| In this study, the influence of additional amounts of Ni and Sn on mechanical, electrical properties, and microstructure of Cu-base alloys was studied and then was investigated on the fitness of these alloys to a lead frame material in electronics. The grain of Cu-Ni-Sn alloys was finer than that of Cu-Sn alloy, which resulted in improvement of the strength and hardness. The effect of Ni addition on the strength was clear below lwt% but insensible above it. Compared with Cu-4wt%Sn alloy, the strength level of alloys added 0.5-lwt%Ni and 1-1.5wt%Sn showed similar to that of Cu-4wt%Sn alloy, but electrical conductivity showed about twice as high as that of Cu-4wt%Sn alloy. Meanwhile, Cu-base alloys containing 0.5-lwt%Ni and 1-1.5wt%Sn showed the good work hardenability with a high value above Hv 150 by 50% cold working and the good thermal resistivity with the tensile strength of 35㎏/㎟, even when they were annealed for 30min. at 600℃. From the above results, it seemed that Cu-0.5∼1wt%Ni-1∼1.5wt%Sn alloys could be applicable to a lead frame material. |
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