Method for forming non-bonded regions in multi-layered metallic armor

A method of forming a multi-layered metallic part, comprising:

• stacking metallic layers, each made of a metallic material having a ductility, to form a multi-layered metallic assembly;
• interposing a diffusion-bond preventing element directly between adjacent ones of the metallic layers of a plurality of adjacent ones of the metallic layers of the multi-layered metallic assembly;
• compressing the adjacent ones of the metallic layers against the diffusion-bond preventing element to deform each one of the adjacent ones of the metallic layers around the diffusion-bond preventing element;
• and
• diffusion bonding each one of the plurality of adjacent ones of the metallic layers to each other at locations other than a location contiguous with the diffusion-bond preventing element, such that an entirety of a top, an entirety of a bottom, and an entirety of all sides of the diffusion-bond preventing element are completely contiguous with and completely insulated by the adjacent ones of the metallic layers and such that the adjacent ones of the metallic layers, at the location contiguous with the diffusion-bond preventing element, are not diffusion bonded to the diffusion-bond preventing element, to produce the multi-layered metallic part having a non-bonded region between the adjacent ones of the metallic layers at the location contiguous with the diffusion-bond preventing element;
• wherein the diffusion-bond preventing element between any one of the plurality of adjacent ones of the metallic layers is staggered relative to the diffusion-bond preventing element between any other one of the plurality of adjacent ones of the metallic layers such that no diffusion-bond preventing element between one of the plurality of adjacent ones of the metallic layers overlaps, in a direction across thicknesses of the metallic layers, with a diffusion-bond preventing element between a next adjacent one of the plurality of adjacent ones of the metallic layers.