Identifying and understanding the differences between brazing and welding is the first step in determining which process is best for your application. Until we understand which option provides the best strength, reliability, and performance, then we can decide which process will produce the best quality joints. Factors to consider start with what the application demands based on the environment it will be subjected to and the material selections that ensure the system functions as designed.

Elcon Precision has a wealth of experience in this critical aspect of the process, built on a foundation of producing high-performance assemblies that meet and exceed both the functional demands required as well as the quality assurance to support it. Our clients count on Elcon's decades of experience in advanced metal and ceramic joining techniques that produce strong, reliable joints. We are a leader in precision manufacturing, specializing in advanced metal and ceramic joining techniques, including brazing and welding, providing tailored services and solutions for even the most complex manufacturing challenges.

Fundamentals of Welding and Brazing

From a high level, brazing and welding follow similar principals, with a handful of very distinct differences that can help quickly determine which option is not only best but actually feasible for the design on the drawing board. Welding is a process most are more familiar with, whether it be steel beams welded together to create the framework of a skyscraper structure or the chassis all cars are supported by that we drive throughout our everyday lives. Brazing is also something most have at least surface-level knowledge about, like the copper pipes for the condensers in our AC units or if we want to repair or divert a water line that's been corroded over time. The major difference between the two is far more significant than the end result, which for both, is to join materials together creating strong material bonds to create a singular system that functions as though it was all made from a single piece of material.

The Basics of Welding

Welding is a cornerstone of the fabrication process, as well as a large contributor to the trades professions as it spans multiple disciplines and a vast number of industries and applications. It has grown into a critical fabrication process that supports basic designs, all the way through the most rigorously demanded sectors that require some of the most experienced metal crafters in the world.

There are a handful of standard techniques that provide the most optimal conditions to create the strongest joints possible, all of which require specific parameters in order to be effective. Raw material as well as filler metal material play a crucial role in determining which method will provide the best results, as well as which method is even possible, given the materials used and what demands the application has for strength and precision. The heat generated throughout each welding process also plays a significant role in which method is best, as some materials are far less resistant to constant heat than other materials.

Arc Welding - The traditional primary methods:

Shielded Metal Arc Welding (SMAW), also known as stick welding, uses a consumable electrode coated in flux.
Gas Metal Arc Welding (GMAW), also known as MIG welding, uses shielding gas along the electrode, preventing contamination within the weld.
Flux-Cored Arc Welding (FCAW), similar to the process of MIG, but instead uses a tubular wire filled with flux.
Gas Tungsten Arc Welding (GTAW), more commonly known as TIG welding, uses a non-consumable tungsten electrode and is often used for joining thin materials.

Resistance Welding - The traditional secondary methods:

Spot Welding is used to join thin metals by applying current and pressure through a specific spot to weld.
Seam Welding is applied the same way as spot welding, by rolling the electrodes along the joint to form a continuous seam.

Gas Welding - The original method:

Oxy-Fuel Welding (OFW), burns a controlled mixture of oxygen and gas (like acetylene) to melt the metals together.

Energy Beam Welding - The technologically advanced methods:

Laser Beam Welding (LBM), typically used in high-precision robotic welding for repeatability using high-powered lasers.
Electron Beam Welding (EBM), typically created in a vacuum environment with a concentrated beam of electrons, focused on a particular area to join them.

Solid-State Welding - The not-so-common, but very particular methods used:

Friction Welding, just as it sounds, generates heat through mechanical friction to join metals.
Ultrasonic Welding, high-frequency, focused ultrasonic vibrations used to join metals.

The Basics of Brazing

Brazing has a much deeper history when it comes to its first known discovery, dating all the way back to 3000 BC, possibly earlier, where the method was used to create intricately designed jewelry using gold and copper for the Pharaohs. The process involves a balance of melting and introducing a filler metal into a joint between two parts without affecting the base material. The filler metal typically has a lower melting point than the base metals, and is often silver, copper, or aluminum, due to the softer mechanical properties and relatively low melting point. The process involves heating the filler metal past its melting point and then allowing it to cool evenly to create a solidified bond between the pieces of material.

Brazing relies on flux to enhance the strength and mechanical properties of base materials by:

Removing oxides formed during heating.
Promoting effective wetting of the base metal.
Supporting capillary action to pull molten alloy into the joint.

Brazing is most commonly used in the automotive, aerospace, and HVAC industries, given its high-strength bond and increased corrosion resistance due to not affecting the base material surfaces. The brazing process also reduces thermal distortion due to the melting point of the filler material being lower than the base material. Additionally, a major benefit of brazing comes with the ability to join dissimilar metals as well as joining different materials altogether, like ceramic to copper.

Optimizing Flux and Filler Metal

Achieving the right balance of flux and filler metal is critical for a strong, reliable joint. Too little or too much of either can weaken the joint. Our experienced engineers and technicians carefully control this process to ensure the creation of a strong, hermetic seal. Following brazing, we perform a range of in-house tests to verify the integrity of the joint.

Types of Flux

Fluxes come in a variety of forms, including solids, powders, pastes, rings, washers, and sheets. Elcon’s photochemical etching services can precisely etch these rings and washers for use in brazing applications.

Joint Spacing for Brazing

Brazing requires precise joint spacing to facilitate capillary action. The proper gap ensures that the filler metal is drawn into the joint when the parts reach the required phase temperature, resulting in a solid bond. Our engineers will help design component drawings to account for ideal joint spacing.

Vacuum Brazing:

As it sounds, this process takes place in a vacuum chamber, preventing oxidation and contamination. It's ideal for high-purity and high-strength joints, often used in aerospace and medical applications.

Torch Brazing:

Commonly used for small-scale repair work, this technique uses a hand-held torch to heat the workpieces and the filler metal.

Furnace Brazing:

This involves heating the assembled parts in a controlled atmosphere furnace. Ideal for high-volume production and precision temperature control for uniform heating.

Induction Brazing

This method uses electromagnetic induction to heat the workpieces. Fast, efficient, and well-suited for joining small or localized areas.

Dip Brazing:

The parts are immersed in a molten salt bath or flux bath, which serves as both the heat source and flux. Often used for aluminum and other non-ferrous metals.

Resistance Brazing:

Electric resistance heating is used to melt the filler metal. This method is suitable for precise, small-scale applications and offers better control of the heating process.

Infrared Brazing:

Uses infrared radiation to heat the parts and filler metal. Commonly used for delicate or heat-sensitive components.

What's The Difference?

Both brazing and welding involve melting materials to join them together, however, the fundamental difference is whether or not the base metal or materials are included in the melting process. Unlike welding, brazing does not involve melting the work pieces.

The main difference between brazing and welding is the heat source. Brazing is applied via torch, furnace, induction, dipped or resistance as heat sources occur at a temperature above 840°F (450°C), whereas welding uses electricity as a heat source reaching temperatures of roughly 10,000 degrees Fahrenheit.

To weld or to braze ultimately comes down to a few primary pillars during the design phase. In no particular order, materials used, strength required, and production volume, all of which determine cost, which is more often than not, the primary variable when it comes to design feasibility. Both welding and brazing processes offer advantages depending on the method chosen and the materials being used, but more often than not once the primary method is chosen, the difficult part is sourcing a reliable partner you can depend upon.

Advantages and Limitations

There is a critical point in which the design will shift towards either welding or brazing; this is a culmination of application requirements based on the materials being used and the potential stress the bonded or joined surfaces will be subjected to during operation. Below are key points to consider when making your decision on what is best or otherwise more critical, for your specific application.

Material Type

Welding: Vast range of metals and alloys with high melting points. This is limited to metals with similar melting points.
Brazing: Better for joining dissimilar materials and metals for more complex assemblies. Ceramic to copper alloys for example, where the materials have different coefficients of thermal expansion, can be joined with furnace brazing.. Elcon’s ceramic metallization process prepares ceramics for subsequent brazing to metal components.

Joint Strength

Brazing and welding both result in strong joints. However, because the base metals are not melted during brazing, they retain their physical properties. In many cases, a properly brazed joint may be stronger than the base materials.

Heat Sensitivity

Welding: High temperatures that can lead to distortion or warping if not processed correctly.
Brazing: Uses lower temperatures for filler material, like copper brazing or silver brazing, which often don't affect the base material properties, as a result of less thermal stress during the metal joining process.

Precision and Cleanliness

Welding: Precision dependent, especially when using manual operations vs. robotic welding.
Brazing: Cleaner joints based on environmentally controlled environments, particularly in complex assemblies, one major benefit is reduced surface oxides and unaffected base metal surfaces. Because brazing occurs where parts’ joints are met, there is no post-processing or finishing after assemblies are brazed.

Cost and Equipment

Welding: Specialty equipment and personnel required for specialty processes; quality of work is highly dependent upon cost of labor.
Brazing: Specialty equipment required, but more affordable to operate and creates consistent quality brazed joints, becoming more cost-effective for certain applications over time. Post-processing or finishing of assemblies is usually not required.

Key Industry Applications

Relatively speaking, the end goal is the same whether you choose welding or brazing, create bonds and joints that withstand the environmental and rigorous conditions of the application, and adhere to the quality requirements of both the process and the materials being used.

The difference between brazing copper or brazing ceramics, or brazing any material for that matter, is based on the fundamentals. As long as you perform the process under the right conditions with proper heating and cooling cycles, the correct brazing materials, and the optimal environmental conditions, the brazing method to produce joints can withstand harsh conditions and mechanical stress.

The same can be said about the welding process, as long as you use the correct filler wires and filler rod, proper heating method, and consider your environmental conditions, producing quality joints and welds is easily achievable with qualified personnel and the right equipment.

Aerospace and Defense:

In most aerospace applications, more often than not you can choose whether you want to weld something together or just mechanically fasten components together using traditional nuts and bolts. Conversely, that is not typically the case when it comes to aspects of a design that require brazing, there isn't exactly a bolt or nut to use instead, mostly due to what is available on the market. Additionally, sometimes the size of the components and assemblies that require brazing are too small to accommodate anything other than precision brazing.

Most aerospace applications have a strict requirement when it comes to strength vs. weight, airplanes for example need to have the strongest possible joints but also keeping in mind weight reduction for the sake of fuel consumption as well as aerodynamics. Brazing is becoming a more popular option based on the versatility of materials as well as the reduced stress on the assemblies during the manufacturing process.

Medical Devices

The majority of medical devices typically require extremely rigorous environmental control as well as consistency in bonded materials. This often leads to traditional welding not being ideal for most medical device applications, given the general lack of cleanliness that comes with standard welding.

The other major considerations that bring brazing processes to the forefront are biocompatibility and size. Most medical devices have a strict requirement for biocompatibility and typically find themselves introduced or operated in tight spaces, like your ear for a hearing aid for example. Using materials that not only function properly but also work with human tissue is crucial in creating long-lasting, effective medical devices.

Electronics

Hermetic brazing for the electronics sector provides a multitude of benefits that are imperative to the success and consistent function of any given electronic connection that requires brazing. Producing an airtight seal and a completely leak-free connection is essential in providing protection to the electrical components from contamination like moisture or dust.

The end result is reliable performance and durability while also protecting sensitive components from corrosion over time. Even more so in harsh conditions, electronics undergo in the space industry, where materials like Kovar and ceramics are specifically chosen due to the ability to withstand the thermal expansion experienced during both the launch and environmental conditions subjected during orbit.

The Elcon Precision Distinction

Although the quality requirements are consistent across both welding and brazing, there is a fundamental difference between finding a welding partner and a brazing partner. Most of which comes down to the complexity of the application or design, as well as the environmental conditions required during the actual fabrication process that truly separates the two. Most manufacturing facilities have a weld operation in one area or another of the organization, and it's an add-on service to their core competencies like vertical machining or sheet metal fabrication.

Brazing on the other hand is very specific, and Elcon has built a reputation of being a high-precision brazing facility with a focus on complexity. We didn't just add brazing to our list of capabilities, we built our entire focus around it. We understood the need for a premier brazing partner and took the necessary steps in order to become and maintain that staple in the industry.

We've invested in the equipment and the personnel with a focus on the brazing industry in order to maintain a competitive edge for our clients, as well as offer them the top-notch service they expect from a supplier. We strive to provide the resources necessary for our client's designs to go from paper to physical product, and we are confident that if welding isn't the answer, we likely have a brazing process that is.

We've got decades of experience under our belt, and we back that up with our strict quality assurance program that includes measuring and testing tools to meet and exceed our customer's expectations. We invite continuous improvement to our facility and staff and maintain our commitment to quality parts through our AS9100 and ISO9001:2015 certifications.

Ready to Bond Together?

Knowing what key factors play into the decision-making process of choosing between brazing or welding during your conceptual phase is crucial. So, once you've picked compatible materials, determined the strength requirements where the system will see the most stress, and know the specifics of your application requirements for precision and reliability, you can confidently decide if brazing is the right choice. Don't necessarily have all the answers to those key topics? That's okay too, we've got a team of experts who are happy to help you make the most informed decision during one of the most critical aspects of your project, the design phase.

We've spent years cultivating our processes and combined that with the latest technology advancements and practices to support industry leaders across all major sectors. We truly believe that the first step in creating a quality part is by creating a quality partnership. Elcon Precision has, and will continue to be, a master innovator and your champion of brazing, no matter the complexity or precision demanded.

Elcon strives to ensure that each and every one of our clients is provided with the best option for their application and that regardless of the process chosen, we guarantee quality assurance is maintained throughout the process from start to finish. Whether your design is in the preliminary phase or already complete, we are here to help bring your project to fruition and completion.

Brazing vs. Welding: Which is Best for Your Application?