In our previous articles, we introduced the Vacuum Brazing of Aluminum Alloys and Brazing Materials. Today we will talk about Vacuum brazing of aluminum alloys and changes in brazed Joints strength.
Vacuum brazing of aluminum alloys and changes in brazed joints strength
vacuum brazed joints strength test
When brazing aluminum alloys, Mg2Si can easily appear, which enhances the strength of the brazing joints. In the process of brazing heat treatment, the brazing is also subjected to solution and aging treatment. In order to grasp the changes in strength during this process, strength experiments should be conducted on the brazing.
Experiment, first according to the requirements of the “former brazing head strength test method” (GB/T11363-2008), the corresponding experimental device, the device material BAl88Mg. After the completion of the brazing process, the entire device will be divided into two parts, one part without treatment, the other part placed in the solid solution at 515 ℃, 120min environment, and the way to 170 ℃, 480min environment for aging treatment. The results of the experiments are shown in Table below. From the table, it can be found that the strength of the heat-treated aluminum alloy is significantly increased compared to that of the brazed state.
| Alloy | Test | Tensile Strength (Mpa) | Shearing Strength (Mpa) |
| 6061 | Brazing
Heat treatment |
109.2
251.6 |
46.5
68.4 |
| 6063 | Brazing
Heat treatment |
86.5
228.8 |
34.9
65.6 |
Metallurgical analysis
The images of heat-treated 6061 and 6063 aluminum alloys were taken using an optical microscope, and it can be seen from the images that the strengthening phases are more uniformly distributed in the heat-treated images than in the pre-brazed images, but there is still an enrichment of Si and Mg in the brazing area. It can be seen that the heat-treated aluminum alloy has higher strength.
Conclusion
In summary, the 6061 and 6063 aluminum alloys are able to reduce the tensile strength by more than 60% after vacuum brazing. After brazing + aging treatment, the tensile strength of the aluminum alloy can be effectively improved to about 80% of its normal state, and the strength of the brazing joints is obviously improved, which fully meets the current requirements of electronic equipment for aluminum alloy materials.
Check out our Vacuum Brazing Furnace in detail.
More Vacuum Heat Treatment:
- Vacuum Heat Treatment and Aluminum Processing (1): the defects of traditional vacuum annealing technology
- Vacuum Heat Treatment (1): what is vacuum heat treatment, the feature, how to choose…
- Vacuum Heat Treatment (2): How to choose the vacuum heating temperature and heating time?
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