Fig. 1 Microstructures of as-cast composites: a W3P3 hybrid specimen at low magnification (the whiskers of large size showing by arrows); b P6 specimen at low magnification; c W3P3 hybrid specimen at high magnification (the whiskers of large size showing by arrows); d P6 specimen at high magnification

Fig. 2 Micrographs showing reinforcement/matrix interfaces in as-cast microstructures: a whisker/matrix interface bonding for W3P3 hybrid composite; b SiCp/matrix interface bonding for W3P3 hybrid composite; c SiCp/matrix interface bonding for P6 composite

Fig. 3 Schematic drawing of hot compressed composites specimen

Fig. 4 Corrected true stress–strain curves for W3P3 hybrid composite (dotted lines) and P6 composite (solid lines) at different strain rates at different temperatures: a 300 °C, b 350 °C, c 400 °C, d 450 °C

Fig. 5 The corrected flow stress (at ε = 0.5) of the two composites as a function of \( { \lg }\,\dot{\varepsilon } \) at 300 and 450 °C

Fig. 6 Fitting curves to describe the relationship between lgσ and lg\( \dot{\varepsilon } \): a W3P3 hybrid composite; b P6 composite

Fig. 7 Processing map at the strain of 0.5 for W3P3 hybrid composite

Fig. 8 Processing map at the strain of 0.5 for P6 composite

Fig. 9 Micrograph clearly showing whisker breakage and whisker/matrix interfacial debonding (showing by arrows) deformed at 300 °C/0.0001 s-1 for W3P3 hybrid composite

Fig. 10 Micrographs showing a SiC particles structural intact and b SiCp/matrix interfacial bonding deformed at 300 °C/0.0001 s-1 for P6 composite

Fig. 11 Microstructures showing adiabatic shear bands or flow localization: a P6 composite deformed at 350 °C/0.1 s-1; b W3P3 hybrid composite deformed at 450 °C/0.1 s-1

Fig. 12 Micrographs showing reinforcement/matrix interfaces: a SiCp/matrix interface decohesion for P6 composite deformed at 350 °C/0.1 s-1; b whisker/matrix interface debonding for W3P3 hybrid composite deformed at 400 °C/0.1 s-1

Fig. 13 Higer magnification optical microstructure showing wedge crack deformed at 450 °C/0.0001 s-1 for P6 composite

Fig. 14 ln σ versus \( { \ln }\,\dot{\varepsilon } \) plots a and σ versus \( { \ln }\,\dot{\varepsilon } \) plots b at different temperatures for W3P3 hybrid composite

Fig. 15 ln σ versus \( { \ln }\,\dot{\varepsilon } \) plots a and σ versus \( { \ln }\,\dot{\varepsilon } \) plots b at different temperatures for P6 composite

Fig. 16 Variation of flow stress at the strain of 0.5 with strain rate at different test temperatures a and 1000/T versus ln (sinh (ασ)) plots at the strain of 0.5 at different strain rates for calculating activation energy for W3P3 hybrid composite b

Fig. 17 Variation of flow stress at the strain of 0.5 with strain rate at different test temperatures a and 1000/T versus ln (sinh (ασ)) plots at the strain of 0.5 at different strain rates for calculating activation energy for P6 composite b

Fig. 18 Apparent activation energies at the hot working domains for W3P3 hybrid and P6 composites