Process for producing spherical titanium alloy powder

Abstract

In production of a titanium alloy spherical powder by a gas atomizing method, the difference in alloy composition depending on the product particle size is reduced economically. To achieve this, sponge titanium particles and additive metal element particles are mixed by means of a mixer having a pulverizing function such as a ball mill. The mixed particles are compressed to form a rod-formed raw material for melting. The formed rod-formed raw material for melting is powderized by a gas atomizing method. In the mixing step, the additive metal element particles are pulverized, or ground depending on the kind of particles, and solidly adhered to the surface of the sponge titanium particles, so that uniform mixing is possible.

1 . A process for producing a titanium alloy spherical powder comprising the steps of:
 mixing sponge titanium particles and additive metal element particles by means of a mixer having a pulverizing function;   compressing mixed particles obtained by mixing by the mixer to form a rod-formed raw material for melting;   induction-heating the formed rod-formed raw material for melting in an inert atmosphere to melt it in a non-contact manner; and   powderizing an alloy melt obtained by non-contact melting by a gas atomizing method.   
   
   
       2 . The process for producing a titanium alloy spherical powder according to  claim 1 , wherein said additive metal element powder is a master alloy obtained by smelting a plurality of metal elements. 
   
   
       3 . The process for producing a titanium alloy spherical powder according to  claim 2 , wherein said master alloy is AlV (Al:V=6:4), and a Ti-6Al-4V spherical powder is produced using the same. 
   
   
       4 . The process for producing a titanium alloy spherical powder according to  claim 1 , wherein said sponge titanium particles have an average particle size of 0.3 to 5 mm. 
   
   
       5 . The process for producing a titanium alloy spherical powder according to  claim 1 , wherein said sponge titanium particles are sub-sieve materials derived in a refining and classifying step of sponge titanium for expanded materials. 
   
   
       6 . The process for producing a titanium alloy spherical powder according to  claim 1 , wherein said mixer is a ball mill, an attritor or a vibration mill. 
   
   
       7 . The process for producing a titanium alloy spherical powder according to  claim 1 , wherein said additive metal element powder has an average particle size of 0.2 to 50 mm.