Mold core assembly and investment casting method

Abstract

The present invention discloses a mold core assembly. The mold core assembly includes at least one core. The core comprises a main body member and a high temperature-resistant material with a melting point over 1500° C., the length-diameter ratio of the main body member is greater than 50, and the main body member includes a high melting point metal with a melting point over 1500° C. The mold core assembly also includes a shell mold, wherein the shell mold encloses the core to form a cavity between the shell mold and the core, so as to accommodate a molten casting metal. The present invention further discloses an investment casting method.

What is claimed is: 
     
         1 . A mold-core assembly, comprising:
 at least one core comprising a main body with an aspect ratio of larger than 50 and comprising a high temperature resistant material with a melting point of higher than 1500 degree Celsius, the main body comprising a metal with a melting point of higher than 1500 degree Celsius; and   a shell mold surrounding the at least one core and spaced away from the at least one core to define a cavity for receiving molten base metal.   
     
     
         2 . The mold-core assembly of  claim 1 , wherein the main body comprises a matrix and a plurality of additives therein, the matrix comprises the metal and the plurality of additives comprise the high temperature resistant material. 
     
     
         3 . The mold-core assembly of  claim 1 , wherein the main body comprises a matrix and a plurality of additives therein, the matrix comprises the high temperature resistant material and the plurality of additives comprise the metal. 
     
     
         4 . The mold-core assembly of  claim 1 , wherein the at least one core further comprises a coating formed outside of the main body and comprising the high temperature resistant material. 
     
     
         5 . The mold-core assembly of  claim 1 , wherein the high temperature resistant material comprises at least one of quartz, ceramic, platinum group metals and cermet. 
     
     
         6 . The mold-core assembly of  claim 1 , wherein the main body comprises a tube comprising the metal, the at least one core further comprises a filler inside the tube, and the filler comprises the high temperature resistant material. 
     
     
         7 . The mold-core assembly of  claim 6 , wherein the filler comprises a plurality of powders filling in the tube. 
     
     
         8 . The mold-core assembly of  claim 6 , wherein the filler comprises a solid rod filling in and attached to the tube. 
     
     
         9 . The mold-core assembly of  claim 1 , wherein the metal of the main body comprises at least one of molybdenum, tungsten, titanium, platinum group metals, tantalum, chromium and niobium. 
     
     
         10 . The mold-core assembly of  claim 1 , wherein the main body of the at least one core comprises a cermet comprising the metal and a ceramic. 
     
     
         11 . The mold-core assembly of  claim 1 , wherein the main body comprises a non-round cross-section. 
     
     
         12 . The mold-core assembly of  claim 1 , wherein the main body comprises a non-straight shape. 
     
     
         13 . A method, comprising:
 forming at least one core comprising a main body with an aspect ratio of larger than 50 and comprising a high temperature resistant material with a melting point of higher than 1500 degree Celsius, the main body comprising a metal with a melting point of higher than 1500 degree Celsius;   forming a shell mold surrounding the at least one core and spaced away from the at least one core to define a cavity;   introducing molten base metal to the cavity to form a cast body; and   removing the shell mold.   
     
     
         14 . The method of  claim 13 , wherein the main body comprises a matrix and a plurality of additives therein, the matrix comprises the metal and the plurality of additives comprise the high temperature resistant material. 
     
     
         15 . The method of  claim 13 , wherein the main body comprises a matrix and a plurality of additives therein, the matrix comprises the high temperature resistant material and the plurality of additives comprise the metal. 
     
     
         16 . The method of  claim 13 , wherein forming the at least one core further comprises forming a coating outside of the main body, and the coating comprises the high temperature resistant material. 
     
     
         17 . The method of  claim 13 , wherein the main body comprises a tube comprising the metal, and forming the at least one core further comprising filling the tube with a filler comprising the high temperature resistant material. 
     
     
         18 . The method of  claim 13 , wherein the metal of the main body comprises at least one of molybdenum, tungsten, titanium, platinum group metals, tantalum, chromium and niobium. 
     
     
         19 . The method of  claim 13 , wherein the high temperature resistant material comprises at least one of quartz, ceramic, platinum group metals and cermet. 
     
     
         20 . The method of  claim 13 , wherein the main body of the at least one core comprises a cermet comprising the metal and a ceramic.