A method and apparatus for affecting the properties of a material include vibrating the material during its formation (i.e., "surface sifting"). The method involves the steps of providing a material formation device and applying a plurality of vibrations to the material during formation, which vibrations comprise oscillations having dissimilar, non-harmonic frequencies and at least two different directions. The apparatus includes a plurality of vibration sources that impart vibrations to the material.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with Government support under Contract DE-AC0576RL01830 awarded by the U.S. Department of Energy. The Government has certain rights in the invention.