The effect of silicon on the microstructure and properties of aged Cu-2.2Ni-0.4Be alloy

The effect of Si addition (0.2 wt%) on the precipitation evolution, mechanical properties and electrical conductivity of Cu-2.2Ni-0.4Be alloy were investigated, and the influencing mechanism was also discussed. The results show that Si can not only form delta phase with Ni, but also promote the nucleation and refine the size of NiBe phase, which increases the peak hardness from 282.3 HV to 308.2 HV. In addition, Si suppresses the NiBe phase coarsening under the over-aged condition, resulting in a much slower hardness and strength decline during the long time aging. Nevertheless, the electrical conductivity shows a slight decrease with Si addition, which is mainly attributed to the extra electronic scattering effect induced by the partial solution of Si.

Automated summary

The addition of Si can improve the mechanical properties and aging behavior of Cu-2.2Ni-0.4Be alloy, but it has a slight impact on the electrical conductivity.