Isostatic Compaction of Metal Powders in Conventional Molding Tools

摘要

Isostatic compaction of metal powders in conventional metal tooling can be achieved through the use of pliable mold inserts made from vinyl plastisols. The plastisol formulation (by weight) which appeared to be most suited for pliable molds consisted of 100 parts vinyl chloride resin, 60 parts plasticizer, and 3 part epoxy resin. Curing the plastisol mix at a temperature of 350 = 10F for 30 = 2 minutes/inch of mold thickness proved to be satisfactory. Compaction studies were conducted on several metal powders: aluminum, iron, copper, and tungsten. A comparison of the compressibilities of these powders is made when compacted using conventional and isostatic techniques. It appears that significant improvements in density can be obtained by isostatically compacting materials whose yield stress in shear behaves according to the law suggested by Mohr. It is recommended that the use of pliable mold inserts within conventional metal tooling be considered as a means of isostatically compacting powders. (Author)