In situ consolidation of ball milled metals

Abstract

Dry ball milling of face centered cubic metals can lead to a so-called in situ consolidation phenomenon by which relatively large, spherical particles of the milled material evolve. In this study the in situ consolidation of Ag, Al, Ni and Pd has been investigated. In particular the effect of different environments (milling media and atmosphere) on this process had been studied. A possible mechanism of evolution of the spherical particles has been revealed. The presence of a small amount of oxygen slows down the evolution of spherical particles; more oxygen results in a different morphology (flaky particles, instead of spherical ones). The occurrence of in situ consolidation is independent of the crystal structure of the metal concerned. It is concluded that the intrinsic strength of a metal determines the whether or not occurrence of spherical particles during ball milling. © 2016 Elsevier B.V.