THERMAL-STABILITY OF SUBMICRON GRAINED COPPER AND NICKEL

The features of structure and thermal stability of submicron grained c opper and nickel processed by severe plastic deformation are considere d. The results of studies by various techniques: transmission electron microscopy, X-ray diffraction, differential scanning calorimetry, ele ctrical resistance and microhardness are presented. The investigations have shown that thermal stability of submicron grained materials is d etermined not only by a mean grain size but also by the density and di stribution of the grain boundary dislocations. The relaxation of the g rain boundary dislocations precedes the grain growth starting at 175 d egrees C and influences on thermal stability. (C) 1997 Elsevier Scienc e S.A.