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研究了 8090 合金超塑性变形中的位错行为。透射电镜观察表明晶内位错产生于三角晶界,晶界台阶和粒子处。在变形初期,晶内位错滑移相当活跃;在变形中期,晶内位错发生回复形成亚晶界;至变形末期,虽然位错回复过程没有停止,但位错滑移协调机制变得更重要了,研究指出,位错滑移是变形初期的主要变形机制。动态回复和位错滑移都是晶界滑动的协调机制。而且,螺型位错与空位交互作用形成不能滑动的卷位错提高了晶内畸变能,促进了动态再结晶。
The dislocation behavior of 8090 alloy in superplastic deformation was studied. Transmission electron microscopy showed that intragranular dislocations were generated at the triangular grain boundaries, grain boundary steps and particles. In the early stage of deformation, the intracrystalline dislocation slip is very active. During the middle stage of deformation, the intragranular dislocation reverts to form a subgrain boundary. At the end of deformation, although the dislocation recovery process does not stop, the dislocation slip coordination mechanism becomes more Important, the study pointed out that dislocation slip deformation is the main deformation mechanism. Dynamic response and dislocation slip are the coordination mechanisms of grain boundary sliding. Moreover, the formation of a non-slip volume displacement by the interaction of screw dislocations and vacancies increases the intragranular distortion energy and promotes dynamic recrystallization.