Difference Between Welding and Brazing

Brazing and welding are the two main techniques used to make robust, long-lasting metal joints.

There are several ways to link metal pieces together, such as adhesive bonding and mechanical fasteners. Still, there are usually two possibilities if you want to make strong, long-lasting metal joints: welding or brazing.

What is Brazing?

A brazed joint is created entirely differently than a welded joint. The temperature is the first significant change; brazing does not cause the base metals to melt. As a result, brazing temperatures are almost always lower than the melting points of base metals. For the same base metals, brazing temperatures are also considerably lower than welding temperatures, using less energy.

Brazing applications include electronics/electrics, airplanes, automobiles, HVAC/R, and more. Examples include automotive air conditioning systems, delicate jet turbine blades, satellite components, and beautiful jewelry. Applications requiring the joining of incompatible base metals, such as copper and steel, as well as non-metals like tungsten carbide, alumina, graphite, and diamond, benefit significantly from brazing.

What is Welding?

Metals are melted and fused during welding to unite them, usually with the help of a welding filler metal. The generated joints are strong, often stronger than the metals they join. You apply intense heat directly to the joint location to fuse the metals. To melt the base metals (the metals being joined) and the filler metals, this heat must be at a high temperature. As a result, welding temperatures begin at the base metals' melting points.

Large assemblies with two metal parts bonded in a single place and are somewhat thick (0.5"/12.7mm) are often best joined by welding. Since welded joints have an uneven bead, they are not used on items that need cosmetic joints. Applications span the fields of manufacturing, transportation, construction, and repair shops. Examples include the manufacture of pressure vessels, bridges, building structures, aircraft, train cars, and pipelines, in addition to robotic assemblies.

Differences Between Brazing and Welding

Brazing uses far lower temperatures and does not include melting base metals, whereas welding uses focused heat at the junction to melt and fuse metals. The alternative is to melt a filler metal and allow it to flow capillary into the junction. (Welding typically also incorporates a filler substance.)

The strength of the joint is frequently greater than that of the base materials when welding and brazing. However, brazing does not change most physical qualities and minimizes distortion, warping, and strain in the joint area since it uses less intense heat. In addition, brazing uses less energy because of its lower temperatures. Of course, the particulars of the application will ultimately determine whether to weld or braze.

Assembly Size

Welding is a reliable procedure to use when joining large assemblies. It can be challenging to braze large assemblies because of their propensity to spread heat. This makes it difficult to maintain the temperatures necessary for the filler metal to flow. In contrast, welding excels at joining large assemblies due to its concentrated heat and ability to trace a junction.

Thickness

Both procedures are reliable options when metal pieces are at least 0.5 inches thick and on the thick side. However, when it comes to narrow portions, brazing has the advantage. Such parts may distort or burn through due to the intense heat of welding. Brazing, on the other hand, can prevent deformation.

Joint Shape

While spot joints can be made by brazing and welding, welding can be quick and inexpensive due to localized heat. However, welding is less practical in linear joints because it necessitates manual tracing. Brazing also makes it simple to draw filler metal into various joint forms, including straight, curved, and irregular ones.

Material Types

When combining incompatible metals, brazing easily defeats welding. Brazing can provide robust joints with hardly any modification to the properties of the base metals. This is as long as the filler material is metallurgically compatible with both base metals and melts at a lower temperature. However, combining two different metals by welding requires complicated and expensive processes since the base materials are melted during the welding process.

Volume Of Production

Size, thickness, joint shape, and material concerns will influence your decisions when doing manual tasks. However, when part volumes reach hundreds or thousands, production methods and costs will take precedence. Both brazing and welding can be automated. However, brazing offers a wider range of automation options. When it comes to welding, you're typically left with two options: hand weld each component one at a time or use expensive, cutting-edge technology for lengthy runs. In contrast, medium-sized runs can be supported by brazing.

Appearance

Brazed joints are typically more appealing than welded ones, which have non-uniform beads and lack a crisp and discrete strip. After brazing, you rarely need to do any extra finishing procedures.