Master alloy for casting a modified copper alloy and casting method using the same

Abstract

An advantage of the invention is to provide a master alloy used in a casting of a modified copper alloy, grains of which can be refined during a melt-solidification, and also a method of casting a modified copper alloy using the same. In order to achieve the advantage, master alloy for casting a copper alloy in a form of Cu: 40 to 80%, Zr: 0.5 to 35% and the balance of Zn; and Cu: 40 to 80%, Zr: 0.5 to 35%, P: 0.01 to 3% and the balance of Zn are used, and thus grain-refined copper alloy casting products are obtained.

1 - 13 . (canceled) 
     
     
         1 . A method of casting a modified copper alloy from a molten copper alloy containing Zr and P, the method comprising the steps of:
 providing a molten copper alloy including Cu: 40 to 80%, Zr: 0.5 to 35% and the balance of Zn;   adding at least Zr in the form of Cu—Zn—Zr or Cu—Zn—Zr—P alloy into said molten copper alloy; and   casting said molten copper alloy.   
     
     
         2 . The method of casting a modified copper alloy from a molten copper alloy containing Zr and P according to  claim 1 ,
 wherein Zr is added in the form of Cu—Zn—Zr—P alloy and concentration of the metal Zr in the molten alloy is in a range of 5 ppm or more in the presence of P when the molten copper alloy begins to solidify.   
     
     
         3 . The method of casting a modified copper alloy from a molten copper alloy containing Zr and P according to  claim 2 ,
 wherein the concentration of the metal Zr in the molten alloy is in a range of 20 to 500 ppm in the presence of P when the molten copper alloy begin to solidify.   
     
     
         4 . A master alloy for casting a copper alloy, comprising:
 Cu: 40 to 80%, Zr: 0.5 to 35% and the balance of Zn,   wherein when the master alloy is cast, the resulting copper alloy cast includes refined grain having a grain size of 50 μm or less,   wherein 0.2% proof strength of the resulting copper alloy cast is improved by 10% or more, comparing to a copper alloy cast obtained without grain refinement.   
     
     
         5 . A copper alloy cast obtained by using the master alloy comprising Cu: 40 to 80%, Zr: 0.5 to 35% and the balance of Zn,
 wherein the copper alloy cast includes refined grains having a grain size of 50 μm or less.