Some observations on the vibratory blending of metal powders.

Conclusions reached by this investigation include the following: (i) vibratory blending establishes a steady state in which homogenizing processes establish a balance with segregating processes; (ii) the major homogenizing process that is active in vibratory blending exists in the formation of a fluidized zone at the top surface of the bed. Convective and diffusive blending contribute to a lesser degree; (iii) segregation occurs by cluster formation as a result of convective action and also by percolation; (iv) differences in particle size promote segregation by percolation, particularly at size ratios above 2.5; and (v) the segregating tendency becomes less pronounced the broader the size distribution in the size fraction that is used in making the blend. (A)