Work of formation of grain boundaries upon metal plastic deformation

Abstract

The mechanical treatment of a number of powder metals (Al, Ni, Fe, Cu, Ag, and W) was investigated. It was shown that the work of formation of grain boundaries AS is of the order of several hundreds J/m2. Using iron powder as an example, it was established that AS values are constant at energy doses up to 5–10 kJ/g (the surface area of grain boundaries does not exceed 20 m2/g) and independent on the energy intensity of a device (from 10–1 to 10 W/g). As a rule, the addition of other powder metals (no more than 40 at. %) to iron powder leads to an increase in the AS value.