Control of layer continuity in metallic multilayers produced by deformation synthesis method

In this investigation, Fe/Ag and Ni/Ag multilayers were fabricated by a bonding and rolling method. The hard phase of the multilayer, such as Ni and Fe, necks, elongates and finally ruptures with increasing thickness reduction. The morphological features of the layer with thickness reduction were different with initial thickness ratio. The changes of the microstructures for Fe/Ag and Ni/Ag multilayers were examined on the basis of the plastic instability criteria for diffused necking. The critical reduction for necking of the hard constituent phase of the layer is dependent on the flow properties of the phases such as strength coefficient and strain hardening exponent, and the initial thickness ratio of the constituent phases.