Weapon barrel and method of making same

Abstract

An improved barrel for use in a weapon includes a housing which is cast as one piece of a directionally solidified superalloy which is free of generally spherical, randomly oriented crystals. The housing has first properties in a direction extending parallel to its central axis and properties which are different than the first properties in a direction transverse to the central axis of the housing. The superalloy forming the housing may be directionally solidified with a columnar grain crystallographic structure. Alternatively, the superalloy of the housing may be directionally solidified with a plurality of single crystal sections, one or more of which extend between opposite end portions of the housing. As another alternative, the superalloy may be directionally solidified as a single crystal which extends between opposite end portions of the housing.

Having described the invention, the following is claimed: 
     
         1 . A barrel for use in a weapon, said barrel comprising a housing enclosing a passage which extends between opposite end portions of said housing and along which a projectile moves during use of said weapon, said housing being cast as one piece of a superalloy directionally solidified from a first end portion of said housing to a second end portion of said housing in a direction which extends parallel to a longitudinal central axis of said passage, said superalloy of said housing having first properties in a direction extending parallel to the longitudinal central axis of said passage and properties which are different than said first properties in a direction transverse to the longitudinal central axis of said passage. 
     
     
         2 . A barrel as set forth in  claim 1  wherein said superalloy of said housing is cast with a columnar grain crystallographic structure with longitudinal axes of the columnar grains extending parallel to the longitudinal central axis of said passage. 
     
     
         3 . A barrel as set forth in  claim 1  wherein said superalloy of said housing is cast with a plurality of single crystal sections, at least one of said single crystal sections extends between said first and second end portions of said housing. 
     
     
         4 . A barrel as set forth in  claim 1  wherein said superalloy of said housing is cast as a single crystal which extends between said first and second end portions of said housing. 
     
     
         5 . A method of casting a barrel for use in a weapon, said method comprising the steps of casting a first portion of the barrel as a single crystal having a primary orientation axis and secondary orientation axes, and casting a second portion of the barrel as a single crystal having a primary orientation axis which is parallel to the primary orientation axis of the first portion of the barrel and secondary orientation axes which are skewed relative to the secondary orientation axes of the first portion of the barrel. 
     
     
         6 . A method as set forth in  claim 5  wherein said step of casting a first portion of the barrel as a single crystal includes solidifying molten metal which extends from a first end portion of the barrel to a second end portion of the barrel to form the first portion of the barrel as a single crystal with an extent which is at least as great as a distance between the first and second end portions of the barrel, said step of casting a second portion of the barrel as a single crystal includes solidifying molten metal which extends from the first end portion of the barrel to the second end portion of the barrel to form the second portion of the barrel as a single crystal with an extent which is at least as great as the distance between the first and second end portions of the barrel. 
     
     
         7 . A method as set forth in  claim 5  further including the step of providing an annular array of single crystal seeds having parallel primary orientation axes, at least some of the single crystal seeds in the annular array having secondary orientation axes are skewed relative to the primary orientation axes of the single crystal seeds.