Microstructure and hardness of Cu-12% Fe composite at different drawing strains

Abstract

Cu-12% Fe (in weight) composite was prepared by casting, pretreating, and cold drawing. The microstructure was observed and Vickers hardness was measured for the composite at various drawing strains. Cu and Fe grains could evolve into aligned filaments during the drawing process. X-ray diffraction (XRD) was used to analyze the orientation evolution during the drawing process. The axial direction of the filamentary structure has different preferred orientations from the radial directions. The strain of Fe grains linearly increases with an increase in the drawing strain up to 6.0, and deviates from the linear relation when the drawing strain is higher than 6.0. With an increase in the drawing strain, the microstructure scales of Fe filaments exponentially decrease. The density of the interface between Cu and Fe phases exponentially increases with an increase in the aspect ratio of Fe filaments. There is a similar Hall-Petch relationship between the hardness and Fe filament spacing. The refined microstructure from drawing deformation at drawing strains lower than 3.0 can induce a more significant hardening effect than that at drawing strains higher than 3.0.

Microstructure and properties of cold drawing Cu-2.5% Fe-0.2% Cr and Cu-6% Fe alloys

“…In our previous studies, the strain of Fe dendrite linearly increased with an increase in the drawing strain up to 6, and deviated from the linear relationship when the drawing strain was higher than 6 in Cu-12% Fe (in weight) (Lu et al, 2014). The thickness, width, and spacing of Fe ribbons in the filamentary structure exponentially decreased with an increase in the drawing strain.…”

Modifying the structure and properties of Cu-Fe composites by the methods of pressure formation

“…At the same time, these methods make it possible to obtain layered ingots with round cross sections suitable for further working under pressure (by rolling, extru sion, drawing). The authors of [7,8] have investigated the structure and properties of a Cu-Fe composite obtained by casting with subsequent drawing. After casting, the structure of the composite is characterized by the presence of large dendrites of iron with a certain amount of dispersed particles of iron.…”

“…After casting, the structure of the composite is characterized by the presence of large dendrites of iron with a certain amount of dispersed particles of iron. Upon deforma tion by drawing, iron dendrites become elongated in the direction of drawing up to the formation of nan odimensional fibers [7][8][9]. The cross sections of den drites have a filamentary morphology that results from the joint deformation of copper and iron, which is characteristic of fcc fibers in a bcc matrix [10].…”

“…The cross sections of den drites have a filamentary morphology that results from the joint deformation of copper and iron, which is characteristic of fcc fibers in a bcc matrix [10]. X ray diffraction analysis has shown that the fibrous struc ture formed in the process of drawing is characterized by preferred crystallographic orientations of the Cu 〈110〉 and Fe 〈100〉 types in the longitudinal section and Cu 〈111〉 and Fe 〈110〉 types in the transverse sec tion [7]. The formation of a similar structure in the Cu-Fe composite was also observed in the case of deformation by cold rolling [1].…”

Microstructure and Properties of Multifibre Composites

“…Thickness, width and distribution of Fe fibers in the fibrous structure decrease rapidly with the increase of the strain during drawing. In the study [6] an experiment and simulation were made of thermal instability of Fe fibres which were deformed during drawing (actual deformation 8.2). It was presented that when annealing temperature is below 500°C the Fe fibres still maintain the shape of fibres before the drawing, however, with the temperature increase to 600°C (temperature of iron recrystallization), the longitudinal fibres start to break and to coagulate.…”