Mechanical properties of copper/bronze laminates: Role of interfaces

Abstract

a b s t r a c tInterfaces play a crucial role in mechanical behaviors of both laminated and gradient structured materials. In this work, copper/bronze laminates with varying interface spacing were fabricated by accumulative roll bonding and subsequent annealing to systematically study the interface effect on mechanical properties. Heterogeneities exist in chemical composition, grain size, hardness and texture across the interfaces. Simultaneous improvement of strength and ductility with decreasing interface spacing is found in tensile tests. Extra geometrically necessary dislocations (GNDs) are found to accumulate in the vicinity of interfaces, which is due to mechanical incompatibility across the interfaces. Importantly, an interface-affected zone spanning a few micrometers was found, which is not affected by interface spacing. These observations suggest the existence of an optimum spacing, which may produce the highest hardening capacity and ductility without sacrificing strength.

Strain Rate Effect on Tensile Behavior for a High Specific Strength Steel: From Quasi-Static to Intermediate Strain Rates

“…In our previous paper [21], such a transient deformation stage has been found to be caused by the back stress hardening due to the deformation incompatibility between different phases over a strain regime corresponding to the elasto-plastic transition stage. Similar behavior in the hardening rate has also been found recently in the other heterogeneous materials, such as gradient structure [57,58], heterogeneous lamella structure [59] and multilayer laminates [60]. During the plastic deformation of this HSSS, load transfer and strain partitioning between two phases will occur since the softer fcc austenite phase are easier to deform than the harder B2 phase.…”

Heterogeneous multi-layered IF steel with simultaneous high strength and good ductility

“…In the past several years, achieving simultaneously high strength and good ductility has been realized by utilizing combinations of length scale, such as multi-layered materials, and bimodal (or multimodal) grain size distributions [1][2][3][4][5][6][7][8][9]. The results of these studies have shown that it is possible in some cases to do better than just a simple trade-off between strength and ductility (i.e.…”

“…The results of the last method will be discussed in detail. Different to other reported multi-layered materials, such as copper with bronze [1], Cu-10Zn with Cu [4], and Nb with Cu [5,12,13], single phase IF steel sheets with different initial structures (deformed and annealed) were stacked alternatively into multi-layers in the present experiment. The stacked plates were "welded" together by hot compression, followed by hot/cold deformation.…”

“…Furthermore, interfaces in the multi-layered materials are believed to be responsible for the observed high strain hardening and ductility, across which there were heterogeneities in * To whom any correspondence should be addressed. [1]. Some researchers have found that gradient distribution of stress near the interface significantly contributes to working hardening in multi-layered metals.…”

The Evolution of Strain Gradient and Anisotropy in Gradient-Structured Metal

“…[6,7,12,13] Recently, several promising strategies for achieving simultaneous high strength and high ductility have been proposed by tailoring microstructures through heterogeneous and/or hierarchical structures. [2][3][4][5][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] Among them, the gradient structure, where the grain size or the substructure size changes gradually along the depth, [5,[20][21][22][23][24][25][26] has great potential in engineering applications due to their superior combinations of strength and ductility. The tensile properties and underlying deformation mechanisms of the gradient-structured metals have been reported recently.…”