STP460: Diffusion Bonded Scarf Joints in a Metal Matrix Composite

    Olster, E. F.
    Graduate student, Massachusetts institute of Technology, Cambridge, Mass.

    Jones, R. C.
    Associate professormember ASTM, Massachusetts institute of Technology, Cambridge, Mass.

    Pages: 12    Published: Jan 1969


    Abstract

    Joints, approaching 100 percent efficiency, have been obtained in a 2024 aluminum alloy reinforced with type 355 stainless steel wires using a deformation diffusion bonding technique. A scarf joint, whose geometry is dependent upon the critical fiber length and the distance between layers of fibers, was developed for this study. The effect of an aluminum oxide coating on the joining surfaces was investigated, and it was concluded that within the range of bonding parameters used in this study sound joints could be obtained only if the oxide coating was removed immediately before joining. A wide range of joining parameters provided sound joints; however, the ultimate tensile strength of the joined specimen decreased as bonding times increased. The high-strength scarf joint specimens failed with massive debonding along the diffusion bond planes resulting from the composite fabrication technique. These fracture surfaces examined with a scanning electron microscope and appeared nearly identical to fracture surfaces in unjoined, untreated material. The lower-strength scarf joint specimens fractured with little or no debonding along these original bond planes, and when subjected to flexure tests could undergo massive deformation with no indication of macroscopic failure.

    Keywords:

    joining, diffusion bonding, fiber composites, metal matrix, evaluation, tests


    Paper ID: STP49830S

    Committee/Subcommittee: D30.04

    DOI: 10.1520/STP49830S


    CrossRef ASTM International is a member of CrossRef.