Thermal Stability and Properties of Deformation-Processed Cu-Fe In Situ Composites

Abstract

This paper investigated the thermal stability, tensile strength, and conductivity of deformation-processed Cu-14Fe in situ composites produced by thermo-mechanical processing. The thermal stability was analyzed using scanning electronic microscope and transmission electron microscope. The tensile strength and conductivity were evaluated using tensile-testing machine and micro-ohmmeter, respectively. The Fe fibers in the deformation-processed Cu-14Fe in situ composites undergo edge recession, longitudinal splitting, cylinderization, break-up, and spheroidization during the heat treatment. The Cu matrix experiences recovery, recrystallization, and precipitation phase transition. The tensile strength and conductivity first increase with increasing temperature of heat treatment, reach peak values at different temperatures, and then decrease at higher temperatures. The value of parameter Z of the in situ composite reaches the peak of 2.86 x 107 MPa2 pct IACS after isothermal heat treatment at 798 K (525 °C) for 1 hour. The obtained tensile strength and conductivity of the in situ composites are 907 MPa and 54.3 pct IACS; 868 MPa and 55.2 pct IACS; 810 MPa and 55.8 pct IACS; or 745 MPa and 57.4 pct IACS, at η = 7.8 after isochronal heat treatment for 1 hour. This paper investigated the thermal stability, tensile strength, and conductivity of deformationprocessed Cu-14Fe in situ composites produced by thermo-mechanical processing. The thermal stability was analyzed using scanning electronic microscope and transmission electron microscope. The tensile strength and conductivity were evaluated using tensile-testing machine and micro-ohmmeter, respectively. The Fe fibers in the deformation-processed Cu-14Fe in situ composites undergo edge recession, longitudinal splitting, cylinderization, break-up, and spheroidization during the heat treatment. The Cu matrix experiences recovery, recrystallization, and precipitation phase transition. The tensile strength and conductivity first increase with increasing temperature of heat treatment, reach peak values at different temperatures, and then decrease at higher temperatures. The value of parameter Z of the in situ composite reaches the peak of 2.86 9 10 7 MPa 2 pct IACS after isothermal heat treatment at 798 K (525°C) for 1 hour. The obtained tensile strength and conductivity of the in situ composites are 907 MPa and 54.3 pct IACS; 868 MPa and 55.2 pct IACS; 810 MPa and 55.8 pct IACS; or 745 MPa and 57.4 pct IACS, at g = 7.8 after isochronal heat treatment for 1 hour.

Microstructure and Strengthening Model of Cu–Fe In-Situ Composites

“…Cu-Fe in-situ composites have a high conductivity, high strength, and low cost [1][2][3][4][5][6]. However, their strength and conductivity are decreased by the substantial solid solubility of Fe atoms in the Cu matrix at high temperatures, and the slow precipitation speed at low temperatures [7,8].…”

Effect of Alternating Magnetic Field on the Microstructure and Solute Distribution of Cu–14Fe Composites

“…The conductivity of composites could be improved by long time diffusion annealing, but the strength would decrease rapidly because of the coarsening of Fe fibers during heat treatment process. 18,19) Addition of extra alloy elements could improve the strength to some extent, but the conductivity and cold workability would be deteriorated. Ag could comprehensively improve the strength and conductivity of Cu-Fe composites, because the conductivity of Ag is excellent, and Ag has an electronic structure and crystal structure similar to Cu.…”

Influences of Alternating Magnetic Fieldson the Growth Behavior and Distribution of the Primary Fe Phasein Cu-14Fe Alloys during the Solidification Process

“…Cu-M alloys have been the subjects of considerable studies where M indicates body-centered cubic (BCC) crystal transition metals [2] such as Cr [3][4][5], Fe [6][7][8], Nb [9][10][11], and Mo [12,13] as well as face-centered cubic (FCC) crystal metals such as Ag [14,15]. The Cu-Fe alloy has attracted the attention of researchers because of the effective strengthening and industrial application.…”