Abstract: A metallurgical bond at the interface between an aluminum-lithium core alloy and a metallic liner is achieved by first forming a mechanical bond along the interface between the core and liner under moderated temperature and reduction conditions, and then heating the composite without simultaneous reduction to cause diffusion of the elements across the core-liner interface. The result is a metallurgical bond securing the layers together to form a composite which can be worked, shaped, and fabricated by normal reduction techniques into a full range of products without the discoloration and fouling problems otherwise typical of aluminum-lithium alloys.