Properties of Tin Bronze

Bronze containing 3% to 14% tin, in addition, phosphorus, zinc, lead and other elements are often added. It is the earliest alloy used by human beings and has a history of about 4,000 years. It is corrosion-resistant, wear-resistant, has good mechanical properties and process properties, and can be welded and brazed well, and does not produce sparks when impacted. Divided into processed tin bronze and cast tin bronze. Tin bronze is a non-ferrous metal alloy with the smallest casting shrinkage, and can be used to produce castings with complex shapes, clear outlines and low air tightness requirements. Tin bronze is very resistant to corrosion in the atmosphere, sea water, fresh water and steam, and is widely used in steam boilers and marine ship parts. Phosphorus-containing tin bronze has good mechanical properties and can be used as wear-resistant parts and elastic parts of high-precision machine tools. Lead-containing tin bronze is often used as wear-resistant parts and sliding bearings, and zinc-containing tin bronze can be used for high air tightness castings.

The solidification range of tin bronze is large, and the dendrite segregation is serious; it is not easy to form concentrated shrinkage cavities during solidification, and the volume shrinkage is very small; the reverse segregation of tin is prone to occur in the ingot, and white spots (8-phase precipitation) can be seen on the surface of the ingot in severe cases. There are even tin-rich particles, commonly known as tin sweat. Improving casting methods and process conditions can reduce the degree of reverse segregation; in liquid alloys, tin is prone to form hard and brittle inclusions SnO2, and smelting should be fully deoxidized to prevent alloys caused by inclusions. Decreased mechanical properties; very little sensitivity to overheating and gases, good for welding and brazing.