What is Brazing? | Skill-Lync

Summary

This video from Skill Link delves into brazing, a fusion welding process distinct from traditional welding as it melts only the filler metal, not the base metal. It explores various brazing methods: torch brazing with a controlled flame, furnace brazing for mass production, dip brazing using molten baths, and braze welding focusing on filler metal joints. Advantages include joining dissimilar metals and automating high-volume production. However, brazing has limitations like lower joint strength and aesthetic mismatches due to different metal colors.

Takeaways

• 🔥 Brazing is a fusion welding process where only the filler metal melts, not the base metal.
• 🌡️ The filler metal in brazing has a melting temperature above 450°C but below the melting point of the base metal.
• 🔧 Torch brazing involves applying flux, using a torch to heat the joint, and adding filler wire once the temperature is suitable.
• ⚙️ Furnace brazing is ideal for mass production and requires parts and filler metal to be heated in a furnace to the brazing temperature.
• 🍲 Dip brazing uses a molten salt or metal bath for heating, with the workpiece immersed to fuse joints by capillary action.
• 🧰 Braze welding is similar to gas welding but only the filler metal forms the joint, as the base metal doesn't melt.
• 🤝 Brazing allows joining of any metal, including dissimilar metals, which is not always possible with conventional welding.
• 🏭 Some brazing methods, like furnace and dip brazing, can be automated for high production rates.
• 🔩 Brazing is suitable for joining thin parts that cannot withstand the heat of welding, such as through infrared brazing.
• ⚖️ While brazing has several advantages, the joints created are generally less strong than welded joints and not suitable for high-temperature operations.

Q & A

What is brazing and how does it differ from other welding processes?

Brazing is a type of fusion welding process where only the filler metal is melted, not the base metal. It differs from other welding processes where both the base metal and the filler metal are melted together.

What is the melting temperature range for the filler metal used in brazing?

The filler metal used in brazing has a melting temperature above 450 degrees centigrade but below the melting point of the base metal.

What are the various types of brazing mentioned in the script?

The script mentions torch brazing, furnace brazing, dip brazing, and braze welding as the various types of brazing.

How is torch brazing performed and what is its significance?

Torch brazing involves applying flux to the surfaces, using a torch to direct a flame towards the joint, and adding filler wire once the joint areas reach a suitable temperature. It is significant because it allows for manual control over the process, which is crucial for achieving a proper joint.

What type of flame is typically used in torch brazing and why?

An oxygen-starved flame is typically used in torch brazing to prevent oxidation on the workpiece.

What is furnace brazing and in what type of production is it suited?

Furnace brazing uses a furnace to supply heat for brazing and is suited for medium to high production rates, often used for mass-producing parts.

How does dip brazing work and what are its advantages?

Dip brazing uses a molten salt bath or a molten metal bath as a heat source, where the workpiece and the brazing metal are immersed. The advantages include faster fusion of joints and the ability to join multiple joints at once.

What is the difference between braze welding and gas welding?

In gas welding, both the base metal and the filler are melted and fused together, whereas in braze welding, the joint consists only of filler metal since the base metal does not melt.

What are some advantages of brazing compared to welding?

Brazing allows joining of any metal, including dissimilar metals, and can be performed quickly and consistently for high production rates. It also requires less heat and power than most fusion welding processes.

What are the disadvantages of brazing as mentioned in the script?

The disadvantages of brazing include weaker joint strength compared to welded joints, inability to join components required for high-temperature operations due to the low melting temperature of brazing metals, and potential aesthetic issues due to color mismatch between the brazing metal and the base metal.

What is the role of the worker's skill in torch brazing?

The worker's skill is crucial in torch brazing as they must control the flame, manipulate the handheld torch, and properly judge the temperature to ensure a proper joint is obtained.