Patent ID: 6129261
Filing Date: 2000-10-10
Classification: B21D,B23K

Abstract:
A method of making superplastically formed, diffusion bonded structure using at least two sheets of superplastic and diffusion bondable metal alloys, comprising the steps of:(a) cleaning the metal sheets to activate their surfaces in areas for diffusion bonding;(b) aligning the sheets to provide intimate contact between the sheets at selected locations where diffusion bonding is desired;(c) welding the sheets to form a pack to make a gas-tight seal while providing forming gas inlets into a cavity between the sheets;(d) positioning a template having a desired compression diffusion bonding pattern corresponding to the locations of intimate contact between the sheets on the exterior of the pack in a press between opposed dies;(e) optionally, providing holes within the template between compression pad-ups for the alloys to form into, thereby establishing a part definition;(f) purging the cavity of contaminants by evacuating the cavity or by introducing an inert gas to the cavity;(g) heating the pack to a diffusion bonding temperature for the alloy;(h) pressing the sheets together through the template on the exterior of the pack to bring the sheets into intimate contact at the locations to form diffusion bonds while applying gas pressure to the cavity to inflate the pack to prevent diffusion bonding in areas of the pack that register with the holes in the template.