What does "fusion" welding involve when joining two materials?

"Fusion" welding specifically involves melting the base materials to create a strong bond. In this process, heat is applied to the parts being joined until they reach their melting point. As the materials melt, they flow together and, upon cooling, solidify to form a solid joint. This technique is foundational to many welding processes, including arc welding, MIG welding, and TIG welding, where the fusion of materials ensures the resulting weld is strong and capable of withstanding significant loads.

Other methods, such as using adhesives, heating without melting, or merely pressing two materials together, do not involve the same principles as fusion welding and typically do not result in the same properties of the joint. Each of those methods may be effective for specific applications but lacks the critical element of melting and solidifying the actual materials being joined, which is essential in fusion welding.