Arconic Technologies LLC

Alcoa Inc.

Michael P Danz

Stephen F Baumann

Raymond J Kilmer

John B Eye

Ning Sun

Baolute Ren

Marvin Goins

An aluminum alloy brazing sheet has a 3XXX, 1XXX or 6XXX core, an interliner and a 4XXX brazing layer without added Mg. The interliner has Bi and Mg, the magnesium migrating to the surface of the brazing sheet during brazing and reducing the aluminum oxide to facilitate brazing without flux in a controlled inert atmosphere with reduced oxygen.

Aluminum material for fluxfree cab brazing

Aluminum material for fluxfree CAB brazing

An apparatus, material and method for forming a brazing sheet has a composite braze liner layer of low melting point aluminum alloy and 4000 series braze liner. The low melting point layer of the composite braze liner facilitates low temperature brazing and decrease of the diffusion of magnesium from the core into the composite braze liner. The reduction of magnesium diffusion also lowers the formation of associated magnesium oxides at the braze joint interface that are resistant to removal by Nocolok flux, thereby facilitating the formation of good brazing joints through the use of low temperature controlled atmosphere brazing (CAB) and Nocolok flux. The apparatus also enables the production of brazing sheet materials with high strength and good corrosion property.

Composite braze liner for low temperature brazing and high strength materials

A wrought aluminum sheet product having a textured surface for improved heat transfer properties. A plurality of textured features having dimensions of about 1-50 microns is roll textured onto one or both sides of the sheet. The aluminum sheet may be used as the fins or tubing of a heat exchanger.

Micro-textured heat transfer surfaces

Growing community of inventors

Lancaster, PA, United States of America

Michael P Danz