Development of suitable CuSnZnNi pre-alloyed powder for diamond tools

Based on the composition of CuSn alloy, Zn and Ni elements were added to develop CuSnZnNi pre-alloyed powder, which would overcome the problems of low hardness, weak holding power of diamond and poor universality of CuSn10. CuSnZn alloy was prepared by adding 20% zinc element. Compared with CuSn10 alloy, the temperature difference between solid and liquid phase decreased from 170 ℃ to 34 ℃, and the fluidity of the alloy was significantly improved.The microstructure of CuSn eutectoid phase (α+δ) increased significantly with the addition of Zn element. Meanwhile, α -(Cu, Sn) phase gradually transformed into α -(Cu, Zn) phase in the sintered matrix. XRD analysis showed that δ phase of Cu₆Sn₅, Cu₄₁Sn₁₁, Cu_5.6Sn and γ phase of Cu₅Zn₈ were formed in the alloy. The results show that the grain size of the alloy could be refined and the density of sintered body improved by adding nickel element continuously. At the same time, Ni could strengthen the phase structure and prevent the crack growth. Solid solution of α-(Cu, Ni) and intermetallic compound Ni₃Sn appeared in the alloy. The results show that the pre-alloyed powder could improve the sintering performance of diamond tools, which have excellent adaptability.