ALUMUX – Aluminium Brazing Flux
Alumux* is a very potential aluminum brazing flux (* proprietary name of mathure fluxes) well suited for 5% and 12% silicon containing aluminum rods. It gives very good joints and good surface finish. It is used either in powder form or in paste form, where small portion of water is added to make a paste. It has very good fluidity and cleaning activity at about 585 º C. It’s physical properties are as follows.
APPLICATION:
Milk Can manufacturers, aluminum trays and utensils manufacturers, transformers, etc.
PHYSICAL PROPERTIES:
| Form | Powder |
| Colour | White |
| Solubility | 100% in Warm Water |
| Moisture | < 1.5% Highly Hygroscopic |
| Active Temp | 550 - 790º C |
| pH | 6 TO 8 |
TOXICITY:
This flux is very mild on human skin, however it is recommended to clean hands and part of body if it comes in contact with the flux. Fluxes being chemicals, precautions to be taken while handling.
HANDLING:
Recap the flux container after being used to avoid moisture absorption, as this flux is highly hygroscopic.
Fluxes are to be kept in closed air right containers when not in use.
Store in cool and dry place.
It is recommended to use fluxes within it’s expiry date.
Standard precautions to be taken during brazing operation
PACKAGING:
These fluxes are available in properly labeled containers in 250, 500. 1000 Gms. Pack.
TECHNICAL INFORMATION
Fluxes are mainly proprietary items, hence standards are not always specified. However it is essential to know whether a right type of the flux is being used in a required brazing / welding process. Following is information regarding brazing process:
It is a joining process where filler metal has a liquids above 425 º C, below that of the base metal and is distributed in the joint by the capillary attraction. Brazing processes are designated according to the sources of or methods of heating. E.g. Torch brazing, furnace brazing etc. Whatever may be the
method, fluxes play very important role in making leak proof sound joint.
Characteristics of Flux:
Dissolution of oxides formed and to remove dirt along with oxides, a cleaning function
Flux is an indicator of temperature indicating application of filler metal as it is melting prior to filler metal. It is a special feature of flux in torch brazing.
Flux helps to reduce surface tension which increases wet ability of the filler metal and promotes strong joint by capillary action.
Viscosity of the molten flux must be adequate to be readily displaced by molten filler metal.
In the process of torch brazing colour of the flame and gasses involved in process are also of prime importance from the health and safety aspects of the operat
Fluxes are usually applied in powder, paste or liquid form depending on requirement of a job extra flux and slag are removed after brazing by acidulated water, and rinsing by water thereafter.
Methods of inspection:
In most cases non-destructive methods are used to test braze joints as:
Visual examination in case of simple joint.
Proof testing – loads are applied to test a joint.
Pressure testing – for joint where gas or liquid tightness is required.
Vacuum testing – generally employed in checking assemblies used in refrigeration equipments and appliances. Other methods such as radiography, electrical resistance, ultrasonic inspection, thermal heat transfer inspection etc are also used.