The transformation behavior of Cu-8.0Ni-1.8Si-0.6Sn-0.15Mg alloy during isothermal heat treatment

► TTP curves have been established and their nose-tip temperatures are about 650 °C. ► Discontinuous precipitation appeared during isothermal treated at 550 °C. ► Continuous precipitation appeared when temperature is below 550 °C and above 650 °C. ► Crystal orientations relationships are: (02¯2¯)Cu‖(01¯1¯)β‖(010)δ, [100]Cu‖[100]β‖[001]δ;(02¯2¯)Cu‖(01¯1¯)β‖(100)δ ′, [100]Cu‖[100]β‖[001]δ ′.