Effect of B4C nanoparticles addition on the refinement of Fe-rich phase in ZL108 alloy

• The addition of B 4 C nanoparticles significantly refines the size of the Fe-rich phase in ZL108 alloy and partially transforms primary Fe-rich phase morphology. • The lattice parameter of Fe-rich phase has been altered and the growth of Fe-rich phase has been suppressed due to the addition of B 4 C nanoparticles. • The elongation of the ZL108 alloy has been significantly improved by reducing the stress concentration caused by Fe-rich phase. Refining effect of B 4 C nanoparticles in ZL108 alloy on Fe-rich phase was studied in this work. It was observed that B 4 C nanoparticles apparently refines the size of the Fe-rich phases and partially transforms Fe-rich phases morphology from hollow polyhedron to petal-like shape. The DSC results show that B 4 C nanoparticles does not affect the initial nucleation temperature of the Fe-rich phase. However, the addition of B 4 C nanoparticles to ZL108 alloy inhibits the growth of Fe-rich phase. The TEM results confirm that the addition of B 4 C nanoparticles alters the lattice parameter of Fe-rich phase due to incorporation of C atoms, thereby suppressing the growth of the Fe-rich phase and ultimately leading to its refinement. From the perspective of fracture behavior, the addition of B 4 C nanoparticles remarkably reduces the stress concentration of Fe-rich phase, and the elongation of the alloy increases by 25.3%. These findings provide a new perspective for further research and development to refine Fe-rich phase.