| 摘要 |
PURPOSE:To produce a low-oxygen target having a high density and large diameter with a simplified stage by forming tungsten powder by using a hot hydrostatic pressing method. CONSTITUTION:W powder contg. tungsten oxide is packed into a can for a hot hydrostatic press and while Ar or the like is admitted into the can, the oxidation of W by welding heat is prevented and an upper cap 4 is welded 6 thereto. High-purity hydrogen is kept admitted into and discharged from the can to fill the inside of the can with the flowing hydrogen and in this state the can is heated to about >=700 deg.C to reduce the tungsten oxide. The can of a bottom plate is sealed in this state and an inflow pipe is changed over with a vacuum evacuation device and after the inside of the can is evacuated to a high vacuum of about <=10<-4>Torr, the pipe is sealed. Such can is subjected to the hot hydrostatic pressing under about >=1,000kg/cm<2> gaseous pressure at about >=1,200 deg.C. The target consisting of the low-oxygen high melting metal such as W and having the high density and large diameter is obtd. by the above- mentioned method.
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