Microstructure and mechanical properties of the Ag/316L composite plate fabricated by explosive welding

Abstract

In the present research, the Ag/316L composite plate was fabricated by the explosive welding. Its microstructure and mechanical properties were studied and the results reveal that the explosively welded Ag/316L composite plate has typical interfacial wavy structure which has the average period of 900 μm and average height of 400 μm. Along the Ag/316L composite interface, the transition layer, melted region and Ag rich layer are formed discontinuously. The γ-Fe particles are enveloped in the melted region with relatively homogeneous distribution. Moreover, some Fe2O3 oxides are formed in the melted region. The violent collision by explosive welding has resulted in great deformation in the region adjacent to the interface, which promotes the thorough recrystallization in Ag side and abundant substructures in 316L stainless steel side. Such a microstructure evolution increases the microhardness of the area adjacent to the interface. The Ag/316L composite plate exhibits good bending properties without any interfacial crack, but the discontinuously distributed oxides are formed along the interface, which would be detrimental to the deformability by acting as the crack nucleation. The Ag/316L composite plate possesses the average yield strength, ultimate tensile strength and elongation of 350 MPa, 690 MPa and 39 %, respectively. And its average shear strength is 177 MPa. Such mechanical properties should be attributed its good interfacial structure and refined grains.