Silver imparts special properties to aluminum alloys. It's addition to aluminum has provided the strongest cast aluminum alloy known, now used to advantage in aircraft such as the Air Force C17 transport and in the Army's Apache helicopter. It has been used on several of the NASA space shuttle missions. Seals together the radar tubes now being installed at US airfields to warn pilots of deadly wind shear. Silver has also long been used to braze materials together.
Silver has a unique affinity for oxygen.
This property is critical to high temperature superconductors, which will revolutionize the transmission and storage of electrical power and the efficiency of motors and most other electrical equipment. In this application, silver not only prevents the loss of oxygen, but also acts as a source of nascent oxygen, essential to the operation of the superconductor. When silver is sintered with superconducting materials, the silver matrix itself displays superconducting properties. Silver is also a powerful oxidative catalyst for the chemical process industry. A worldwide inventory of some 30 million ounces of silver are in daily use for catalytic oxidation in it's chemical reactors.