Mechanism of Continuous Recrystallization under Superplasticity

“研究人员稳步进入了下面的两个头。”（ 1 ） Continuous Recrystallization in a Superplastic Aluminum AlloyThe misorientations of subgrain boundaries evolved in the pancaked grains increase accompanied by a randomization of the initial texture， followed by a new grain development with high angle boundaries （HABs） at high strains。在预冷滚动减少中增加的结果在流动压力中减少和在总长度中快速增加。谷物边界滑动（GBS）通常只需要在分层的HABs平行进入张力轴之后才能找到位置。有了进一步的约束， GBS可以在HABs附近提供亚粒的旋转，从而导致在Mhe亚粒不对称中增加。它包含了一种由冷滚动引入的非递归和开裂的谷物结构，它不仅是超可塑性的一个重要的先验，而且也是新精细谷物的动态演变。（2）新谷物的动态演变 ... More during Hot Deformation of Magnesium Alloy AZ31The flow curve shows a rapid hardening and a stress peak at relatively low strain （_p =0）。12），跟随一条直线软化，然后在一条直线上稳定的状态流动。精细的谷物在原始的谷物边界上进化，并在ε_p周围快速开发了精细的谷物软化，最终导致了一个粗略的、完整的均衡精细的演变。在另一方，金姆乐队演变成谷物边界，而且经常出现在谷物中间人甚至在%左右。Kink波段边界的不对称性增加了在高应变期间快速软化和接近43 °左右的饱和值。该地区的平均大小被Kink乐队分割的几乎和新谷物在高应变中演变的一样，在变形期间发生了可怕的变化。因为它被包括在一起，所以新的谷物进化可以由一种改良诱导的连续反应控制，i.e.连续动态还原（DRX），还有新谷物进化过程的许多特征及其与流动行为的关系在传统上非常相似，i.e.不连续， DRX。Less（低）

The research falls roughly into the following two heads.( 1 ) Continuous Recrystallization in a Superplastic Aluminum AlloyThe misorientations of subgrain boundaries evolved in the pancaked grains increase accompanied by a randomization of the initial texture, followed by a new grain development with high angle boundaries (HABs) at high strains. Increasing in the pre cold-rolled reduction results in a decrease in the flow stress and a rapid increase in total elongation. Grain boundary sliding (GBS) frequently takes place just after yielding even in the layered HABs parallel to the tensile axis. With further straining, GBS can bring about the rotation of subgrains near the HABs, leading to increase inMhe subgrain misorientation. It is concluded that nonrecrystallized and pancaked grain structure introduced by cold rolling is an important prerequisite not only for the appearance of superplasticity, but also for the dynamic evolution of new fine grains.(2) Dynamic Evolution of New Grains … More during Hot Deformation of Magnesium Alloy AZ31The flow curve shows a rapid hardening and a stress peak at relatively low strain (ε_p=0. 12), followed by a strain softening and then a steady state flow in high strain. Fine grains are evolved at original grain boundaries corrugated at around ε_p and developed rapidly during strain softening, finally leading to a roughly full evolution of equiaxial fine grains. On the other hand, kink bands are evolved at grain boundaries corrugated and also frequently in grain interiors even at around %. The misorientation of the boundaries of kink band increases rapidly during strain softening and approach a saturation value of around 43゜ in high strain. The average size of the regions fragmented by kink band is almost the same as that of new grains evolved in high strain, which scarcely changes during deformation. It is concluded therefore that new grain evolution can be controlled by a deformation-induced continuous reaction, i.e. continuous dynamic recrystallization (DRX), although many characteristics of new grain evolution process and its relation to flow behaviors are apparently similar to those in conventional, i.e. discontinuous, DRX. Less