The tin bronzes differ considerably from the brasses insofar as relationship between thermal equilibria and actual structure in the cast condition. In true equilibrium an tin alloy would solidify entirely as a solid solution. In practice under normal casting conditions the wide freezing range causes extensive segregation to occur and the last liquid to solidify is so enriched in tin that it freezes by peritectic reaction at 798°Cto form B. On cooling further the B transfonns again.
Examining the binary Cu-Sn diagram in equilibrium there would be a series of eutectoid reactions where B would transform to a and y at 586°C (HIJ), then the y would transform to a and 15 at a temperature of 520°C (KLM) and finally the dlly the g the binary Cu-Snediagram in equilibrium there would be a series of eutectoid reactdons where B would >ranseorm to a and y at 586°C (HIJ), then the y would transform to a and 15 at a temperature of 520°C (K The d phase is an intermetallic compound Cu31Sn8 and is hard and brittle. The a+ d eutectoid is present as blue/grey phase evenly distributed in bearing bronze to give excellent wear resistance.