Effects of the Grain Size on the Cellular Precipitations in Cu-Be and Cu-Ni-Sn Alloys

Effects of the grain size on the nucleation and growth of grain boundary cells in Cu-2%Be and Cu-10%Ni-8%Sn alloys were investigated by the quantitative metallographic method. The nucleation of the cells was suppressed with increase in the mean grain size. The maximum growth rate of cell at the early stage of aging depended on the mean grain size and was maximum in the specimen with intermediate grain size, 160 μm in the Cu-2%Be alloy and 110 μm in the Cu-10%Ni-8%Sn alloy. The mean growth rate of cell was also dependent on the grain size, but the degree of its dependence was not so remarkable in comparison with that of the maximum growth rate of cell. The volume fraction of the cell decreased with increase in the grain size. The nucleation and growth of cells in the Cu-10%Ni-8%Sn alloy were more remarkably influenced by the grain size in comparison with those of the Cu-2%Be alloy.