Method of producing target material of Mo alloy

Abstract

Disclosed is a method of producing a target material of a Mo alloy, which includes the steps of (a) preparing a green compact by compressing a raw material powder blend consisting of a Mo powder having an average particle size of not more than 20 μm and a transition metal powder having an average particle size of not more than 500 μm; (b) pulverizing the green compact to produce a secondary powder having an average particle size of from not less than an average particle size of the raw material powder blend to not more than 10 mm; (c) filling the secondary powder into a container for pressurizing; and (d) subjecting the secondary powder with the container for pressurizing to sintering under pressure thereby obtaining a sintered body of the target material.

1 . A method of producing a target material of a Mo alloy, which comprises the steps of: 
 (a) preparing a green compact by compressing a raw material powder blend consisting of a Mo powder having an average particle size of not more than 20 μm and a transition metal powder having an average particle size of not more than 500 μm;    (b) pulverizing the green compact to produce a secondary powder having an average particle size of from not less than an average particle size of the raw material powder blend to not more than 10 mm;    (c) filling the secondary powder into a container for pressurizing; and    (d) subjecting the secondary powder with the container for pressurizing to sintering under pressure thereby obtaining a sintered body of the target material.    
     
     
         2 . A method according to  claim 1 , wherein the transition metal is any one selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr and W.  
     
     
         3 . A method according to  claim 1 , wherein after the sintering process (d), the sintered body being enveloped in the container is subjected to hot plastic working.  
     
     
         4 . A method according to  claim 1 , wherein the hot plastic working is of plural times of plastic working under the conditions of a reduction ratio of 2 to 50% and a temperature of 500 to 1500° C.  
     
     
         5 . A method according to  claim 1 , wherein after the step (d), the sintered body being enveloped in the container is subjected to hot plastic working followed by recrystallization heat treatment.  
     
     
         6 . A method according to  claim 5 , wherein the hot plastic working is of plural times of plastic working under the conditions of a reduction ratio of 2 to 50% and a temperature of 500 to 1500° C.  
     
     
         7 . A method according to  claim 6 , wherein the recrystallization heat treatment is carried out at a temperature of 1000 to 1500° C.  
     
     
         8 . A method according to  claim 1 , wherein the compression process in the step (a) is carried out by cold isostatic pressing under a pressure of not less than 100 MPa.  
     
     
         9 . A method according to  claim 1 , wherein the sintering process in the sintering process (d) is carried out by hot isostatic pressing at a temperature of 1000 to 1500° C. under a pressure of not less than 100 MPa.  
     
     
         10 . A method according to  claim 1 , wherein the container filled with the secondary powder is of a metal capsule having a substantially rectangular parallelepiped form one of which face is used as an inlet opening for filling the secondary powder, the face being opposite to a bottom wall of the container forming the maximum depth, and which inner space has a maximum length of not less than 1000 mm.  
     
     
         11 . A method according to  claim 10 , wherein the sintered body is sliced to obtain a plurality of tabular targets so as to maintain a maximum side length of the sintered body.