Fig. 1 Schematic representation of fabrication process of CMCs corresponding to Cu-Cr-rGO system

Fig. 2 SEM micrographs of Cu a, Cr b powders used as the raw materials

Fig. 3 XRD patterns of the dried powder mixtures a, the sintered composites b

Fig. 4 XRD patterns of GO a, rGO collected from the sintered 0Cr composite b, rGO/Cr mixtures collected from the sintered 0.5Cr c, 2Cr d, 4Cr e composites

Fig. 5 SEM micrographs of the dried powder mixtures showing rGO distribution: a 0Cr, b 0.5Cr, c 2Cr, d 4Cr

Fig. 6 SEM-BSE micrographs of the sintered bulk composites by SPS: a 0Cr, b 0.5Cr, c 2Cr, d 4Cr. The insets show the high-magnification micrographs of the rGO

Fig. 7 High-magnification SEM-BSE image a and EDX results b-d of the sintered composite: a SEM-BSE image, b A point, c B point, d C point

Fig. 8 SEM micrographs of rGO and Cr in the sintered composites: a low-magnification image; b rGO; c, d Cr particle, where d is the higher-magnification image from the rectangle frame in c

Fig. 9 Room-temperature compressive stress-strain curves of the sintered bulk composites

Fig. 10 SEM-BSE micrographs of the room-temperature deformed 4Cr composite: a low-magnification image, b banded rGO agglomeration, c deformed rGO around Cr particles. The dark arrows indicate the compressive axis

Fig. 11 TEM micrographs obtained from the deformed sample showing a high density of dislocations in Cu matrix. The inset shows the blocking of rGO to dislocations

Fig. 12 SEM images of compressive fractography of the sintered bulk composites showing a broken rGO, b pulled-out rGO, c warped rGO, d fractured Cr particles (white gridlines). The white arrows in a-c mark the rGO. The black arrows in d mark the tiny cracks