Method of and apparatus for manufacturing joined body

Abstract

Electrodes are embedded respectively in a first die and a second die. A metal workpiece is placed in a cavity defined between the first die and the second die which mate with each other. Then, a molten metal is poured through a passage into the cavity. The molten metal is solidified into a casting, forming a contact region of the metal workpiece and the casting. Thereafter, an electric current is supplied from a power supply between the electrodes across the contact region. The supplied electric current breaks an oxide film that is present on the surface of the metal workpiece, and joins the metal workpiece and the casting in the contact region.

1 . A method of manufacturing a joined body having a metal workpiece and a casting which are joined to each other, comprising the steps of: 
 placing the metal workpiece in a cavity defined between a first die and a second die with electrodes disposed on respective molding surfaces thereof;    pouring a molten metal into said cavity to form a contact region of said molten metal and said metal workpiece or a contact region of a casting produced when the molten metal is solidified or semi-solidified and said metal workpiece, between the electrode on said first die and the electrode on said second die; and    supplying an electric current between said electrodes to join said contact region to produce a joined body.    
   
   
       2 . A method according to  claim 1 , further comprising the step of 
 before said molten metal is poured into said cavity, pressing said metal workpiece between said first die and said second die.    
   
   
       3 . A method according to  claim 1 , wherein said electrodes are made of a material having a resistivity value higher than those of said metal workpiece and said casting and a melting point higher than the boiling point of said metal workpiece and the boiling point of said casting.  
   
   
       4 . A method according to  claim 1 , wherein said metal workpiece has an oxide film on a surface thereof.  
   
   
       5 . A method according to  claim 4 , wherein the electric current is supplied to said electrodes for flowing the electric current transversely across said oxide film.  
   
   
       6 . An apparatus for manufacturing a joined body having a metal workpiece and a casting which are joined to each other, comprising: 
 a first die and a second die with electrodes disposed on respective molding surfaces thereof;    a power supply electrically connected to the electrode on said first die and the electrode on said second die; and    a passage for introducing a molten metal into a cavity defined between said first die and said second die.    
   
   
       7 . An apparatus according to  claim 6 , wherein said first die and said second die double as dies for pressing said metal workpiece.  
   
   
       8 . An apparatus according to  claim 6 , wherein said electrodes are made of a material having a resistivity value higher than those of said metal workpiece and said casting and a melting point higher than the boiling point of said metal workpiece and the boiling point of said casting.  
   
   
       9 . An apparatus according to  claim 6 , wherein said metal workpiece has an oxide film on a surface thereof.  
   
   
       10 . An apparatus according to  claim 9 , wherein said electrodes are disposed in respective positions for supplying an electric current transversely across said oxide film.  
   
   
       11 . A method of manufacturing a joined body having a first member and a second member which are joined to each other, comprising the steps of: 
 placing the first member in a cavity defined between dies;    pouring a molten metal into the cavity for forming the second member; and    supplying an electric current between the first member and the second member.    
   
   
       12 . A method according to  claim 11 , wherein an electric current is supplied between the first and second members in the dies.  
   
   
       13 . An apparatus for manufacturing a joined body having a first member and a second member which are joined to each other, comprising: 
 dies having a housing section for housing the first member and a molding section for forming the second member; and    a power supply electrically connected to the dies.    
   
   
       14 . An apparatus according to  claim 13 , wherein the power supply is electrically connected such that an electric current flows through the housing section and the molding section.