A comparative study on effects of special casting processes on microstructural development in Cu-(10)Al-4Fe-4Ni alloy

摘要

Suction casting (SC) and centrifugal casting (CC) are two common special casting processes. The influences of SC and CC on the microstructural development of Cu_(10)Al_4Fe_4Ni aluminum bronzes were investigated with continuous cooling method. The results indicate that α, β', K_Ⅱ, and K_Ⅲ phases are observed in the quasicast microstructure via the SC process with the precipitation sequence of K_Ⅱ→α→K_Ⅲ. Additionally, K_Ⅰ and K_Ⅳ are observed in the quasicast microstructure via the CC process with the precipitation sequence of α +K_Ⅰ→K_Ⅱ→K_Ⅳ→K_Ⅲ. Phase initial precipitation temperatures of the CC process are higher than that of the SC process, especially for α phase. As the quenching temperature decreases, the hardness of both alloys shows a rapid decline trend and finally reaches a steady state. It is found that the eutectoid decomposition (β→α + K_Ⅲ) barely affects the hardness of the alloys.