Processing and Deformation Behavior of Bulk Cu–Nb Nanolaminates

Abstract

Metallic nanolaminates, composed of alternating layers of two dissimilar metals, have attracted significant attention due to both their high strengths and their potential for excellent microstructural stability. While nanolaminates have traditionally been available only in thin-film form, advances in the severe plastic deformation process of accumulative roll bonding (ARB) have enabled the production of 4-mm-thick sheets of copper-niobium nanolaminates containing over 200,000 individual layers (a nominal layer thickness of\20 nm). The ability to produce bulk nanolaminates has greatly expanded the potential applications for these materials and has motivated investigations into formability, deformation behavior, and joining techniques. This paper presents an overview of both the ARB processing technique and recent investigations into the deformation behavior of these novel materials.

Interface-dominant multilayers fabricated by severe plastic deformation: Stability under extreme conditions

“…As a promising alternative, researchers have applied SPD to make layered composites in bulk via a technique called accumulative roll bonding (ARB) [20][21][22]. The ARB process uses an iterative sequence of cleaning, stacking, roll bonding, and cutting to create and refine a lamellar microstructure [23]. This technique has been applied to several different bimetal systems [21,22,[24][25][26][27].…”

“…The material can be further processed down to individual layer thicknesses < 10 nm. [23] The ARB process imposes rolling deformation. Rolling can stabilize certain crystallographic orientations, known as ideal rolling components.…”

Coupled crystal orientation-size effects on the strength of nano crystals

“…These include deposited {001}, {110}, and {111} textures. Severe plastic deformation (SPD) of two-phase composites is another way of forming nanomaterials 37 . These tend to produce textures where the interface planes correspond to {112} planes and the two in-plane directions of the NC Cu phase, the <111> and <110> directions, are highly aligned 38 .…”

Processing of Dilute Mg–Zn–Mn–Ca Alloy/Nb Multilayers by Accumulative Roll Bonding

“…Bimetallic‐multilayered composite sheets that consist of two distinct, alternatively stacked metals have the potential to satisfy these requirements, especially if they comprise low‐density metals, such as Mg. Prior works, not involving Mg, have shown that bimetallic‐layered sheets with very fine individual layer thicknesses, ranging from as low as submicron to nanometer dimensions, can exhibit a plethora of outstanding properties simultaneously . This is due to a change in deformation mechanisms as the region between bimetal interfaces become more constricted and plasticity becomes more limited and difficult to activate .…”

“…This is due to a change in deformation mechanisms as the region between bimetal interfaces become more constricted and plasticity becomes more limited and difficult to activate . Cu/Nb nanolaminates, for instance, have demonstrated the outstanding thermal stability, strength, shock resistance, radiation resistance, and even ductility . Attaining such fine layers involves application of large plastic deformation during the metal‐forming process.…”