Method for producing metal formed article

Abstract

There is disclosed a method for producing a metal formed article having a space in the interior thereof, comprising the steps of laying a formed article 2 a of a second metal in a powder 1 containing a first metal to thereby form a powder formed article 3 a and heating and melting the formed article 2 a at a temperature less than a melting point of the first metal and not less than that of the second metal to form a space 4 . Both the metals are sintered and solidified. A coating layer 6 is formed on the space 4 by an intermetallic compound or an alloy of both the metals. When the coating layer 6 is the intermetallic compound, the first metal is one type of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Hf, Ta, and W and an alloy of these elements, and the second metal is Al. The first metal is Ti, V, Cr, Fe, Co, Ni, Zr, Nb, Mo, Hf, Ta, and W and an alloy of these elements, and the second metal is Si. The first metal is Cu or an alloy thereof, and the second metal is Sn. When the coating layer 6 is the alloy, the first metal is Al or an alloy thereof, and the second metal is Zn.

1 . A method for producing a metal formed article, comprising the steps of: 
 burying a formed article comprising a second metal whose melting point is lower than that of the first metal in a powder containing a first metal, and forming a powder formed article containing the formed article; and    heating the powder formed article at a temperature lower than the melting point of the first metal and higher than the melting point of the second metal, melting the second metal, allowing the molten second metal to move into voids in the powder containing the first metal, forming a space in a region which has been occupied by the formed article comprising the second metal, and sintering and solidifying the powder of the first metal and the molten second metal.    
     
     
         2 . The method for producing the metal formed article according to  claim 1 , comprising the step of forming a coating layer to coat the surface of the space formed in the region which has been occupied by the second metal by an intermetallic compound formed of the first and second metals.  
     
     
         3 . The method for producing the metal formed article according to  claim 2 , wherein the first metal is one type of metal selected from a group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Hf, Ta, and W and an alloy of these elements, and the second metal is Al.  
     
     
         4 . The method for producing the metal formed article according to  claim 2 , wherein the first metal is one type of metal selected from a group consisting of Ti, V, Cr, Fe, Co, Ni, Zr, Nb, Mo, Hf, Ta, and W and an alloy of these elements, and the second metal is Si.  
     
     
         5 . The method for producing the metal formed article according to  claim 2 , wherein the first metal is Cu or an alloy thereof, and a second metal is Sn.  
     
     
         6 . The method for producing the metal formed article according to  claim 1 , comprising the step of forming a coating layer to coat the surface of the space formed in the region which has been occupied by the second metal by an alloy formed of the first and second metals.  
     
     
         7 . The method for producing the metal formed article according to  claim 6 , wherein the first metal is Al or an alloy thereof, and the second metal is Zn or an alloy thereof.  
     
     
         8 . The method for producing the metal formed article according to any one of  claims 1  to  7 , wherein the powder formed article is heated to at least a melting point of the second metal at a temperature rising rate of 1 kelvin/second or more.