Microstructure and Mechanical Properties of Explosively Welded Nickel/Steel Composite Plate Interface

Abstract:

High-performance pure nickel N6/steel 45# composite plate (N6/45#) was prepared using explosive welding technique. The microstructure of the interface and nearby regions was characterized and analyzed by optical microscope, scanning electron microscope, electron backscatter diffraction, and mechanical property testing, and the microstructural features and mechanical properties of the explosive welding interface were explored. The results show that along the direction of explosive welding, the pure nickel N6/steel 45# composite plate interface gradually evolves from a flat bond to a typical wavy bond. The grains at the crests and troughs exhibit high heterogeneity, and the closer to the interface, the finer the grains. Recrystallization and low-stress deformation bands are formed at the bonding interface. Nanoindentation tests reveal that plastic deformation occurs in the interfacial bonding zone, and the nanohardness values in the crest regions are higher than that in the trough regions. The tensile strength of the N6/45# interface is 599.8 MPa, with an average shear strength of 326.3 MPa. No separation phenomenon is observed between N6 and 45# after the bending test.