Lucas-Milhaupt Brazing Alloy Aluminum Flux Cored AL822

The Lucas-Milhaupt 99088 AL822 is a flux cored aluminium brazing alloy for joining aluminium components.

Aluminium brazing is a different proposition from copper brazing, and the difference is the oxide layer.

Aluminium forms an oxide film on its surface immediately and continuously on exposure to air. That film has a melting point far above the aluminium beneath it, so it does not melt away during brazing, and it prevents the filler wetting the base metal.

The filler cannot bond to metal it cannot reach, so the oxide has to be removed and prevented from reforming during heating. That is what the flux does, and it is why aluminium brazing alloys are supplied flux cored or used with a dedicated aluminium flux.

The second difficulty is the narrow temperature window. Aluminium brazing filler melts at a temperature not far below the melting point of the aluminium being joined, so the margin between a properly brazed joint and a collapsed one is small. Aluminium also gives no colour change as it approaches melting, so there is no visual warning.

Technique relies on heating the base metal and watching the filler behaviour rather than the metal's appearance.

Confirm the alloy suits the aluminium alloys being joined, clean the surfaces mechanically immediately before brazing, control the heat carefully, and remove flux residue thoroughly since aluminium fluxes are corrosive.

Brand

Lucas-Milhaupt

SKU

99088

Category

Brazing Alloys

Weight

0.05 lbs

Dimensions

21.00" x 1.00" x 1.00"

Price

$31.00

Availability

In stock

Rating

0 / 5.0