Method for Hot Isostatic Pressing

Abstract

A method for the treatment of metal articles by hot isostatic pressing, wherein air is used as the pressure medium for the hot isostatic pressing.

1 .- 11 . (canceled) 
   
   
       12 . A method for hot isostatic pressing of articles in a press, the press including a heat-insulated pressure vessel, a furnace chamber enclosed in the pressure vessel, and a load compartment arranged inside the furnace chamber, the method comprising:
 positioning articles to be pressed inside the load compartment, said articles being made of metal;   feeding pressure medium into the pressure vessel, said pressure medium being air;   increasing the temperature and the pressure in the load compartment;   maintaining the increased pressure and the increased temperature for a selected period of time; and   reducing the temperature and the pressure in the load compartment.   
   
   
       13 . The method as claimed in  claim 12 , wherein said air is ambient air. 
   
   
       14 . The method as claimed in  claim 12 , further comprising:
 storing pressurized ambient air in a gas storage; and   feeding said pressurized air from the gas storage into the pressure vessel as said pressure medium.   
   
   
       15 . The method as claimed in  claim 12 , further comprising:
 storing air in liquid form in a cryogenic storage; and   feeding said stored air from the cryogenic storage into the pressure vessel as said pressure medium.   
   
   
       16 . The method as claimed in  claim 12 , further comprising:
 dehumidifying the air to be used as said pressure medium.   
   
   
       17 . The method as claimed in  claim 12 , wherein, in increasing the pressure in the load compartment, the pressure is increased to 200-1000 bar. 
   
   
       18 . The method as claimed in  claim 17 , wherein, in increasing the pressure in the load compartment, the pressure is increased to 300-600 bar. 
   
   
       19 . The method as claimed in  claim 12 , wherein the temperature, in increasing the temperature in the load compartment, is increased to 400-600° C. 
   
   
       20 . The method as claimed in  claim 12 , wherein said metal is selected from the group of aluminium and aluminium alloys. 
   
   
       21 . A method of hot isostatic pressing of an article made of a metal, comprising:
 providing air as a pressure medium; and   using air as said pressure medium for the hot isostatic pressing.   
   
   
       22 . The method as claimed in  claim 21 , wherein said air is ambient air. 
   
   
       23 . The method as claimed in  claim 21 , wherein said metal is selected from the group of aluminium and aluminium alloys. 
   
   
       24 . The method as claimed in  claim 13 , further comprising the steps of:
 storing pressurized ambient air in a gas storage; and   feeding said pressurized air from the gas storage into the pressure vessel as said pressure medium.   
   
   
       25 . The method as claimed in  claim 13 , further comprising:
 storing air in liquid form in a cryogenic storage; and   feeding said stored air from the cryogenic storage into the pressure vessel as said pressure medium.   
   
   
       26 . The method as claimed in  claim 13 , further comprising:
 dehumidifying the air to be used as said pressure medium.   
   
   
       27 . The method as claimed in  claim 13 , wherein, in increasing the pressure in the load compartment, the pressure is increased to 200-1000 bar. 
   
   
       28 . The method as claimed in  claim 27 , wherein, in increasing the pressure in the load compartment, the pressure is increased to 300-600 bar. 
   
   
       29 . The method as claimed in  claim 13 , wherein the temperature, in increasing the temperature in the load compartment, is increased to 400-600° C. 
   
   
       30 . The method as claimed in  claim 13 , wherein said metal is selected from the group of aluminium and aluminium alloys. 
   
   
       31 . Method as claimed in  claim 22 , wherein said metal is selected from the group of aluminium and aluminium alloys.