Abstract: The invention is a honeycomb structure suitable for use with cryogenic materials. In detail, the invention comprises a honeycomb sandwich structure 10 having a titanium core 14, a first face sheet 12 made of aluminum alloy suitable for high-temperature applications, and a second face sheet 16 made of titanium bonded together by a high-temperature thermoplastic adhesive. Preferably the core 14 is made of Ti-15V-3Cr-3Sn-3 aluminum, Ti-6Al-4V and/or Ti-3Al-2.5V. The first face sheet 12 is, preferably, made out of Al-8Fe-7Ce, Al-13Fe-4.6V, Al-1OFe-1Mo1V and Al-6Fe-6Ni-2Cr or other aluminum alloys suitable for use at temperatures in excess of 600.degree. F. The second face sheet 16 is, preferably, made of Ti-6Al-4V, Ti-6Al-2Sn-4Zr-2Mo or Ti-15V-3Cr-3Sn-3Al. Preferably, the adhesive 18a, 18b is a thermoplastic material such as polyetheretherketone, polyphenylquinoxaline or a polyamide-imide.

Abstract: A process of precision forging of titanium or a titanium alloy in which the forging stock and a segmented die are first heated to forging temperature while separated, and are then assembled together and heated again to that temperature, with the stock being covered by a protective coating preferably containing glass grit, and the die sections being coated with lubricant. The heated die and contained heated forging stock are then inserted in a heated holder and the stock subjected to forging force, to partially but not completely deform the stock to the shape of the die cavity, following which the die and stock are separated and the stock allowed to cool, flashing is removed from the stock, the die is cleaned, the die and stock are recoated and then reheated separately and then together, and the stock is forged again to assume more closely the shape of the die cavity.