Which grades of silver braze filler metal are typically used by a heat treater in the navy?

The choice of Grades 3, 4, and 5 as the typical silver braze filler metals used by heat treaters in the navy is based on their properties and applications. These grades contain a specific percentage of silver, along with other alloying elements that enhance their mechanical properties and resistance to thermal and oxidation stresses.

Grade 3 is known for its good fluidity and is effective for joining dissimilar metals, providing strength and ductility in the joint. Grade 4 has a higher silver content, which improves its properties even further, making it suitable for high-stress applications. Grade 5 is often used for its strength in harsher environments, which is critical in navy applications where durability and reliability are paramount.

Using these grades in a military context ensures that the joints formed are robust, can withstand extreme conditions, and maintain structural integrity during operation. The heat treating process requires a filler metal that can endure thermal cycles and mechanical stresses without degrading, making these three grades a suitable choice for the navy's needs.