Mixed powder for powder metallurgy

Abstract

An objective of the present invention is to provide a mixed powder for powder metallurgy that makes it possible to improve mold-filling ability and reduce spread in weight of molded bodies. The mixed powder for powder metallurgy according to the present invention is obtained by mixing a graphite powder with an average particle diameter D50 of 1.0 μm or more to 3.0 μm or less and D90 of 10 μm or less, without adding a binder, with an iron-based powder, while applying a sheer force. The thus obtained mixed powder for powder metallurgy according to the present invention is characterized by including the iron-based powder and the graphite powder present so as to be collected in concave portions of the iron-based powder.

1 . A mixed powder, obtained by a process comprising
 mixing a graphite powder with an average particle diameter D50 of 1.0 μm or more to 3.0 μm or less and D90 of 10 μm or less and an iron-based powder   without adding a binder   while applying a sheer force.   
     
     
         2 . A mixed powder, comprising
 an iron-based powder and   a graphite powder present so as to be collected in concave portions of the iron-based powder.   
     
     
         3 . The mixed powder according to  claim 1 , wherein the average particle diameter D50 of the graphite powder is 1.6 μm or more to 2.7 μm or less. 
     
     
         4 . The mixed powder according to  claim 1 , wherein the iron-based powder is an atomized iron powder or reduced iron powder. 
     
     
         5 . The mixed powder according to  claim 2 , wherein the iron-based powder is an atomized iron powder or reduced iron powder. 
     
     
         6 . The mixed powder according to  claim 3 , wherein the iron-based powder is an atomized iron powder or reduced iron powder.