Fabrication of hollow nickel micro-spheres with high degree of hollowness by silicon powder-mixed spark erosion

For the purpose of developing a simple, fast and low cost method to fabricate the hollow nickel micro-spheres, the hollow nickel micro-spheres with high degree of hollowness were fabricated by silicon powder-mixed spark erosion (SPMSE) in the present paper. Morphologies and loose packed densities of hollow nickel micro-spheres fabricated by the SPMSE and conventional spark erosion (CSE) respectively were studied. The results showed that the hollow nickel micro-spheres fabricated by the SPMSE are bigger and exhibit higher degree of hollowness as compared to the CSE. It is expected that the powder-mixed spark erosion can fabricate hollow nickel micro-spheres with satisfactory particle size and hollowness through adjusting the particle size of silicon powders and machining parameters, even selecting other kinds of semi-conductive or conductive powders. In addition, the powder-mixed spark erosion can also fabricate other kinds of hollow metallic micro-spheres.