1. Definition and Background
　　Cyanide free copper tin alloy refers to a copper tin alloy that does not use cyanide containing plating solutions or raw materials during electroplating or production processes. Traditionally, copper tin alloy electroplating often uses cyanide containing plating solutions, but these plating solutions are highly toxic and not conducive to environmental protection and human health.
　　2. Research and application
　　At present, research on cyanide free copper tin alloys mainly focuses on systems such as pyrophosphate and citrate. The main difference between these systems and cyanide copper tin alloy electroplating lies in the alloying method and current density.
　　Cyanide free copper tin alloy plating solutions have been successfully used in production, such as pyrophosphate tartrate plating solutions. In addition, various cyanide free plating solutions such as tartaric acid stannate and citric acid stannate have been developed.
　　The cyanide free copper tin alloy coating may appear dark in color, which is different from the cyanide coating (which is whiter and has better brightness).
　　3. Application Fields
　　Cyanide free copper tin alloy is widely used in fields such as coin casting and anti-corrosion of mining machines due to its excellent corrosion resistance and hardness. Meanwhile, with the increasing demand for environmental protection, its potential for application in fields such as electronics, communication, aerospace, etc. is gradually increasing