Mechanical properties of diffusion bonded beryllium ingot sheet

Abstract

A technique for producing thick beryllium plate from ingot source material by diffusion-bonding together thin sheets is described. The bonds produced are at least as strong as the matrix, and are produced under conditions where no significant grain growth occurs. The laminated plate has better mechanical properties than the sheet from which it was made, and properties substantially superior to sheet of similar thickness rolled directly from the ingot. Room temperature tensile elongations of approximately 18 pct were observed in the laminated plate. Directly rolled plate of similar thickness normally exhibits 2 to 4 pct elongation, and the sheet from which the laminate was made failed after about 12 pet elongation. The increased ductility of the laminate is a consequence of the compressive creep deformation accompanying bonding and most likely results from a dislocation substructure, produced by the deformation, which differs from the substructure developed by annealing.