Die casting method and apparatus for rheocasting

Abstract

Provided are a die casting method and apparatus for rheocasting that ensure the manufacture of products with a fine, uniform, spherical particle structure, with improvements in energy efficiency and mechanical properties, cost reduction, convenience of casting, and shorter manufacturing time. The die casting method involves applying an electromagnetic field to a slurry manufacturing domain in a sleeve having an end through which a plunger is inserted and the other end connected to a casting die with a mold cavity, loading a molten metal into the slurry manufacturing domain to manufacture a semi-solid metallic slurry, and moving the plunger toward the casting die to push the metallic slurry into the mold cavity.

What is claimed is:  
     
         1 . A die casting method for rheocasting, the method comprising: 
 applying an electromagnetic field to a slurry manufacturing domain in a sleeve having an end through which a plunger is inserted and the other end connected to a casting die with a mold cavity and loading a molten metal into the slurry manufacturing domain to manufacture a semi-solid metallic slurry; and    moving the plunger toward the casting die to push the metallic slurry into the mold cavity.    
     
     
         2 . The die casting method of  claim 1 , wherein the sleeve is horizontally positioned, and the slurry manufacturing domain is defined by a door installed near the other end of the sleeve and the plunger inserted through the end of the sleeve.  
     
     
         3 . The die casting method of  claim 1 , wherein the sleeve is inclined such that the end through which the plunger is inserted faces downward, and the slurry manufacturing domain is defined by only the plunger inserted through one end of the sleeve.  
     
     
         4 . The die casting method of  claim 1 , wherein at least a portion of the sleeve is inclined at an angle such that the end through which the plunger is inserted faces downward, and the slurry manufacturing domain is defined by only the plunger inserted through one end of the sleeve.  
     
     
         5 . The die casting method of  claim 1 , wherein the sleeve is vertically positioned such that the end through which the plunger is inserted faces downward, and the slurry manufacturing domain is defined by only the plunger inserted through one end of the sleeve.  
     
     
         6 . The die casting method of any one of claims  1  through  5 , wherein applying the electromagnetic field to the slurry manufacturing domain is performed prior to loading the molten metal into the sleeve.  
     
     
         7 . The die casting method of any one of claims  1  through  5 , wherein applying the electromagnetic field to the slurry manufacturing domain is performed at the start of loading the molten metal into the sleeve.  
     
     
         8 . The die casting method of any one of claims  1  through  5 , wherein applying the electromagnetic field to the slurry manufacturing domain is performed in the middle of loading the molten metal into the sleeve.  
     
     
         9 . The die casting method of any one of claims  1  through  5 , wherein applying the electromagnetic field to the sleeve is sustained until the molten metal in the slurry manufacturing domain has a solid fraction of 0.001-0.7.  
     
     
         10 . The die casting method of  claim 9 , wherein applying the electromagnetic field to the sleeve is sustained until the molten metal in the slurry manufacturing domain has a solid fraction of 0.001-0.4.  
     
     
         11 . The die casting method of  claim 10 , wherein applying the electromagnetic field to the sleeve is sustained until the molten metal in the slurry manufacturing domain has a solid fraction of 0.001-0.1.  
     
     
         12 . The die casting method of any one of claims  1  through  5 , further comprising cooling the molten metal loaded into the slurry manufacturing domain under the electromagnetic field.  
     
     
         13 . The die casting method of  claim 12 , wherein cooling the molten metal is sustained until the molten metal in the slurry manufacturing domain has a solid fraction of 0.1-0.7.  
     
     
         14 . The die casting method of  claim 12 , wherein cooling the molten metal is performed at a rate of 0.2-5.0/sec.  
     
     
         15 . The die casting method of  claim 14 , wherein cooling the molten metal is performed at a rate of 0.2-2.0/sec.  
     
     
         16 . A die casting apparatus for rheocasting, the apparatus comprising: 
 a stirring unit which includes a space and applies an electromagnetic field to the space;    a sleeve which is accommodated in the space of the stirring unit and into which a molten metal is loaded;    a plunger which is inserted through an end of the sleeve to push a semi-solid slurry manufactured in the sleeve; and    a casting die connected to the other end of the sleeve, the casting die including a movable die and a fixed die which form a mold cavity when combined together and casting a product from the slurry pushed into the mold cavity by the plunger.    
     
     
         17 . The die casting apparatus of  claim 16 , wherein the sleeve is horizontally positioned, and a door is further installed close to the other end of the sleeve connected to the casting die so as to close a through hole of the casting die during the manufacture of the slurry and to open the through hole when the manufactured slurry is pushed toward the casting die by the plunger.  
     
     
         18 . The die casting apparatus of  claim 16 , wherein at least a portion of the sleeve is inclined at an angle such that the end of the sleeve through which the plunger is inserted faces downward.  
     
     
         19 . The die casting apparatus of  claim 16 , wherein the sleeve comprises a first sleeve having the end through which the plunger is inserted and being able to pivot downward and a second sleeve horizontally positioned, and the first sleeve can be positioned at an angel to be placed in the space of the stirring unit and can be positioned to be aligned with the second sleeve.  
     
     
         20 . The die casting apparatus of  claim 16 , wherein the sleeve is vertically arranged to direct the end through which the plunger is inserted downward, is movable up and down, and is raised together with the plunger after the manufacture of the slurry to couple to the casting die and allow the plunger to push the manufactured slurry into the mold cavity of the casting die.  
     
     
         21 . The die casting apparatus of  claim 16 , wherein the stirring unit applies the electromagnetic field prior to loading the molten metal into the sleeve.  
     
     
         22 . The die casting apparatus of  claim 16 , wherein the stirring unit applies the electromagnetic field at the start of loading the molten metal into the sleeve.  
     
     
         23 . The die casting apparatus of  claim 16 , wherein the stirring unit applies the electromagnetic field in the middle of loading the molten metal into the sleeve.  
     
     
         24 . The die casting apparatus of  claim 16 , wherein the stirring unit applies the electromagnetic file until the molten metal in the sleeve has a solid fraction of 0.001-0.7.  
     
     
         25 . The die casting apparatus of  claim 24 , wherein the stirring unit applies the electromagnetic field until the molten metal in the sleeve has a solid fraction of 0.001-0.4.  
     
     
         26 . The die casting apparatus of  claim 25 , wherein the stirring unit applies the electromagnetic field until the molten metal in the sleeve has a solid fraction of 0.001-0.1.  
     
     
         27 . The die casting apparatus of  claim 20 , wherein the sleeve comprises a temperature control element.  
     
     
         28 . The die casting apparatus of  claim 27 , wherein the temperature control element comprises at least one of a cooler and an electrical heater.  
     
     
         29 . The die casting apparatus of  claim 27 , wherein the temperature control element cools the molten metal in the sleeve to reach a solid fraction of 0.1-0.7.  
     
     
         30 . The die casting apparatus of  claim 27 , wherein the temperature control element cools the molten metal in the sleeve at a rate of 0.2-5.0/sec.  
     
     
         31 . The die casting apparatus of  claim 30 , wherein the temperature control element controls the molten metal in the sleeve at a rate of 0.2-2.0/sec.