High velocity adiabatic impact powder compaction

Abstract

A method and apparatus for powder compaction using high velocity adiabatic impact. A quantity of powder material is impacted with a power ram at a controlled velocity in a single controlled impact on the powder material at a controlled specific impulse or specific kinetic energy to adiabatically compact the powder material into a workpiece with a relative density of 95% or above without additional processing such as preliminary compaction, pre-compaction sintering, post-compaction sintering, pre-heating of the powder material (warm compaction), lubrication or multiple impacts.

1 . A method for compacting a powder material using high velocity adiabatic impact, comprising:
 impacting a quantity of powder material with a power ram at a controlled velocity in a single controlled impact on said powder material at a controlled specific impulse or specific kinetic energy to adiabatically compact said powder material into a workpiece with a relative density of 95% or above without additional processing such as preliminary compaction, pre-compaction sintering, post-compaction sintering, pre-heating of the powder material (warm compaction), lubrication or multiple impacts.   
   
   
       2 . A method in accordance with  claim 1 , wherein said relative density is 96-99% or above. 
   
   
       3 . A method in accordance with  claim 1 , wherein said relative density is 99% or above. 
   
   
       4 . A method in accordance with  claim 1 , wherein said power ram velocity and impulse delivered by said power ram are determined according to one or more of a mass, material type, particle size and particle size distribution of said powder material. 
   
   
       5 . A method in accordance with  claim 1 , wherein said power ram delivers a specific impulse of at least approximately 15-18 Newton-seconds/gram or a specific kinetic energy of least approximately 380-520 Joules/gram to said powder material. 
   
   
       6 . A method in accordance with  claim 1 , wherein said workpiece has a mass within a range of approximately 0.01 grams to approximately 30 kg. 
   
   
       7 . A method in accordance with  claim 1 , wherein said power ram velocity is not less than approximately 8 meters/second when impacting said powder material. 
   
   
       8 . A method in accordance with  claim 5 , wherein said power ram velocity is at least approximately 30-50 meters/second when impacting said powder material. 
   
   
       9 . A method in accordance with  claim 1 , wherein said powder material comprises one or more of metal, ceramic, plastic, wood or combinations of the foregoing. 
   
   
       10 . A method in accordance with  claim 1 , wherein said workpiece is one of an intermediate shaped workpiece for use in final forming by further adiabatic processing or by conventional methods, a near net shape workpiece for use in final forming by further adiabatic processing, or a final net shape component that requires no further forming, polishing or finishing operations. 
   
   
       11 . A method in accordance with  claim 1 , wherein said method is performed with an additional ram power stroke applied following said single controlled impact and prior to ejection of said workpiece. 
   
   
       12 . A method in accordance with  claim 11  wherein said ram power stroke has a duration of up to approximately 100 milliseconds and a magnitude of up to approximately 2500 tons. 
   
   
       13 . A method in accordance with  claim 1 , further including one or more processing operations of preliminary compaction of said powder material, pre-compaction sintering, post-compaction sintering or other heat treatment of said workpiece, final forming of said workpiece, component machining, ingot manufacturing, and mill processing to produce sheet, plate, strip, bar, wire, forging billets, extruded shapes, pipes, and tubing in one or more unalloyed or alloyed grades. 
   
   
       14 . A method for compacting a powder material using high velocity adiabatic impact, comprising:
 impacting a quantity of powder material with a power ram at a controlled velocity in a single controlled impact on said powder material at a controlled specific impulse or specific kinetic energy to adiabatically compact said powder material into a workpiece with a relative density of 95% or above without additional processing such as preliminary compaction, pre-compaction sintering or post-compaction sintering;   said impacting being performed by a powder compaction apparatus, comprising:   a power ram;   a crankshaft and spring system adapted to control power ram motion;   a die disposed in the path of said power ram;   a power feeder adapted to deliver powder to said die; and   a workpiece ejector adapted to eject a workpiece compacted from said powder.   
   
   
       15 . A method in accordance with  claim 14 , wherein said crankshaft and spring system are adapted to deliver a power stroke to said power ram following said controlled impact and prior to ejection of said workpiece. 
   
   
       16 . A method in accordance with  claim 14  wherein said power ram comprises a ram punch disposed in a punch middle part. 
   
   
       17 . A method in accordance with  claim 14  wherein said power ram is slidably disposed in punch holder. 
   
   
       18 . A method in accordance with  claim 14  wherein said power ram comprises one or more punch guiders. 
   
   
       19 . A method in accordance with  claim 14  wherein said power ram apparatus comprises a tool holder holding a tool outer and a tool inner that collectively comprise said die, said tool inner being supported by an anvil flush and an anvil plate. 
   
   
       20 . A method for compacting a powder material using high velocity adiabatic impact, comprising:
 impacting a quantity of powder material with a power ram at a controlled velocity in a single controlled impact on said powder material at a controlled specific impulse or specific kinetic energy to adiabatically compact said powder material into a workpiece with a relative density of 99% or above without additional processing such as preliminary compaction, pre-compaction sintering, post-compaction sintering, pre-heating of the powder material (warm compaction), lubrication or multiple impacts;   said power ram delivering a specific impulse of at least approximately 15-18 Newton-seconds/gram or a specific kinetic energy of least approximately 380-520 Joules/gram to said powder material;   said power ram velocity being at least approximately 30-50 meters/second when impacting said powder material; and   said method further comprising an additional ram power stroke applied following said single controlled impact and prior to ejection of said workpiece, said ram power stroke having a duration of up to approximately 100 milliseconds and a magnitude of up to approximately 2500 tons.