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ALF1224 flux is a
fine white powder consisting of a mixture of potassium fluroroaluminate salts
which is non-corrosive and non-hygroscopic. The flux of the highest quality and
consistency is produced under stringent process tolerances and a variety of
quality control procedures by alpha-braze.
The flux has a melting point range of 560℃ to
574℃, just
below the eutectic temperature of the Al-Si brazing alloy. The particle size
lies in the range of 1㎛ to
50㎛.
During the brazing process the flux dissolves the oxide layer on
aluminium and allow the filler metal to flow freely into the joints by capillary
action. After cooling, the flux residue remains on the surface as a thin
adherent film and is non-corrosive and non-hygroscopic. The flux does not
require post brazing treatment of the joint
area. |
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ALF1224 flux |
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DESCRIPTION |
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Chemical
Composition |
K
(%) |
28-31 |
|
AL
(%) |
16-18 |
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F
(%) |
49-3 |
|
Fe
(%) |
max |
0.03 |
|
Ca
(%) |
max |
0.2 |
Application tests |
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Si
(%) |
max |
0.05 |
▣ Brazing
test |
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Physical
Properties |
Apperance |
White
powder |
▣ Colour
test |
|
Density(20℃) |
2.8g/cm3 |
▣ Particles
test |
|
Bulk
density |
400-600g/l |
▣ Black residue
test |
|
Melting
point(℃) |
560-574
℃ |
Packing |
|
Solubility in
water |
Nearly
insoluble |
Paper durms with
nner PE bags. |
|
Particle
size(50%) |
2~10
㎛ |
25Kg net
weight. |
Applications |
|
- Automobil: Radiator, Oil cooler, Condenser, Evaporator, Heater
core, Accumulator assemblies. |
| - Household: Kitchen pans and pots, Kettle, Coffee machines, Iron,
Clothes dryers. |
BRAZING PROCESS
1.
Cleaning : the
surface to be brazed must be pre-cleaned to achieve a water wettable
surface.
2.
Flux application :
usually as a water based slurry. Typical the slurry concentration is in the
range of 3% to 25%.
3.
Drying : To
achieve a successfully brazed component it is essential that all water is
removed from the flux coating. A drying process is carried out at
approximately 180℃ - 250℃.
4.The
process requirement of brazing furnace:
- Inert atmosphere - usually nitrogen as this is the cheapest.
- Dewpoint less than minus 40°C.
- Operating temperature range
of 575-620°C, coinciding with the melting point of the
cladding.
- Rate of heating of the component greater than 20°C per
minute.
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Aluminium brazing furnaces |
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Fluxing |
Drying |
Brazing
furnace |
Cooling
chambers |
Final
cool |
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| Aluminium brazing Flux: |
Aluminium brazing Flux Cored Wire: |
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non corrosive flux, corrosive flux. |
Product cored ready for use containing non corrosive
flux. |
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Aluminium brazing Paste:
Product in paste ready for use containing aluminium brazing
powder, non corrosive flux and binder.
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Aluminium brazing Powder: |
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Al/Si, Al/Zn alloy powders.
Also available in wires, rods,
rings |
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