Study of Structural Changes in Cu-Ni-Zn Mixture in Producing of Nickel Silver Alloys by Mechanical Alloying

Production of nickel-silver by mechanical alloying was investigated. Effects of parameters such as milling duration, ball to powder weight ratio, and chemical composition on mechanical alloying process, and alloys color and microstructure were studied. The milled powders were characterized, using XRD and SEM. Results showed that nickel-silvers could be produced by mechanical alloying in a wide range of compositions. Alloyed powder with a bright silvery contrast and less than 15 nm grain size could be obtained by optimization of milling parameters. Zinc content of the powder mixture had a significant effect on the minimum alloying time. Ball to powder ratio up to 25 also reduced minimum alloying time but it had no significant effect above this value.