Article With Grouped Grain Patterns

Abstract

An article includes a first portion having a first grain pattern and a second portion having a second grain pattern different from the first grain pattern. The article is a cast article such as a turbine engine blade.

What is claimed is: 
     
         1 . An article comprising:
 a first portion having a first grain pattern; and   a second portion having a second grain pattern different from said first grain pattern.   
     
     
         2 . The article of  claim 1  wherein said first grain pattern is an equiaxed grain pattern. 
     
     
         3 . The article of  claim 2 , wherein said first portion is a root attachment section. 
     
     
         4 . The article of  claim 1 , wherein said second grain pattern is a directionally solidified pattern. 
     
     
         5 . The article of  claim 4 , wherein said second portion is an airfoil portion. 
     
     
         6 . The article of  claim 1 , wherein said article is a turbine engine blade. 
     
     
         7 . The article of  claim 1 , wherein said article is a cast article. 
     
     
         8 . A method for forming an article comprising:
 providing a mold; and   casting a metal material within said mold so that a part is produced which has a first portion having a first grain pattern and a second portion having a second grain pattern different from said first grain pattern.   
     
     
         9 . The method according to  claim 8 , further comprising:
 forming said mold using a wax pattern and dipping the wax pattern into a ceramic material.   
     
     
         10 . The method according to  claim 9 , further comprising:
 applying a cobalt containing material to a surface of said wax pattern prior to said dipping step.   
     
     
         11 . The method according to  claim 10 , wherein said cobalt containing material applying step comprises applying a material selected from the group consisting of 7% cobalt aluminate and cobalt oxide. 
     
     
         12 . The method according to  claim 8 , further comprising placing a shield around said mold. 
     
     
         13 . The method according to  claim 12 , wherein said placing step comprises placing a shield which extends from a first region of the mold where a root attachment section will be formed to a second region of the mold where a platform will be formed. 
     
     
         14 . The method according to  claim 12 , further comprising:
 providing a scepter and a controller for said scepter;   programming said controller to have a grouped grain program profile; and   powering said scepter after said metal material in molten form has been placed into said mold to form said part having said first grain pattern and said second grain pattern.   
     
     
         15 . The method of  claim 8  wherein casting step comprises forming said first grain pattern as an equiaxed grain pattern. 
     
     
         16 . The method of  claim 15 , wherein said casting step further comprises forming said equiaxed grain pattern in a root attachment section. 
     
     
         17 . The method of  claim 15 , wherein said casting step comprises forming said second grain pattern as a directionally solidified pattern. 
     
     
         18 . The method of  claim 17 , wherein said casting step further comprises forming said second pattern in an airfoil portion. 
     
     
         19 . A casting system for forming a part having a first portion with a first grain pattern and a second portion with a second grain pattern different from the first grain pattern, said casting system comprising:
 a mold having a length; and   a shield having a length less than the length of the mold.   
     
     
         20 . The casting system of  claim 19 , further comprising a scepter surrounding said mold and a controller for said scepter. 
     
     
         21 . The casting system of  claim 20 , wherein said controller is programmed to have a grouped grain program profile.