What happens to heat flow when filler metal is added?

When filler metal is added during a brazing process, the dynamics of heat flow in the joint area change significantly. The correct understanding is that heat flow is mainly influenced by the properties of the materials involved.

In the context of brazing, the introduction of filler metal doesn't stop heat flow; instead, it modifies how heat is distributed in the joint. Adding the filler metal can create thermal bridges or areas that either absorb or dissipate heat differently than the base materials.

The heat will continue to flow toward the areas that are cooler, which includes the new filler metal if it’s at a different temperature than the surrounding areas. This can lead to heat moving into the filler metal and away from the base metals, depending on their specific thermal properties and the configuration of the joint.

If the suggestion is made that heat flows in the opposite direction, it implies a misunderstanding of how heat transfer works in the context of brazing. Heat typically flows from the hotter areas to the cooler areas, so it wouldn't flow in an "opposite" manner.

Correctly understanding the effects of heat flow when filler metal is added can be critical for ensuring proper joint formation and achieving an effective brazed joint.