Effect of Al Addition on Microstructure and Properties of Cu-5.6Ni-2.5Mn-2Sn Alloy

Through component designing, Cu-5.6Ni-2.5Mn-2Sn alloy with different Al contents (0wt.%, 0.93wt.%, 2.43wt.%) was prepared. In order to research the influence of Al content on microstructure and properties of Cu-5.6Ni-2.5Mn-2Sn alloy, cold deformation and heat treatments were carried out. The results show that there were developed dendrites and segregation of Sn in the cast microstructure of three alloys. After the best aging treatment, the maximum value of hardness hit 236 HV when Al content of the alloy was 2.43wt.%, and the highest conductivity which reached 15.3%IACS when Al content of the alloy was 0wt.%. The hardnesses of three alloys raised with increasing cold deformation degree. The alloy that contented 2.43wt.% Al and with 50% cold deformation degree exhibited the best performance with hardness of 260 HV and conductivity of 10.7%IACS. And severe cracking didn′t occur during hot rolling, therefore it can replace Cu-9Ni-6Sn alloy.