Grumman Aerospace Corporation

Edmund Y Ting

James R Kennedy

Alexander Lazarev

Richard T Schumacher

In a Bridgman-type apparatus for growing single crystals, a pair of different gradient sections is located around the respective liquid and solid phases of a sample undergoing solidification. Each gradient section is chosen with thermal characteristics matching the thermal properties of the sample and more particularly taking into consideration the difference in thermal conductivity between the liquid and solid phases. The result is a better match or control of the temperature profile between the furnace and the sample material undergoing solidification which results in improved interface shape control.

Crystal-growth furnace for interface curvature control

Diffusion bonding of aluminum alloy objects of different sizes and shapes may be greatly improved when the surface of the object is exposed to a mechanical deformation cycle which forms a cold-worked surface microstructure, followed by a heat treatment cycle to produce recrystallization of the surface layer. The method of the invention results in the formation of finer grains at the surface which enhances the strength of a diffusion bond.

Method for diffusion bonding of metals and alloys using mechanical

Diffusion bonding of aluminum alloy objects of different sizes and shapes may be greatly improved when the surface of the object is exposed to a thermal spray source which deposits fine metal particles on the surface. Rapid quenching of solidification occurs at the surface. Such treatment results in the formation of finer grains at the surface which enhances the strength of a diffusion bond.

Method for diffusion bonding of metals and alloys using thermal spray

Diffusion bonding of aluminum alloy objects of different sizes and shapes are greatly improved when the surface of the object is exposed to a high energy source which causes a heat treatment or melting and rapid quenching or solidification at the surface. Such treatment results in the formation of finer grains at the surface which enhances the strength of a diffusion bond.

Method for diffusion of metals and alloys using high energy source

Diffusion bonding of surface layers of an alloy, such as an aluminum alloy, having surface oxides of low solubility in the alloy includes treating the surface layers to be bonded to remove existing surface oxide coatings, and diffusion bonding the surface layers to one another by placing the alloy to be bonded under sufficient pressure to cause disruption of the oxide coatings by localized surface deformation of the alloy, enhanced by a superplastic microstructure, without substantial deformation of the alloy, i.e., macroscopic deformation approaching zero percent, while heating the alloy in a non-oxidizing atmosphere for a time sufficient for diffusion bonding to occur. The alloy may be treated so that at least the surface layers thereof have a fine grain structure of the type associated with superplastic forming properties. Components may be formed by diffusion bonding and superplastic forming.

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Flushing, NY, United States of America

Edmund Y Ting