METHOD FOR MANUFACTURING METAL COMPOSITE THROUGH LIQUID METAL DEALLOYING USING MOLTEN Mg-Ca ALLOY AND Ti-BASED PRECURSOR ALLOY, AND METAL COMPOSITE MANUFACTURED THEREBY

Abstract

A method includes immersing a precursor alloy (Ti—X), which includes titanium (Ti) and a metal (X) that has miscibility with Ti and also with the melt and is thereby dissolved into the melt, into a melt containing magnesium (Mg) and calcium (Ca) to produce an Mg/Ti composite material. Since the Ca alloying element contained in the Mg—Ca alloy melt has high miscibility with Cu, it promotes the dealloying behavior in which Cu diffuses into the melt, thereby greatly shortening the process time required for fabricating the composite material. In addition, the Ca alloying element contained in the Mg—Ca alloy melt is dissolved in the Mg matrix, thereby increasing the volume fraction of the Mg matrix in the composite material, reducing the coarsening rate of Ti, and simultaneously improving the strength of the composite material through solid-solution strengthening of the Mg matrix.

1 . A method for manufacturing a metal composite material, comprising a step of immersing a precursor alloy (Ti—X), which includes titanium (Ti) and a metal (X) that has miscibility with Ti and is dissolved into a melt, into a melt containing magnesium (Mg) and calcium (Ca) to produce an Mg/Ti composite material. 
     
     
         2 . The method for manufacturing a metal composite material according to  claim 1 , wherein the melt contains 10 wt % or less of calcium (Ca). 
     
     
         3 . The method for manufacturing a metal composite material according to  claim 1 ,
 wherein the precursor alloy is selected from the group consisting of a Ti—Cu alloy, Ti—Ni alloy, Ti—Zn alloy, Ti—Ga alloy, Ti—Ge alloy, Ti—As alloy, Ti—Rh alloy, Ti—Pd alloy, Ti—Ag alloy, Ti—Cd alloy, Ti—In alloy, Ti—Sn alloy, Ti—Sb alloy, Ti—Ir alloy, Ti—Pt alloy, Ti—Au alloy, Ti—Hg alloy, Ti—Pb alloy, and Ti—Bi alloy.   
     
     
         4 . The method for manufacturing a metal composite material according to  claim 1 ,
 wherein a Ti—Cu alloy is immersed in a melt containing magnesium (Mg) and calcium (Ca), copper being dissolved into the melt, and the melt being filled into voids formed in the precursor alloy due to the dissolution of copper, thereby forming the Mg/Ti composite material.   
     
     
         5 . The method for manufacturing a metal composite material according to  claim 4 , comprising a step of immersing a precursor alloy (Ti 30 Cu 70 ), which includes titanium (Ti) and copper (Cu) at an atomic ratio of 30:70, into an Mg-1 wt % Ca melt composed of 99 wt % magnesium (Mg) and 1 wt % calcium (Ca) for 10 minutes or less to produce the Mg/Ti composite material. 
     
     
         6 . The method for manufacturing a metal composite material according to  claim 1 , comprising:
 (a) immersing a precursor alloy (Ti—X), which includes titanium (Ti) and a metal (X) that has miscibility with Ti and also with the melt and is thereby dissolved into the melt, into a melt containing magnesium (Mg) and calcium (Ca) to produce an Mg/Ti composite material;   (b) producing a titanium (Ti) porous structure from the Mg/Ti composite material; and   (c) immersing the titanium (Ti) porous structure into an Mg—Al alloy melt to produce an Mg/TiAl composite material.   
     
     
         7 . The method for manufacturing a metal composite material according to  claim 6 ,
 wherein, in step (b), the Mg/Ti composite material is immersed in an acid solution to remove magnesium or a magnesium alloy from the Mg/Ti composite material, thereby producing the titanium (Ti) porous structure.   
     
     
         8 . The method for manufacturing a metal composite material according to  claim 6 ,
 wherein, in step (c), the titanium (Ti) porous structure is immersed in an Mg-3 wt % Al alloy melt to produce the Mg/TiAl composite material.   
     
     
         9 . The method for manufacturing a metal composite material according to  claim 6 , comprising:
 (a) immersing a precursor alloy (Ti 30 Cu 70 ), which includes titanium (Ti) and copper (Cu) at an atomic ratio of 30:70, into a melt containing magnesium (Mg) and calcium (Ca) to produce an Mg/Ti composite material;   (b) immersing the Mg/Ti composite material in an aqueous nitric acid (HNO 3 ) solution to remove magnesium or a magnesium alloy from the Mg/Ti composite material, thereby producing a titanium (Ti) porous structure; and   (c) immersing the titanium (Ti) porous structure in an Mg-3 wt % Al alloy melt for 10 seconds to 2 hours to produce an Mg/TiAl composite material.   
     
     
         10 . A metal composite material manufactured by the method according to  claim 1 .