Towards Manufacturing of Ultrafine-Laminated Structures in Metallic Tubes by Accumulative Extrusion Bonding

A severe plastic deformation process, termed accumulative extrusion bonding (AEB), is conceived to steady-state bond metals in the form of multilayered tubes. It shown that AEB can facilitate their solid-state, like process roll (ARB). The steps involve iterative extrusion, cutting, expanding, restacking, and annealing. As iterated, laminated structure layer thicknesses decrease within tube wall, while wall thickness outer diameter remain constant. Multilayered bimetallic tubes with approximately 2 mm 25.25 copper-aluminum are produced at 52% radial strain per pass contain eight layers. Furthermore, copper-copper 68% two amount metal-to-metal interfaces grain measured using optical microscopy. After detailed examination, only bimetal deformed found bonded. yield strength extruded improves from 83 MPa 481 MPa; a 480% increase. Surface preparation, as described by thin film theory, imposed identified discussed key contributors enact successful interface. Unlike ARB, does not occur ~50% revealing significant role more complex geometry relative sheets solid-state bonding.