In the bright-field TEM image of the Ni–SiCNP composite milled for 24 h, it can be seen that the dispersed SiCNP are located either in the matrix, within twin boundary sites or on GB, as shown in Fig. 7. Stacking faults are also observed in the Ni–SiCNP composites, because the addition of SiCNP to the nickel matrix results in an overall reduction in stacking fault energy (SFE). Moreover, Fig. 7 also provides the evidence of the interaction between the dislocation lines and the SiCNP, where the latter aids to hinder dislocation motion.