copper-silver softening resistance

Silver in copper acts as a grain refiner and stabilizes the microstructure. But if you have too much silver in it, the microstructure can become coarse and brittle, which then causes cracks and corrosion. When welding, you must be careful not to overheat the alloy and to keep the melt short, otherwise the silver burns out and the microstructure deteriorates. Weld the whole thing under shielding gas, then the alloy stays clean.