Effect of solid solution and aging process on microstructure and properties of Cu-1.4Ni-1.2Co-0.6Si alloy

Microstructure and properties of Cu-1.4Ni-1.2Co-0.6Si alloy after different solid-solution and aging treatment were studied. Microhardness and electrical conductivity of the alloy after solid-solution and aging treatment were analyzed. The results show that the microstructure of the as-cast alloy is characteristic of equiaxed grains and precipitates are observed in the deformed grains after hot rolling. Recrystallization and grain growth occurrs during the solution treatment. With the increase of solid-solution temperature, the amount of dissolving precipitates increases rapidly. The precipitates are all dissolved into the matrix when solution temperature is 975 . The matrix and precipitate phase (Ni2Si) in the Cu-Ni-Co-Si and Cu-Ni-Si alloys have the same structure and morphology. And the relationship between the matrix and precipitates is that: [001]Cu//[110]p, (010)Cu//(001)p; [112]Cu//[324]p, (110)Cu//(211)p. The optimum solution and aging process is solution-trented at 975 for 1.5 h, aged at 500 for 4 h. At this condition, the microhardness, electrical conductivity of the alloy is 232 HV and 49 %IACS, respectively.