mechanical property of the sinteredrnmaterials. Iron-based samples were prepared by die wall lubricated warm compaction at 135℃ and 175℃, usingrnpolytetrafluoroethylene (PTFE) emulsion as die wall lubricant. A compacting pressure of 700 MPa and 550 MPa werernused. The admixed lubricant concentration ranging from 0 to 0.6 wt.% was used in this study. Results show that inrnaddition to the decrease in ejection forces, green density of the compacts increased linearly with the decrease inrnadmixed lubricant content. Mechanical property of the sintered compacts increase sharply when the admixed lubricantrnconcentration reduced to 0.125 wt.% or less. No scoring was observed in all experiments.