Effects of Cold Rolling Deformation on Hardness and Conductivity of Cu-Ni-Si Alloy for Lead Frame

Cold rolling experiments with different deformations were carried out for solid solution state Cu-4.0Ni-0.5Si alloy. The effects of cold rolling deformations on the hardness, electrical conductivity and microstructure of cold rolled and aged Cu-Ni-Si alloy were studied by means of Vickers hardness tester, eddy current conductance tester and SEM.The results show that the hardness of Cu-4.0Ni-0.5Si alloy increases obviously and the conductivity decreases after cold rolling.The aging treatment at 450 ℃for cold rolled alloys with different deformation amounts is carried out, the larger the deformation amount of cold rolled alloy, the more complete the precipitation of alloying elements during the aging process of Cu-4.0Ni-0.5Si alloy, the higher the conductivity of the alloy, and the shorter the aging time for alloy hardness to reach the peak.The conductivity of Cu-4.0Ni-0.5Si alloy with 80%cold rolling+450 ℃×6 h aging is the highest, which is 62.5%IACS.