Expandable core for use in casting

Abstract

A salt core ( 2 ) is formed by casting a mixed material of a salt material and a ceramic material. Any one of a chloride, bromide, carbonate, and sulfate of potassium or sodium is used as the salt material. As the ceramic material, granular one having a density falling within a range of 2.2 g/cm 3 (exclusive) to 4 g/cm 3 (inclusive) is used.

1 . A core for use in casting which is formed by casting a mixed material of a salt material and a ceramic material, said salt material comprising any one of a chloride, a bromide, a carbonate, and a sulfate of any one of potassium and sodium, and said ceramic material comprising artificially synthesized granular one having a density falling within a range of 2.2 g/cm 3  (exclusive) to 4 g/cm 3  (inclusive).  
   
   
       2 . A core for use in casting according to  claim 1 , wherein said ceramic material comprises synthetic mullite having a density of 2.79 g/cm 3  to 3.15 g/cm 3 .  
   
   
       3 . A core for use in casting according to  claim 1 , wherein said ceramic material comprises aluminum borate having a density of 2.93 g/cm 3 .  
   
   
       4 . A core for use in casting which is formed by casting a mixed material of a salt material and a ceramic material, said salt material comprising any one of a chloride, a bromide, a carbonate, and a sulfate of any one of potassium and sodium, and said ceramic material comprising artificially synthesized granular one having a particle size of not more than 150 μm.  
   
   
       5 . A core for use in casting which is formed by casting a mixed material of a salt material and a ceramic material, said salt material comprising any one of a chloride, a bromide, a carbonate, and a sulfate of any one of potassium and sodium, and said ceramic material comprising any granular one of synthetic mullite, aluminum borate, boron carbide, silicon nitride, silicon carbide, aluminum nitride, aluminum titanate, cordierite, and alumina.  
   
   
       6 . A core for use in casting which is formed by casting a mixed material of a salt material and a ceramic material, said salt material comprising any one of a chloride, a bromide, a carbonate, and a sulfate of any one of potassium and sodium, and said ceramic material comprising whiskers of any one of aluminum borate, silicon nitride, silicon carbide, potassium hexatitanate, potassium octatitanate, and zinc oxide.  
   
   
       7 . A core for use in casting according to  claim 6 , wherein said ceramic material comprises aluminum borate whiskers.  
   
   
       8 . A core for use in casting which is formed by casting a mixed material of a salt material and a ceramic material, said salt material comprising a mixed salt obtained by adding any one of a carbonate and a sulfate of any one of potassium and sodium to a chloride of any one of potassium and sodium, and said ceramic material comprising artificially synthesized granular one having a density falling within a range of 2.2 g/cm 3  (exclusive) to 4 g/cm 3  (inclusive).  
   
   
       9 . A core for use in casting according to  claim 8 , wherein said ceramic material comprises synthetic mullite having a density falling in a range of 2.79 g/cm 3  to 3.15 g/cm 3 .  
   
   
       10 . A core for use in casting according to  claim 8 , wherein said ceramic material comprises aluminum borate having a density of 2.93 g/cm 3 .  
   
   
       11 . A core for use in casting which is formed by casting a mixed material of a salt material and a ceramic material, said salt material comprising a mixed salt obtained by adding any one of a carbonate and a sulfate of any one of potassium and sodium to a chloride of any one of potassium and sodium, and said ceramic material comprising artificially synthesized granular one having a particle size of not more than 150 μm.  
   
   
       12 . A core for use in casting which is formed by casting a mixed material of a salt material and a ceramic material, said salt material comprising a mixed salt obtained by adding any one of a carbonate and a sulfate of any one of potassium and sodium to a chloride of any one of potassium and sodium, and said ceramic material comprising any granular one of synthetic mullite, aluminum borate, boron carbide, silicon nitride, silicon carbide, aluminum nitride, aluminum titanate, cordierite, and alumina.  
   
   
       13 . A core for use in casting which is formed by casting a mixed material of a salt material and a ceramic material, said salt material comprising a mixed salt obtained by adding any one of a carbonate and a sulfate of any one of potassium and sodium to a chloride of any one of potassium and sodium, and said ceramic material comprising whiskers of any one of aluminum borate, silicon nitride, silicon carbide, potassium hexatitanate, potassium octatitanate, and zinc oxide.  
   
   
       14 . A core for use in casting according to  claim 13 , wherein said ceramic material comprises aluminum borate whiskers.  
   
   
       15 . A core for use in casting according to any one of  claims 8  to  14 , wherein said mixed salt is made from potassium chloride and sodium carbonate.