Our brazing is performed in accordance with FSD 5155 and MIL-B-7883.
Alumbra Stockholm is an approved contractor to F.M.V. (The Swedish Defence Materiel Administration) and the operators are certified in accordance with
FSD 5155 and FSD 5111.

Solderable alloys, example:
• Pure aluminium SS-EN 485-2
• SS 4104 AA 6063
• SS 4212 AA 6082 SS-EN 755-2

The solder used corresponds to AA 4047, AMS41858 and AWS BAlSi-4.
It contains Al and 12% Si (AlSi12) and has a melting interval between 575 and 582° C.
The solder has a high corrosion resistance.

The solderability is limited by the alloy content.
Recommended max levels:
• Mn 1,5%
• Mg 1,5%
• Si 1,5%
• Zn 6,5%
• Cu 0,5%

To achieve full strength in the base material after brazing it needs to be heat treated.
As the solder is not curable it is not affected in any significant way by this heat treatment.
The tensile strength, Rm, in the solder is 100-110N/mm²

The design process and the brazing process are based on our extensive theoretical knowledge and practical experience.
Documented examples include:
• Design of wide brazing-joints.
Normally solder joints of up to approx. 10mm are recommended but under the correct circumstances and with meticulous joint preparation we can successfully achieve joints of up to 25mm.
• Material effect during the process.
To get the right [moisture?] from the solder all components are cleaned and during brazing a fluxing of the surfaces is performed.
Together this creates a slight dimension change.
• The effect of cooling times the on strength of the material.
Cooling has a critical role in dictating the strength of the material.
• Evaluation of cleaning from salt from the component.
Comparative test with multiple methods.

Brazing oven 1200mmx800mm, depth 800mm.
Preheating oven diameter 1200mm, depth 800mm.
Cooling zone to control the rate of cooling.

Quenching oven
Heat treatment oven
Equipment for mechanical inspection
Tensile strength testing
Pressure testing

All chemical baths are regularly tested and analysed. The temperature in the salt baths is logged continuously in our PC based logging system.
The salt bath's solderability is regularly tested.
The removal from the components of residual salt post brazing is performed in controlled laboratory washing machines.