Abstract

In this study, Cu-5Ni-10Sn(wt%) spinodal alloy was manufactured by gas atomization spray forming, and the microstructural features and mechanical properties of Cu-5Ni-10Sn alloy have been investigated during homogenization, cold working and age-hardening. The spray formed Cu-5Ni-10Sn alloy consisted of an equiaxed microstructure with a mixture of solid solution alpha-(CuNiSn) grains and lamellar-structure grains. Homogenization at 800°C and subsequent rapid quenching formed a uniform solid solution alpha-(CuNiSn) phase. Direct aging at 350°C from the homogenized Cu-5Ni-10Sn alloy promoted the precipitation of finely distributed gamma' or gamma-(Cu,Ni)_3Sn phase throughout the matrix, resulting in a significant increase in microhardness and tensile strength. Cold working prior to aging was effective in strengthening Cu-5Ni-10Sn alloy, which gave rise to a maximum tensile strength of 1165 MPa. Subsequent aging treatment slightly reduced the tensile strength to 1000-1100 MPa due to annealing effects.

• Keywords: Cu-Ni-Sn;Spray forming;Cold working;Age hardening;Tensile strength;