Oberdorfer Bernd, Lorenzoni Bernd, Unger Katrin, Sprengel Wolfgang, Zehetbauer Michael, Pippan Reinhard, Würschum Roland
Institut für Materialphysik, Technische Universität Graz, Petersgasse 16, A-8010 Graz, Austria.
Scr Mater. 2010 Aug;63(4):452-455. doi: 10.1016/j.scriptamat.2010.05.007.
A maximum excess volume ΔV/V ≈ 1.9 × 10(-3) in ultrafine-grained Fe prepared by high-pressure torsion is determined by measurements of the irreversible length change upon annealing employing a high-resolution differential dilatometer. Since dislocations and equilibrium-type grain boundaries cannot fully account for the observed released excess volume, the present study yields evidence for a high concentration of free volume-type defects inherent to nanophase materials, which is considered to be the main source of their particular properties, such as strongly enhanced diffusivities.
通过使用高分辨率差动膨胀仪测量高压扭转制备的超细晶粒铁在退火时的不可逆长度变化，确定了其最大过剩体积ΔV/V≈1.9×10⁻³ 。由于位错和平衡型晶界无法完全解释观察到的释放过剩体积，本研究为纳米相材料固有的高浓度自由体积型缺陷提供了证据，这些缺陷被认为是其特殊性能（如显著增强的扩散率）的主要来源。
