Phosphor bronze is a copper alloy that contains a significant amount of phosphorus. In addition to phosphorous, this type of alloy is also made with 3.5 to 10% of tin. This alloy is extremely well known for its durability, strength, low coefficient friction and fine grain. As a result of the phosphorus, this form of copper has great fluidity, when in a molten metal state, and subsequently has great castability.
In most cases, phosphor bronze is used for springs, bolts and other products that are designed to withstand fatigue, chemical corrosion, and high stress. It is highly common to find phosphorous bronze in marine based applications, because of their resistance to the aforementioned stressors. The alloy comes in a wide variety of grades and is commonly used as non-ferrous spring alloy. It is easily comparable to beryllium copper wire, which is a non ferrous alloy used for industrial applications. The main difference between the two alloys is the price tag; beryllium copper is much more expensive than phosphor bronze. Phosphor bronze is used in lieu of beryllium copper, when it isn’t explicitly necessary to use the stronger beryllium alloy. Phosphor bronze has combinations of attractive physical properties, electrical conductivity, and a moderate cost, which allows the material to be designed in a multitude of shapes and sizes. Manufactures will typically design phosphor bronze as springs, electrical contacts, or a wide variety of different wire forms.
It is also common to find Phosphor Bronze in the cryogenics industry. As a result of the alloys fair electrical conductivity and low thermal conductivity, it is able to function efficiently as an electrical connection, even in the presence of extremely low temperatures. For cryogenics, this alloy is perfect because it doesn’t need additional heat to function as an electrical component.
It is also common to find phosphor bronze in the spent nuclear waste field. When created with oxygen free copper, phosphor bronze can withstand oxidizing conditions, and become more equipped to withstand corrosion. Spent nuclear energy is extremely volatile and emits radiation over a long period of time. As a result, it is necessary to store the radioactive material in a container that will not erode over time.
If you have ever played a brass instrument, chances are it was created with some form of phosphor bronze. Trumpets, trombones, and saxophones are commonly designed with phosphor bronze, in order to achieve a certain look and sound.