In braze welding, what happens to the parent metal?

In braze welding, the critical distinction is that the parent metal is not melted at all. Instead, braze welding involves using a filler metal with a melting point lower than that of the parent metals being joined. The parent metals are heated to a temperature that is high enough to melt the filler material but not enough to reach their own melting points.

This process allows the filler metal to flow into the joint and create a strong bond through capillary action, utilizing the liquid filler to connect the two solid parent metals without compromising their structural integrity. Because the parent metals do not experience melting, they maintain their original properties, which is essential for applications that require strength and durability in the joint.

The other options suggest varying degrees of melting the parent metal, which does not occur in braze welding. This technique is valuable in applications that require a strong joint without distorting or weakening the base materials.