Welding is commonly used to form a bond between 2 dissimilar materials (however, that isn’t always the case). There are forms of welding that bring materials to their melting points and uses filler metals to form a bond between them. The finished weld, once fully done will blend to be just as strong as the parent metal. Brazing on the other hand, uses a filler metal (alloy) to form a bond between two pieces of metal. Brazing is typically used to form a bond between dissimilar metals such as copper, silver, gold, and aluminum. Flux (a material that’s used to promote wetting) is also used during welding. It cleans parts of the oxides so the filler is able to bond more tightly to the metal parts.
Welding
What is Welding?
Welding joins metals by (typically) using high heat to form a bond between 2 materials (typically some form of metal). As the type of welding varies so will the use of shielding gas and consumable.
A few of the forms of welding that use shielding gasses are:
- TIG or GTAW
- GMAW
- GMAW-C
- Gas Shielded
- Flux Cored Arc Welding
Video credits to Kevin Caron, Artist. It discusses how to choose the right shielding gas.
Some forms of welding use filler metals to form bonds between 2 materials (again, usually metal). Each of the forms of welding falls into their own separate categories as well.
Welding is an activity that’s vital to our infrastructure. Welding, unlike other metal joining processes typically melts the base materials together. Typically, a filler material is used inside of the joint which forms a pool of molten material which hardens to form a joint that can be stronger than the parent metal.
The different forms of welding are:
- Resistance Welding
- Spot Welding
- Seam Welding
- Projection Welding
- Upset Welding
- Flash Welding
- Shot Welding
- Gas Welding
- Oxy-Fuel Welding
- Arc Welding
- Shielded Metal Arc Welding
- Manual Metal Arc Welding
- Flux Cored Arc Welding
- Gas Tungsten Arc Welding
- Tungsten Arc Welding
- Submerged Arc Welding
- Atomic Hydrogen Welding
- Electroslag Welding
- Electrogas Welding
- Stud Arc Welding
- Solid-State Welding
- Ultrasonic Welding
- Explosion Welding
- Magnetic Pulse Welding
- Exothermic Welding
- High Frequency Welding
- Diffusion Bonding
- Cold Welding
- Roll Welding
- Induction Welding
- Co-Exothermic Welding
- Co-Extrusion Welding
- Friction-Stir Welding
- Energy Beam Welding
- Laser Beam Welding
- Electron Beam Welding
- Laser Hybrid Welding
- X-Ray Welding
- Laser Cladding
What industries use welding?
Welding is typically used most in the:
- Automotive: Since MIG welding is typically used to deliver incredibly powerful bonds between thin metals and is ideal for joining sheets of metal on manufacturing lines.
- Aerospace: MIG Welding, Plasma Arc Welding, and Electrical Resistance Welding are all used in the Aerospace Industries. MIG Welding is used to build aircraft while PAW and Electrical Resistance Welding are used for joining sheeting and precision work.
- Construction and Infrastructure: MIG Welding, Plasma Arc Welding, and Flux Cored Welding are all used in construction and infrastructure. MIG Welding helps join non-ferrous metals and steel in the construction industries. Flux Cored Welding is also used alongside Plasma Arc Welding.
- Manufacturing: Because MIG Welding is known for it’s cost-effectiveness and speed which makes it great for high-output manufacturing.
- Railroads: Shot Welding, and innovative form of spot welding is used for the effective fusing of steel.
- Shipping: Welding is used in the development of most ships, from large tankers to cargo ships / aircraft carriers.
industries.
Brazing
What is Brazing?
Brazing is a metal joining process where metals are joined together by melting / flowing filler metals into a joint. The filler metal used in brazing has a lower melting point than that of the parent metals.
Brazing doesn’t melt the adjoining metals used in welding. The filler metals flows into the gaps left between the close-fitting parts via capillary action. It is then brought slightly above its melting temperature while also being protected by a suitable atmosphere. This filler metal then flows over the base metal and is cooled to join both pieces together.
What are the forms of brazing?
There are a few forms of brazing, each of which is below:
- Furnace Brazing: Furnace brazing is a semi-automatic process that’s typically used in industrial brazing operations because of it’s adaptability to be used for mass production and ability to be used by unskilled labor. A few advantages of furnace brazing are:
- It can produce large numbers of small parts easily
- It offers a controlled heat cycle and no need for post braze cleaning.
- Vacuum Brazing: Vacuum brazing is a joining process that yields various advantages. For example it offers extremely clean, flux free, superior braze joints.
- Silver Brazing: Silver Brazing is brazing that uses a silver alloy-based filler.
- Dip Brazing: Dip brazing is well suited or brazing aluminum since air is excluded, which prevents oxides from being formed.
- Braze Welding: Braze Welding usually requires more heat than brazing does which is why it typically uses Acetylene or Methylacetylene-Propadiene gas fuel.
- Torch Brazing: Torch Brazing is a method of mechanized brazing that’s best used in small production volumes. The 3 categories of torch brazing are: automatic, machine, and manual brazing.
How to make sure the surface area is clean during brazing?
When you’re welding you want to make sure that your surface area is clean. The good thing about welding is that the surface area is cleaned by the heat that you produce when you start the welding process – so you don’t need to worry about that too much. However, when you braze you produce less heat so you need to worry more about the cleanliness of the surface area you weld on. The contaminants that aren’t cleaned off of the surface area form into a layer on top of the weld that often turns into a hardened layer that will get in the way of the bonding process.
Video credits to Lucas-Milhaupt. It discusses how to clean the surface of metals.
