ANELASTIC AND STRUCTURAL BEHAVIOR OF BALL-MILLED NANOSTRUCTURED IRON

Mechanical spectroscopy and XRD analysis were employed to study the an elastic behaviour and structural evolution of nanostructured iron prep ared by mechanical attrition under different conditions. The results s how that the thermally induced structural relaxation, without extensiv e grain growth, leads to strong reductions of the microstrain, dynamic modulus recovery and significant modifications of the anelastic relax ation spectra. These results are compared with those obtained by other structure sensitive techniques. The role of the interfaces and of the ir structural evolution in determining the observed behaviour of diffe rent physical properties is discussed. (C) 1998 Acta Metallurgica Inc.