Low-nickel-zinc cupronickel alloy and preparation method thereof

The invention discloses a low-nickel-zinc cupronickel alloy which comprises the following components in percentage by mass: 47.0 to 55.0 percent of Cu, 1.5 to 3.0 percent of Pb, 5.5 to 7.5 percent of Ni, 1.5 to 4.0 percent of Mn, 0.0001 to 0.5 percent of X and the balance of Zn and inevitable impurities, and X is at least one element selected from Fe, Sn and Si. According to the low-nickel-zinc cupronickel alloy, Mn and Pb elements are added into the low-nickel-zinc cupronickel alloy, it is guaranteed that in a microstructure on the cross section of the alloy, the area ratio of alpha phases is 67%-93%, the area ratio of beta phases is 5%-30%, the average area of Pb particles does not exceed 20 mu m < 2 >, the ratio of the number of the Pb particles with the area smaller than 5 mu m < 2 > to the total number of the Pb particles is larger than or equal to 30%, and finally the low-nickel-zinc cupronickel alloy with the excellent cutting performance and the good cutting performance is obtained. The zinc-copper-ni