Synthesis of Sn-Bi-Cu Intermetallic Compound Nanoparticles by Pulsed Wire Discharge of Sn-Bi and Cu Wires

Nanoscale compound powders of Sn-Bi-Cu were successfully synthesized using pulsed wire discharge (PWD). Sn-Bi-Cu powder is used Pb-free soldering materials at low temperature. When the particle size of the Sn-Bi-Cu synthesized as nano-scale has the advantage of lowering the melting point, improving wettability, and stabilizing reaction interface. In PWD, when a high current is passed through high-density metal wires, the wire explodes because of resistance heating, which forms fine particles or metal vapor. We used two wires, Sn-Bi alloy wires and Cu wires, to obtain three-component nanopowders. A high current was applied to the wires between the electrodes in a N-2 atmosphere. We discuss the results based on the K factor, which is E-C/E-V, where E-C and E-V are the charging energy of the capacitor and the vaporization energy of the wire, respectively. Nanoparticles with three components, Sn-Bi-Cu, were synthesized under N-2 atmosphere at voltages of 4/6 kV. According to the particle-size distributions, the mean particle diameter of the prepared Sn-Bi and Cu nanopowders was 14.56-40.36 nm for each condition. In this study, We successfully three-component nanopowders synthesized and subjected two wires to extreme energies by the PWD method to form a nanopowder by overcoming its limited solid solubility.