Multiscale modeling of the anisotropic electrical conductivity of architectured and nanostructured Cu-Nb composite wires and experimental comparison

Abstract

International audienceNanostructured and architectured copper niobium composite wires are excellent candidates for the generation of intense pulsed magnetic fields (> 90T) as they combine both high electrical conductivity and high strength. Multi-scaled Cu-Nb wires can be fabricated by accumulative drawing and bundling (a severe plastic deformation technique), leading to a multiscale, architectured and nanostructured microstructure providing a unique set of properties. This work presents a comprehensive multiscale study to predict the anisotropic effective electrical conductivity based on material nanostructure and architecture. Two homogenization methods are applied: a mean-field theory and a full-field approach. The size effect associated with the microstructure refinement is taken into account in the definition of the conductivity of each component in the composites. The multiscale character of the material is then accounted for through an iterative process. Both methods show excellent agreement with each other. The results are further compared, for the first time, with experimental data obtained by the four-point probe technique, and also show excellent agreement. Finally, the qualitative and quantitative understanding provided by these models demonstrates that the microstructure of Cu-Nb wires has a significant effect on the electrical conductivity

Multiscale modeling of the elasto-plastic behavior of architectured and nanostructured Cu-Nb composite wires and comparison with neutron diffraction experiments

“…(1) Even though grain size effect has been taken into account in this work for Cu-Nb Filamentary wires N = 85 2 , its impact on effective material behavior is not significant, as the volume fraction of fine Cu components is rather small ( 15%). In contrast, other types of Cu-Nb wires, such as the Filamentary wires N = 85 3 (see Gu et al (2017b) for the material descriptions), exhibit a higher volume fraction of ultra-fine Cu grains. The importance of size effects will be studied by multiscale modeling for these Cu-Nb wires.…”

“…Previous studies on the Cu-Nb nanocomposite wires and laminates have focused on textures and their evolution (Lim and Rollett, 2009;Dubois, 2010;Lee et al, 2012;Hansen et al, 2013;Medy, 2016), elasticity (Gu et al, 2017a), dislocation glide (Thilly et al, 2001;Misra and Hoagland, 2007), grain size dependent yield stress/yield criterion (Misra and Hoagland, 2007;Thilly et al, 2009;Nizolek et al, 2015), Bauschinger effect (Thilly et al, 2007;Badinier et al, 2014), hardness (Thilly et al, 2002), ultimate tensile strength (Vidal et al, 2007), Cu-Nb interfaces (Mayeur et al, 2013(Mayeur et al, , 2015Beyerlein et al, 2014), and thermal stability and internal stresses (Vidal, 2006;Dubois et al, 2010;Beyerlein et al, 2014). The electrical behavior of Cu-Nb composites was studied by Gu et al (2015Gu et al ( , 2017b.…”

Texture Evolution and Nanohardness in Cu-Nb Composite Wires

“…The ADB process results in a multi-scale Cu matrix containing continuous parallel Nb fibers with a maximum number of up to 85 4 (N = 85 4 , determined by the number of drawing steps) and with diameters varying in the range of 10 nm to 500 µm. Four different types of specimens were prepared after each pass of the first four ADB process, with N = 85, 85 2 , 85 3 , and 85 4 . These samples were designated by the number of Nb fibers.…”

“…Over the past two decades, Cu-Nb microcomposites have been widely used in defense, aerospace, and magnetic applications for their excellent combination of mechanical properties, high conductivity, and thermal stability [1][2][3][4]. Several techniques have been used to fabricate these materials, including accumulative drawing and bonding (ADB) [5,6], melt and deform [7,8], accumulative roll bonding (ARB) [9][10][11], and magnetron sputtering [12,13].…”

Microstructural Evolution and Mechanical Behavior of Cu/Nb Multilayer Composites Processed by Accumulative Roll Bonding

“…[20][21][22] For example, it was reported that the tensile strength of an Al/Sn multilayer composite was about 2.2 times higher than for pure Al. [23] In a recent study, Cu/Nb nanostructured composites not only exhibited high conductivity [24] and high strength [15] but also held great promise for applications requiring resistance to high-energy radiation damage, [25,26] plastic deformation, [20] and exposure at elevated temperatures. This combination of properties makes multilayer composites attractive for a range of applications.…”