Gas brazing is a process of joining two metallic workpieces by melting a non-ferrous filler metal between them at high temperatures. It is similar to arc welding but without the use of arc. Instead, a flame, a laser-beam, or an electric resistance is used to heat the parts until the filler metal melts and creates a fillet joint upon solidification.
Gas brazing is well-suited for components in which a liquid material fits very well and surfaces are inaccessible for soldering, welding, or glue. The process is commonly used in manufacturing of electronic components, medical instruments, and electronic packaging.
The advantages of gas brazing include:
· Good joint strength. The joint strength of a brazed joint is usually greater than the parent material. This makes the joint more durable and less prone to fatigue failure.
· Economical application. Gas brazing eliminates the need for expensive consumables and creates lower operating costs compared to welding.
· Low level of emissions. Unlike welding, gas brazing normally does not produce harmful emissions. This makes it suitable for a wide range of applications where hazardous emissions must be avoided or minimized.
· Prevent oxidation. The shielding gas used in gas brazing helps to create an inert environment that limits oxidation and reduces the risk of discoloration.
· Reliable and precise joining. Gas brazing produces reliable and consistent joints helping engineers to work with greater precision and establish close tolerances.
Gas brazing generally uses a filler metal in the form of braze alloy wires and rods. The most commonly used filler metals are copper-based alloys, aluminum-silicon alloys, and nickel-base alloys. To protect the brazing process from oxygen, an inert gas such as argon, helium, nitrogen, or hydrogen is used. The atmospheres used for brazing are usually unbounded from external sources, meaning that the curing processes are performed in a controlled production environment.
The main applications of gas brazing include bonding electronic components, medical instruments, aluminum, stainless steel, and heat exchangers. The process can also be used to bond dissimilar materials such as aluminum and steel. Gas brazing equipment can be divided into a few categories: portable, stationary, and robotic.
Portable gas brazing equipment is smaller and cheaper than other types. It is well-suited for maintenance repair operations (MRO) and other applications where mobility is important.
Stationary brazing equipment can handle multiple components and vehicle assemblies. It requires major capital investments and requires specialized technicians to operate the machines. It is often used in industries that produce automobiles, aerospace parts, and other large-scale projects.
Robotic brazing equipment is highly automated and used for high-volume brazing and welding operations. It offers significant cost savings over stationary equipment because it requires fewer operators and less manual labor. However, it is more expensive to purchase.
Gas brazing can often be combined with other manufacturing processes such as welding, soldering, riveting, and machining. This allows for greater flexibility and cost-effectiveness for manufacturers.
Overall, gas brazing is a powerful and economical process for producing durable and strong joints and components. It is suitable for a wide range of industries, from automotive to electronics, and offers superior strength and reliability compared to welding and soldering. Its low-emission and ability to prevent oxidation makes it ideal for applications where emissions must be minimized or eliminated. Gas brazing is and will continue to be a solution in many industries where joining together two parts or components is important.
