Method for making layered foil structure

Abstract

A method is set forth for forming a unitary structure having a plurality of deformable foils having first and second sides stacked one upon another with the first sides facing in one direction and the second sides in an opposite direction, each of the foils having an undulating cross-section, adjacent of the foils having their undulations orthogonal to one another and every other one of the foils having parallel orientations. The method comprises positioning a first plurality of parallel rods against the first side of a respective one of the foils and positioning a second plurality of parallel rods against the second side of the same foil with the rods of the second plurality of rods between and parallel to the rods of the first plurality of rods. Thereafter the aforementioned steps are repeated with each next adjacent foil having the rods defining the undulating cross-section thereof at a non-zero angle to the rods of the next adjacent foil. The foils are then diffusion bonded to each other at their points of contact to form a unitary structure and the rods are removed from the unitary structure. An apparatus including combs which bear such rods and a jig having a plurality of generally parallel pins positioned to form a generally rectangular cavity therebetween sized to receive the foils therein in stacked arrangement generally orthogonal to the pins with the pins being spaced to receive the rods of the combs therebetween and extending between the foils also forms a part of the invention.