Brazing is an effective method used to join metal parts and there are many important aspects that must be taken into account in order to be completed successfully. Here are the detailed elements you need to consider when starting the brazing process:
1. Gap Check: How Much Should It Be?
Controlling the clearance between parts during the brazing process is critical to the strength and quality of the joint. The ideal clearance should generally be between 0.05 and 0.15 mm, but this value may vary depending on the application and part geometry. Gap control must be carefully calculated during the design and production phase of the parts. Additionally, the uniform distribution of voids is also important and can help prevent unwanted deformations after brazing.
2. Effect of Cleaning and Contamination
Cleaning the surface of the parts before brazing is critical. Oil, dirt, or oxide layers on the surface may prevent the filler metal from spreading adequately or cause poor connections. Therefore, before starting the brazing process, the parts must be thoroughly cleaned and the oxides on the surface must be removed. Suitable solvents or mechanical cleaning methods can be used for cleaning. Additionally, the sensitivity and chemical compatibility of the parts to the materials used in the cleaning process should also be taken into consideration.
3. Brazing Position: Must Be Upright
The position of the parts during the brazing process is a critical factor to ensure proper flow of filler metal by capillary action. Parts can generally be positioned vertically or horizontally, but the upright position is generally preferred. In this way, the flow of the filler metal towards the seam is facilitated under the effect of gravity and a homogeneous connection is obtained. The upright position also ensures that the parts remain stable during the brazing process and that the filler metal flows into the correct gap. In horizontal positions, the flow of filler metal may sometimes be difficult and additional fixturing may be required.
Brazing Wire Orientation: Top to Bottom
The flow direction of the solder wire is also important during the brazing process. Generally, it is preferred for the solder wire to flow from top to bottom. This method allows the filler metal to properly flow by gravity into the gap between parts, creating stronger connections. Top-down flow can also help distribute the filler metal uniformly and cause less deformation in post-brazing operations.
Capillary Effect: What is it and why is it important?
The capillary effect is an important phenomenon that allows the filler metal to be drawn into the gaps between the parts during the brazing process. This effect enables the filler metal to spread homogeneously and form a strong connection, even in small gaps between parts. Without capillary action, it may be difficult for the filler metal to flow sufficiently and for the connection to have the desired strength. Therefore, correct positioning of the parts and meticulous clearance control during the brazing process ensures effective use of the capillary effect.
Bonus: Self Fixturing: A Practical Approach to Gap Control
The self-fixturing method is a practical approach that facilitates gap control during the brazing process. In this method, the parts are placed in the correct position by their own weight and the effect of gravity, so no additional external fixture is required. Self fixturing is especially useful in free fall or low precision applications and saves labor and costs.
We have examined these important elements that you should pay attention to before starting the brazing process. Factors such as gap control, cleanliness, correct positioning and capillary effect will enable you to create strong and durable connections. By meticulously applying each step during the brazing process, you will be able to achieve the quality and strength you want. For a successful brazing experience, it is vital to understand the process and take the right approach at each stage. Any difficulties you may encounter in practice can be solved by remembering these basic principles and you can ultimately ensure a more robust production.
Which is the most important issue in your opinion?
Cleaning
Brazing Position
Gap Control
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