Copper-Iron Filamentary Microcomposites

Abstract

The Cu–Fe system is of particular interest because of the relatively low cost of Fe compared to other insoluble BCC phases such as Nb, Mo, Cr, and Ta. The relatively high solubility of Fe in Cu at high temperatures, coupled with the slow kinetics of Fe precipitation at low temperatures is, however, known to reduce electrical conductivity. The key to improving strength/conductivity properties is to reduce the initial dendrite size and to precipitate Fe effectively in the Cu matrix. Thermomechanical treatments have been employed by some investigators to optimize the strength and conductivity of Cu–Fe microcomposites. The study also shows that refinement of dendrites and easier nucleation of precipitates by the addition of third alloying elements can lead to improved strength/conductivity properties of Cu–Fe microcomposites.

The effects of alloying and pressing routes in equal channel angular pressing of Cu-Fe-Cr and Cu-Fe-Cr-Ag composites

“…Iwahashi et al [19] studied the effect of processing parameters on the grain refinement in Al and found that the subgrain and grain size are in the range of 0.5 µm to 1.5 µm. The microstructural scale of deformation-processed Cu base composites treated by rolling and drawing was found to be much smaller at high deformation strains [1][2][3][4][5][6][7][8][9][10][11]. For example, in Cu-Nb nanocomposites processed by drawing, the spacing between the Nb filaments or the subgrain size in the Cu matrix was approximately 100 nm, while the thickness of the Nb filaments was as thin as 13 nm at the estimated drawing strain of 8.5 [8,11].…”

“…The microstructural development and strengthening mechanism of deformation-processed Cu base microcomposites have been the subjects of extensive studies [1][2][3][4][5][6][7][8][9][10][11]. Deformation processing methods such as drawing or rolling have been employed in such research to refine the microstructure, leading to a fine two-phase microstructure with strong crystallographic textures [1][2][3][4][5][6][7][8][9][10][11].…”

“…Deformation processing methods such as drawing or rolling have been employed in such research to refine the microstructure, leading to a fine two-phase microstructure with strong crystallographic textures [1][2][3][4][5][6][7][8][9][10][11]. The strength of severely deformed Cu base composites exceeds that predicted by the rule of mixtures (ROM), and much discussion has been devoted to the fundamental understanding of the strengthening mechanisms [1][2][3][4][5][6][7].…”

“…The conductivity of the copper is not greatly reduced by the addition of alloying elements with limited solubility [1][2][3][4][5][6][7][8][9][10][11]. The equal-channel angular pressing (ECAP) technique has also been proven to be very useful in improving the strength of ingot-processed metallic alloys through grain refinement to, typically, the submicrometer level [12][13][14][15][16][17][18].…”

“…The advantage of ECAP processing compared to drawing is that the size of the heavily processed composite is not reduced by ECAP, whereas it decreases rapidly with drawing. Hong and his coworkers [9,10,22] have found that the addition of silver increased the strength of Cubased composites greatly. The objective of this study is to study the combined effects of silver addition and ECAP processing on the microstructural evolution and the hardness of Cu-Fe-Cr in situ composites.…”