High strength, high conductivity and excellent softening resistance Cu-Ni-Fe-P alloy

This article provided a detailed study on the evolution of microstructure and properties of Cu-Ni-Fe-P alloy during thermal mechanical process. The experimental results showed that the Cu-0.3Ni-0.3Fe-0.16P alloy had an optimal comprehensive properties of tensile strength (672 MPa) and electrical conductivity (69.2 %IACS). Through charactering microstructure by the TEM, the results showed that the ultrafine precipitates were (Ni, Fe)(2)P. The pre-aging sample had a higher tensile strength and electrical conductivity in the initial stage of the final aging because the pre-aging reduced the concentration of the dissolved Ni, Fe and P solutes in the Cu matrix and increased dislocations density during the subsequent rolling. The precipitation strengthening and dislocation strengthening were two main strengthening contributions to the Cu-Ni-Fe-P alloy. The high temperature softening resistance of Cu-Ni-Fe-P alloy was above 500 C-degrees. And the softening mechanism of Cu-Ni-Fe-P alloy was significantly associated with the coarsen precipitates and the recrystallization during the high-temperature annealing. This work provided a guiding significance for the development of high-strength and high-conductivity Cu alloys.