Method and assembly for forming components having internal passages using a lattice structure

Abstract

A mold assembly for use in forming a component having a first internal passage defined therein includes a mold that defines a mold cavity therein. The mold assembly also includes a lattice structure selectively positioned at least partially within the mold cavity and formed from a first material. The first material is at least partially absorbable by a component material in a molten state. The mold assembly further includes a first segmented core that includes at least one joint segment coupled to the lattice structure. The at least one joint segment is coupled in serial flow communication to at least one extension segment such that a first hollow structure is defined. A first inner core is disposed within the first hollow structure such that at least a portion of the first inner core defines the first internal passage when the component is formed in the mold assembly.

What is claimed is: 
     
         1 . A mold assembly for use in forming a component having a first internal passage defined therein, the component formed from a component material, said mold assembly comprising:
 a mold defining a mold cavity therein;   a lattice structure selectively positioned at least partially within said mold cavity, said lattice structure formed from a first material that is at least partially absorbable by the component material in a molten state; and   a first segmented core comprising at least one joint segment coupled to said lattice structure, said at least one joint segment of said first segmented core coupled in serial flow communication to at least one extension segment such that a first hollow structure is defined, wherein a first inner core is disposed within said first hollow structure such that at least a portion of said first inner core defines the first internal passage when the component is formed in said mold assembly.   
     
     
         2 . The mold assembly of  claim 1 , wherein said mold comprises an interior wall that defines said mold cavity and said lattice structure defines a perimeter, said lattice structure is selectively positioned within said mold cavity by said perimeter coupled against said interior wall. 
     
     
         3 . The mold assembly of  claim 1 , wherein the component has a second internal passage defined therein, said mold assembly further comprising a second segmented core comprising at least one joint segment coupled to said lattice structure, said at least one joint segment of said second segmented core coupled in serial flow communication to at least one extension segment of said second segmented core such that a second hollow structure is defined, wherein a second inner core is disposed within said second hollow structure such that at least a portion of said second inner core defines the second internal passage when the component is formed in said mold assembly. 
     
     
         4 . The mold assembly of  claim 1 , wherein said lattice structure comprises a plurality of sectional elongated members, each said at least one joint segment is coupled to a corresponding group of said sectional elongated members. 
     
     
         5 . The mold assembly of  claim 4 , wherein each said joint segment is formed integrally with said corresponding group of sectional elongated members by an additive manufacturing process. 
     
     
         6 . The mold assembly of  claim 1 , wherein an inner wall of said at least one extension segment has a relatively low surface roughness as compared to an inner wall of said at least one joint segment. 
     
     
         7 . The mold assembly of  claim 1 , wherein a longitudinal position of said at least one joint segment corresponds to a region of relatively high curvature of said hollow structure. 
     
     
         8 . The mold assembly of  claim 1 , wherein a longitudinal position of said at least one joint segment corresponds to a region at which said first hollow structure defines a change in a cross-sectional flow area of the first internal passage. 
     
     
         9 . The mold assembly of  claim 1 , wherein a longitudinal position of said at least one joint segment corresponds to a region at which structural support from said lattice structure facilitates stabilization of a position of said first segmented core. 
     
     
         10 . The mold assembly of  claim 1 , wherein said at least one extension segment is formed from at least one extruded tube segment. 
     
     
         11 . The mold assembly of  claim 1 , wherein said first material is at least partially absorbable by the component material in a molten state such that a performance of the component material in a solid state is not degraded. 
     
     
         12 . The mold assembly of  claim 9 , wherein the component material is an alloy, and said first material comprises at least one constituent material of the alloy. 
     
     
         13 . The mold assembly of  claim 1 , wherein said at least one joint segment and said at least one extension segment are coupled together by at least one of an externally flush joint, a diverging joint, and a converging joint. 
     
     
         14 . A method of forming a component having a first internal passage defined therein, said method comprising:
 selectively positioning a lattice structure at least partially within a cavity of a mold, wherein:
 the lattice structure is formed from a first material, 
 at least one joint segment of a first segmented core is coupled to the lattice structure, 
 the at least one joint segment of the first segmented core is coupled in serial flow communication to at least one extension segment of the first segmented core such that a first hollow structure is defined, and 
 a first inner core is disposed within the first hollow structure; 
   introducing a component material in a molten state into the cavity, such that the component material in the molten state at least partially absorbs the first material from the lattice structure; and   cooling the component material in the cavity to form the component, wherein at least a portion of the first inner core defines the first internal passage within the component.   
     
     
         15 . The method of  claim 14 , wherein the mold includes an interior wall that defines the cavity and the lattice structure defines a perimeter, said selectively positioning the lattice structure comprises coupling the perimeter of the lattice structure against the interior wall of the mold. 
     
     
         16 . The method of  claim 14 , wherein at least one joint segment of a second segmented core is coupled to the lattice structure, the at least one joint segment of the second segmented core is coupled in serial flow communication to at least one extension segment of the second segmented core such that a second hollow structure is defined, and a second inner core is disposed within the second hollow structure, said cooling the component material in the cavity to form the component further comprises cooling the component material in the cavity wherein at least a portion of the second inner core defines a second internal passage within the component. 
     
     
         17 . The method of  claim 14 , wherein said selectively positioning the lattice structure comprises selectively positioning the lattice structure that includes a plurality of sectional elongated members, each at least one joint segment is coupled to a corresponding group of the sectional elongated members. 
     
     
         18 . The method of  claim 17 , wherein said selectively positioning the lattice structure comprises selectively positioning the lattice structure that includes each at least one joint segment formed integrally with the corresponding group of sectional elongated members by an additive manufacturing process. 
     
     
         19 . The method of  claim 14 , wherein said selectively positioning the lattice structure comprises selectively positioning the lattice structure wherein an inner wall of the at least one extension segment has a relatively low surface roughness as compared to an inner wall of the at least one joint segment. 
     
     
         20 . The method of  claim 14 , wherein said selectively positioning the lattice structure comprises selectively positioning the lattice structure wherein a longitudinal position of the at least one joint segment corresponds to a region of relatively high curvature of the first hollow structure. 
     
     
         21 . The method of  claim 14 , wherein said selectively positioning the lattice structure comprises selectively positioning the lattice structure wherein a longitudinal position of the at least one joint segment corresponds to a region at which the first hollow structure defines a change in a cross-sectional flow area of the first internal passage. 
     
     
         22 . The method of  claim 14 , wherein said selectively positioning the lattice structure comprises selectively positioning the lattice structure wherein a longitudinal position of the at least one joint segment corresponds to a region at which structural support from the lattice structure facilitates stabilization of a position of the first segmented core. 
     
     
         23 . The method of  claim 14 , wherein said selectively positioning the lattice structure comprises selectively positioning the lattice structure wherein the at least one extension segment is formed from at least one extruded tube segment. 
     
     
         24 . The method of  claim 14 , wherein said introducing the component material in the molten state into the cavity comprises introducing the component material such that a performance of the component material in a solid state is not degraded by the at least partial absorption of the first material. 
     
     
         25 . The method of  claim 24 , wherein said introducing the component material in the molten state into the cavity comprises introducing an alloy in a molten state into the cavity, wherein the first material comprises at least one constituent material of the alloy. 
     
     
         26 . The method of  claim 14 , wherein said selectively positioning the lattice structure comprises selectively positioning the lattice structure wherein the at least one joint segment and the at least one extension segment are coupled together by at least one of an externally flush joint, a diverging joint, and a converging joint.