Fe–Cu Nanocomposites by High Pressure Consolidation of Powders prepared by Electric Explosion of Wires

Abstract

In the present paper, preparation of nanocomposite powders of mutually immiscible Fe and Cu metals with different Fe-to-Cu ratios by electric explosion of wires and their processing into bulk materials are reported. Near-fully dense nanocrystalline Fe-Cu specimens with high compressive and bending strengths are obtained by high pressure consolidation/cold sintering of the electrically exploded powders at 3 GPa. Reduction treatment in an H 2 -flow prior to consolidation results in an intimate contact between the oxide free powder surfaces and in an excellent inter-particle bonding integrity. The Cu-rich composition exhibits an attractive combination of high strength and relatively low electrical resistivity.

Effect of Cold-Sintering Parameters on Structure, Density, and Topology of Fe–Cu Nanocomposites

“…Apparently, there is not enough copper in the latter sample to fully fill the empty spaces between the relatively rigid grains of iron. The calculated densities in Figure 2 are in good agreement with our earlier experimental results of cold sintering of Fe-Cu nanopowders at pressures up to 3 GPa [42]. At 2.5 GPa, the calculated and experimental densities are practically identical.…”

“…Another observation from Figure 2 is that lower relative densities are achieved for Fe-Cu samples with higher Fe (lower Cu) content, again in agreement with the experimental results [42]. The dependence of the simulated relative and absolute density of samples cold sintered at 3 and 5 GPa on iron content is presented in Figure 3.…”

“…Earlier on, we experimentally investigated the formation of Fe-Cu nanocomposites by cold sintering of bimetallic nanopowders [42]. Before high pressure consolidation, the samples were treated in a hydrogen flow at 450 • C to remove the surface oxide layer from the nanoparticles.…”

“…Such surface oxide films are formed even when the ultra-clean iron and copper surfaces are exposed to air at room temperature [48] and can compromise the compressibility of nanopowders. The other factor is the significantly larger (5-10 fold) average diameter of the nanopowders used in the experiment [42] compared to those used in the simulations and the correspondingly different density that can be achieved by these particles at a given pressure.…”

Special Section on Exothermic and Non‐Isothermal Isothermal Processing of Advanced Materials

“…Interaction of NiAl Intermetallic during SHS synthesis with Ta Substrate [9] Fe-Cu Nanocomposites by High Pressure Consolidation of Powders prepared by Electric Explosion of Wires [10] SHS synthesis, SPS densification, and mechanical properties of nanometric tungsten [11] We hope that this special issue will be of interest to the international scientific community and useful to young researchers working in the field of innovative processing and advanced high-performance materials.…”