Core for an investment casting process

Abstract

A core ( 300 ) for an investment casting process in which a component to be cast has an internal passageway, the internal passageway being provided by the core ( 300 ), the core ( 300 ) comprising: a chimney portion ( 301 ); and a core passage ( 302 ), the chimney portion ( 301 ) extending away from the core passage ( 302 ); wherein the chimney portion ( 301 ) comprises at least one indent, groove or recess ( 306 ).

1 . A core for an investment casting process in which a component to be cast has an internal passageway, the internal passageway being provided by the core, the core comprising: a chimney portion; and a core passage, the chimney portion extending away from the core passage ; wherein the chimney portion comprises at least one indent, groove or recess; wherein the indent, groove or recess extends in a transverse direction across the chimney portion. 
     
     
         2 . A core according to  claim 1 , wherein the core passage has a height, width and breadth wherein the width and breadth are greater than the height, wherein the chimney portion extends in the direction of the height. 
     
     
         3 . A core according to  claim 2 , wherein the core passage is planar. 
     
     
         4 . A core according to  claim 2 , wherein the core is arched. 
     
     
         5 . A core according to  claim 1 , wherein: the chimney portion is perpendicular to the core passage; or the chimney portion extends away from the core passage in a non-perpendicular direction and/or the chimney portion extends away from the core passage at an angle of at least 1° or at least 3° from the perpendicular. 
     
     
         6 . A core according to  claim 1 , wherein the core passage extends from a first end to a second end and the chimney portion connects with the core passage at an intermediate location between the first end and the second end 
     
     
         7 . A core according to  claim 6 , wherein a base of the core passage extends from the first end to the second end. 
     
     
         8 . A core according to  claim 1 , wherein the chimney portion and the core passage each form an internal passageway in the cast component and the formed internal passageways communicate with each other to provide a continuous internal passageway. 
     
     
         9 . A core according to  claim 1 , wherein the indent, groove or recess is disposed relatively close to the core passage. 
     
     
         10 . A ceramic shell for an investment casting process in which a component to be cast has at least one internal passageway, the internal passageway(s) being provided by a core, the ceramic shell comprising: a core comprising: a chimney portion; and a core passage, the chimney portion extending away from the core passage; wherein the chimney portion comprises at least one indent, groove or recess; wherein the indent, groove or recess extends in a transverse direction across the chimney portion, the core having an outer layer of a sacrificial material within the ceramic shell, wherein the chimney portion extends between the core passage and the ceramic shell through the sacrificial material. 
     
     
         11 . A ceramic shell according to  claim 10 , wherein the core passage has a height, width and breadth wherein the width and breadth are greater than the height, wherein the chimney portion extends in the direction of the height. 
     
     
         12 . A ceramic shell according to  claim 11 , wherein the core passage is planar. 
     
     
         13 . A ceramic shell according to  claim 11 , wherein the core is arched. 
     
     
         14 . A ceramic shell according to  claim 10 , wherein: the chimney portion is perpendicular to the core passage; or the chimney portion extends away from the core passage in a non-perpendicular direction and/or the chimney portion extends away from the core passage at an angle of at least 1° or at least 3° from the perpendicular. 
     
     
         15 . A ceramic shell according to  claim 10 , wherein the core passage extends from a first end to a second end and the chimney portion connects with the core passage at an intermediate location between the first end and the second end. 
     
     
         16 . A ceramic shell according to  claim 10 , wherein the sacrificial material is wax-based. 
     
     
         17 . A cast component comprising: at least one internal passageway formed by a core having a chimney portion; and a core passage, the chimney portion extending away from the core passage ; wherein the chimney portion comprises at least one indent, groove or recess; wherein the indent, groove or recess extends in a transverse direction across the chimney portion, wherein the internal passageway has a local area contraction corresponding to the indent, groove or recess. 
     
     
         18 . A cast component according to  claim 17 , wherein the cast component comprises one or more cap sealing apertures at one or more points. 
     
     
         19 . A cast component according to  claim 17 , wherein the cast component is a seal segment for bounding a portion of a main gas path of a gas turbine engine or the cast component is a combustion tile. 
     
     
         20 . A cast component according to  claim 17 , wherein the cast component is a combustion tile.