Non-Corrosive Pastes With Filler-Metals Al-Flux 7028 Range

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D-30827 Garbsen Germany<br />

Phone: ++49 5131 4622 9-0<br />

Fax: ++49 5131 465048<br />

e-mail: Info@flux-loetstoffe.de<br />

www.flux-loetstoffe.de<br />

<strong>Non</strong>-<strong>Corrosive</strong> <strong>Pastes</strong> <strong>With</strong> <strong>Filler</strong>-<strong>Metals</strong><br />

<strong>Al</strong>-<strong>Flux</strong> <strong>7028</strong> <strong>Range</strong><br />

Description: The <strong>Al</strong>-<strong>Flux</strong> <strong>7028</strong> flux paste range contains non-corrosive controlled atmosphere brazing (CAB) flux, <strong>Al</strong>-<strong>Flux</strong><br />

2805, aluminium filler metal, <strong>Al</strong>Si12, with an inorganic carrier system. A variant, Paint-Coating-<strong>Flux</strong>, contains a water based<br />

binder system (see separate information sheet)<br />

Physical Properties Specification (CAB <strong>Flux</strong>)<br />

Appearance: Grey paste K 29-34 %<br />

Boiling <strong>Range</strong> 184 -189°C <strong>Al</strong> 14-17 %<br />

Melting <strong>Range</strong> (<strong>Flux</strong>): 550 -560°C F 47-52 %<br />

Melting <strong>Range</strong> (<strong>Al</strong>Si12): 577 -583°C Fe2O3 max 0.025 %<br />

Odor: Neutral SO4 max 0.010 %<br />

Si O2 max 0.200 %<br />

Cl max 0.020 %<br />

H2O approx 3.000 %<br />

Classification Packaging<br />

<strong>Non</strong>-<strong>Corrosive</strong>-<strong>Flux</strong>-<strong>Pastes</strong> are classified as an irritant<br />

according to current regulations.<br />

Observe usual chemical handling precautions<br />

Please see Material Safety Data Sheet (MSDS) for<br />

additional information.<br />

As per your request<br />

The pastes listed below are available in various viscosities and flux to filler metal ratios to suit specific customer requirements.<br />

Product Name Comment<br />

<strong>Al</strong>-FLUX <strong>7028</strong>E Standard, for general use<br />

<strong>Al</strong>-FLUX <strong>7028</strong> HC II Cesium enhanced, well suited for<br />

applications were high magnesium<br />

materials are used.<br />

<strong>Al</strong>-FLUX <strong>7028</strong> E 45 DI High metal content, suited to robotic<br />

dispensing applications.

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<strong>Non</strong>-<strong>Corrosive</strong> <strong>Pastes</strong> <strong>With</strong> <strong>Filler</strong>-<strong>Metals</strong><br />

<strong>Al</strong>-<strong>Flux</strong> <strong>7028</strong> <strong>Range</strong><br />

<strong>Al</strong>-FLUX <strong>7028</strong> flux pastes contain <strong>Al</strong>-<strong>Flux</strong> 2805 as the active component. <strong>Al</strong>Si12<br />

metal is added as a filler metal.<br />

These pastes are widely used where additional filler metal is required and can<br />

replace most braze operations where filler metal rings and flux pastes are used.<br />

The advantage is that a single product is used. No mixing is required. No filler<br />

metal pre-forms need be manufactured and stocked. <strong>Flux</strong> and filler metal are<br />

applied in a single, controllable operation and the flux to filler metal ratio is<br />

controlled. This reduces unwanted post-braze crystals as a result of over fluxing.<br />

Uses include problematic braze joint areas on furnace brazed aluminium heat<br />

exchangers, for example, large gaps at tube to header joints caused by poor part<br />

stamping. Leaks can be repaired by applying <strong>Al</strong>-<strong>Flux</strong> <strong>7028</strong>E to the leak area and<br />

re-brazing the defective unit.<br />

Multi flow condenser connector block to header pipe brazing is improved by the use of <strong>Al</strong>-<br />

<strong>Flux</strong> <strong>7028</strong>E. <strong>Al</strong>-<strong>Flux</strong> <strong>7028</strong> HC II can be used if the connector material contains significant<br />

amounts of magnesium.<br />

<strong>Non</strong>-clad parts can be joined using these pastes.<br />

<strong>Al</strong>-<strong>Flux</strong> <strong>7028</strong>E paste is used extensively in the cookware industry to join aluminium bases<br />

to stainless steel pots.<br />

<strong>Al</strong>-<strong>Flux</strong> <strong>7028</strong>:<br />

– CAB flux (<strong>Al</strong>-<strong>Flux</strong> 2805)<br />

– <strong>Al</strong>Si12 <strong>Filler</strong> metal<br />

– Inorganic carrier system<br />

– Cesium complex can be added<br />

Process:<br />

Application:<br />

– Spray<br />

– Dispense<br />

– Dip<br />

– Brush<br />

Brazing:<br />

– Controlled Atmosphere Brazing (CAB)<br />

– Induction<br />

– Indirect flame<br />

Benefits of <strong>Al</strong>-<strong>Flux</strong> <strong>7028</strong>:<br />

- Cost competitive product<br />

- Improved process<br />

- Reduced inventory<br />

- Balanced flux to filler metal ratio<br />

- Excellent braze fillet formation<br />

Conclusion:<br />

Capillary tube brazed to pipe using<br />

<strong>Al</strong>-<strong>Flux</strong> <strong>7028</strong>E<br />

Excellent braze fillet formation<br />

Photo 3: Coated And Un-Coated Evaporator Plates<br />

<strong>Al</strong>-<strong>Flux</strong> <strong>7028</strong> flux pastes provide practical solutions for the application of filler metal in braze joints.<br />

Manifold to evaporator core brazing<br />

using <strong>Al</strong>-<strong>Flux</strong> <strong>7028</strong> E 45 Di<br />

Photo courtesy of Vulkan<br />

Manifold after<br />

indirect flame<br />

brazing<br />

FLUX GmbH is the leader in fluxing technologies and is continuously developing customer specific solutions to achieve<br />

maximum cost benefit in the processing sequence of heat exchange products. Issued 04/2011