Powder Compaction at Very High Pressures
Previous researchers in powder compaction have been limited to pressures of about 1500 MN/m2, with 1000 MN/m2 being the more usual limit. This paper describes some compaction work performed at much higher pressures.
Pressure-density results and hardness measurements are presented for a nickel-base superalloy compacted at pressures up to 4000 MN/m2 together with scanning electron micrographs of the compacted particles. Even at 4000 MN/m2 the powder reached only 94 per cent of its theoretical density, and was not sufficiently consolidated to permit any but the most delicate handling. The density and hardness values, however, showed no tendency to ‘level-off’ at this pressure.
The pressure-density results are further discussed in terms of a recent theory relating various stages of compaction to the extent of plastic deformation.
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