While you probably know that welding refers to the process of using heat, pressure, or fillers to join two or more materials, you might not know that there are several different types of welding processes. Each one has its own applications, advantages, and disadvantages.
There are two main types of welding: fusion welding and solid-state welding.
When materials are melted down in order to be joined together, that’s fusion welding. Any welding process that doesn’t involve melting is solid-state welding.
Heat is often still part of the process in solid-state welding. For example, it can be necessary to apply heat to get a solid joint, a reason that solid-state welding is sometimes called pressure welding. However, temperatures don’t reach the melting points of the materials being joined.
Advantages of Solid-State Welding
Solid-state welding makes it easier to join different types of metals. Also, because it doesn’t involve melting points, there’s less worry about distortion resulting, and the weld has a more elegant appearance. In addition, the heat-affected zone (HAZ) is smaller.
Disadvantages of Solid-State Welding
Solid-state welding requires a special edge preparation, joint design, or surface finish. Since some solid-state welding processes do not use filler metals during the welding process, these processes may not be able to fill a wide root gap, which is the minimum distance between the ends of the elements to be welded.
Types of Solid-State Welding
Several different types of solid-state welding exist.
- Cold Welding: This process doesn’t use heat or fusion at the joining point. Two metals that are similar to each other and clean are joined with high pressure. Cold welding works well with non-ferrous metals like aluminium and copper.
- Diffusion Welding: With diffusion welding, you can join both similar and dissimilar metals. It’s a relatively low-cost method and can produce high-quality joints and complex shapes.
- Explosion Welding: Explosion welding uses controlled detonation of explosive chemicals to create high-velocity movement of the parts to be joined, which leads to welding the materials together. It’s excellent for joining overlapping metal sheets, and it creates a permanent bond. Extensive knowledge of how to use explosives safely is required.
- Forge Welding: Forge welding uses heat and hammering to join metals together. The classic image of a blacksmith may come to mind here, and actually, forge welding was for centuries the only type of welding. It’s not only one of the oldest types of welding but also one of the simplest.
- Friction Welding: Friction welding, or friction stir welding, uses friction-generated heat to soften (but not melt) a metal. The softened metal is joined using a non-consumable tool. Since there’s no liquid phase, there aren’t worries about porousness, liquation cracking, and some other welding defects associated with fusion welding.
Friction welding also works well with a wide variety of metals and parameters. Because there are no toxic fumes or spatter, it’s also safer and more environmentally friendly than some other welding processes. - Roll Welding: Stacks of sheets or plates are fed through a cold rolling mill in roll welding. The process generates enough pressure to deform the stacks. Roll welding uses ductile metals such as aluminium, copper, alloys with the previous two, nickel, low carbon, and mild steel.
- Ultrasonic Welding: Typically used for welding plastics and dissimilar metals, ultrasonic welding involves high-frequency acoustic vibrations which cause friction at the point of contact of two materials. Due to heat generated by friction, this increases the temperature at the joining spot, which thus leads to joining the materials together at the point of contact. The aerospace, automotive, computer, electrical, and food packaging industries frequently use ultrasonic welding.
How Sustainment Can Help With Your Solid-State Welding Needs
When your business calls for one of the solid-state welding processes, where can you go? Do you know which welding type is best for the job?
Finding the right answers to those questions takes time, time that you can’t afford to lose since it can cost both productivity and money.
As a member of the Sustainment community, you’ll get recommendations from experts you can rely on. Our team uses its industry knowledge and experience to connect you with companies near you that can take care of your solid-state welding needs.
Save yourself time and hassle. Become a part of the Sustainment community today!
