What is the role of a heat sink in brazing?

• A. To absorb heat and slow heat transfer to control temperature, minimize distortion, and enable better capillary flow.
• B. To heat the joint faster.
• C. To remove flux chemically.
• D. To prevent solder from sticking.

Answer: (B)

A heat sink in brazing is used to control heat delivery by absorbing heat away from the joint area, slowing how fast heat spreads into the surrounding metal. This helps you bring the joint up to the brazing temperature without overheating adjacent sections, which reduces distortion and warping. By keeping the rest of the workpiece cooler, the temperature gradient at the joint is favorable for capillary flow, allowing the filler metal to flow into the joint more reliably. A heat sink doesn’t speed up heating, it doesn’t remove flux chemically, and it doesn’t prevent solder from sticking.