Effect of boron carbide addition on strengthening mechanisms, cold workability and instantaneous strain hardening behaviour of Cu4Si14Zn nanocomposites

The present work investigates the mechanical alloying (MA) of Cu4Si14Zn (silicon brass) matrix reinforced with B4C particulate nanocomposites (0, 3, 6, 9 and 12 wt%) and consolidated by VHP technique. This research correlates the microstructural modifications and various strengthening mechanisms occurred in sintered specimens on the cold workability and strain hardening behaviour. The sintered nanocomposites were characterized by advanced microscopic techniques such as XRD, SEM, and TEM to identify phase formation, grain refinement, and dislocations respectively. Based on the existing literature, strengthening mechanisms were computed. The deformation behaviour has evaluated and correlated with the strengthening mechanisms. The results explained that the dispersion strengthening (Orowan) has contributed more to the total strength and influenced the plastic deformation behaviour compared to other strengthening mechanisms. The plastic deformation behaviour in terms of true effective stress, true hydrostatic stress, instantaneous Poisson's ratio, and strain hardening index (ni) has investigated. Among the developed nanocomposites, Cu4Si14Zn – 6 wt% B4C reinforced nanocomposite has exhibited superior deformation and strain hardening behaviour with appreciable strength (824 MPa) and strain (44%).