Brazing and Welding are both processes used to join materials, but they differ in several fundamental ways. Below, we’ll outline the key distinctions between these two methods:

1. Temperature:

• Brazing: In brazing, the materials are joined at temperatures below the melting point of the base metals. Typically, the filler material (often a metal alloy with a lower melting point) is heated to a liquid state and then flows into the joint through capillary action.
• Welding: Welding involves melting the base metals being joined. This process occurs at temperatures above the melting point of the materials, resulting in a fusion of the base metals themselves.

2. Filler Material:

• Brazing: Brazing uses a separate filler material that is melted and flows into the joint. This filler material must have a lower melting point than the base metals.
• Welding: In welding, the base metals themselves are melted and fused together to form a strong joint. No separate filler material is necessary, although it can be used in some welding processes.

3. Base Metal Integrity:

• Brazing: Since the base metals do not melt during brazing, there is typically less risk of warping, distortion, or metallurgical changes in the materials being joined.
• Welding: Welding subjects the base metals to high temperatures, which can lead to metallurgical changes, distortion, and warping in the materials.

4. Joint Strength:

• Brazing: Brazed joints tend to be mechanically strong, but they may not have the same level of strength as a welded joint. However, they can be very reliable for many applications.
• Welding: Welded joints often provide higher strength compared to brazed joints due to the fusion of the base metals. This makes welding suitable for high-stress applications.

5. Joint Appearance:

• Brazing: Brazed joints are generally smoother and neater in appearance, as the base metals do not melt and form a clean joint.
• Welding: Welded joints can be more rugged in appearance due to the fusion of the base metals. The appearance of a weld can be influenced by factors such as welding technique and post-welding finishing.

6. Application Areas:

• Brazing: Brazing is often used for joining dissimilar metals, delicate or heat-sensitive materials, and in situations where precise control of joint appearance is required (e.g., jewelry-making, plumbing).
• Welding: Welding is employed in applications where maximum joint strength is crucial, such as in heavy industry, construction, and the fabrication of structural components.

Both brazing and welding have their distinct advantages and are chosen based on the specific requirements of the application, the materials being joined, and the desired Joint properties.