Final answer:
Silver brazing is best done with joints designed to allow for capillary action, requiring a gap typically between 0.002 inches to 0.005 inches. This allows the brazing alloy to flow and fill the joint evenly when melted, which is crucial for a strong bond.
Step-by-step explanation:
Silver brazing, often referred to as a 'silver soldering', is a process used to join materials together, typically metals, using a filler metal alloy with a melting point lower than that of the base metals. The joints designed for silver brazing are best when they allow for capillary action. This means the joints should be closely-fitted, with a gap typically between 0.002 inches (0.05 mm) to 0.005 inches (0.125 mm) to enable the brazing alloy to flow evenly and penetrate the entire joint through capillary action when melted.
The success of the brazing process depends significantly on the design of the joint, the cleanliness of the surfaces to be joined, the flux used, and the control of the heating process. It is critical that the joint design maintains the proper gap tolerance throughout the brazing process. In addition, the use of a suitable flux is essential to remove oxides from the metal surfaces and to shield the surfaces from oxidation whilst being heated.