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Explosion pressing of metal powder

Metal powder processing where a powder is mechanically joined by an explosive blast.

Beskrivning
Illustration of Explosion pressing of metal powder

The process

Metal powders are placed in a double-walled tube receptacle [1] which is sealed at both ends with metal plugs where the top is cone shaped. This container is then placed in an open pressure vessel [2] and the gap between the container and the pressure vessel is then filled with explosive [3]. Using a detonator the explosives are ignited which triggers a pressure wave that compresses the metal tube and compresses the metal powder.

Through the buffer between the outer and inner wall of the tube holder as the outer wall accelerate up to a much higher speed which gives a higher compression energy than if a solid tube wall was utilized.

The process allows the metal powder to bind together mechanically into a green body with high density.

The green body then usually undergoes sintering to achieve metallurgical bonding, which improves the material properties.

The sintered body may then undergo various methods to further improve its properties. Some of the most common secondary operations are Carburization, infiltration, restamping, surface compression and impregnation.

Advantages and disadvantages
In comparison with alternative methods
Uniform density
Uses high pressure producing high density
Elimination of subsequent shrinkage
Harmful for operators because of the explosion
Safety precautions for the storage of explosive materials should be taken