Abstract: A method of making a multi-layered composite material having a layer of a first metal and a layer of a second incompatible metal, separate from the first metal, the method involving hot rolling a multi-layered assembly of the first metal; the second metal; and a composite interlayer between the first metal and the second metal; wherein the composite interlayer having a first outer layer of a first composite metal compatible with the first metal; a second outer layer of a second composite metal compatible with the second metal; and an interlayer metal bonded between the first composite metal and the second composite metal; and wherein the first metal is adjacent the first composite metal and the second metal is adjacent the second composite metal; to effect production of the multi-layered composite material. The invention is valuable for producing a bonded composite of a hardened steel, such as an armour steel, with GA14V titanium.