Influence of Solution-Treatment Conditions on the Cellular Precipitation in Si-Doped Cu–10Ni–8Sn Alloy

The influence of solution-annealing conditions (temperature and time) on the nucleation and growth of grain boundary cells in the 0.2%Si-doped Cu-10%Ni-8%Sn alloy on aging at 723 K was investigated by the quantitative metallographic method. The hardness change in the matrix during aging at 723 K was scarcely affected by the solution-annealing conditions. However, the nucleation and growth of the cell during aging was remarkably affected by the solution-annealing conditions. When the solution-annealing temperature or time was increased, the suppressing effect of Si on the cellular precipitation was decreased. The Ni31Si12 phase particles which existed in the matrix grains and grain boundaries in the as-quenched specimen were coarsened with increasing solution-annealing temperature or time. Therefore, it is suggested that in the specimen solution-annealed at a higer temperature or for a longer time, the effects that the Ni31Si12 phase particles occupy the nucleation sites of the cells in the grain boundaries and suppress the migration of the advancing boundaries of the cells on aging were decreased.