metacrystalline

After one ECAP deformation pass,profuse subgrains with the size of 650900nm are formed,few dislocations can be found inside the subgrains,but high density dislocation networks still are observed in some grains,the hardness of material increases 87%.

组织和性能检测表明:在连续ECAP变形一道次后,在晶粒内部形成了直径为650~900 nm且内部基本无位错的亚晶,但部分大晶粒内部仍存在高密度的位错网,材料硬度提高了87%;经过4道次连续ECAP变形后,亚晶并未进一步细化,但亚晶界趋于平直、清晰,且亚晶内部基本未见位错组织,材料硬度提高也不显著;与传统ECAP相比,连续ECAP工艺由于具有较高的变形区温度,促进了晶内位错的反应即动态回复过程,较早形成了平直清晰的亚晶结构,同时伴随每道次变形过程的动态回复也降低了最后晶格中累积的能量,使变形两道次后的组织和性能变化不显著。

The results show that the subgrain structures of the ferrite-strip along the drawing direction are formed in the deformation bands of steel.

结果表明:在变形带中,铁素体沿平行于剪切应力方向形成条带状亚晶, {110}晶面为变形条带状亚晶的滑移面,条带状亚晶内存在高密度位错;经退火处理后,条带状亚晶内的位错束集成与条带状亚晶界垂直的位错胞壁,形成类方形位错胞结构;进一步经位错胞壁的扩散迁移,形成各胞壁之间呈120°夹角的亚晶结构。

Semi-empirical relations between subgrain sizes and deformation variables were construct.

利用 ＴＥＭ分析了合金在不同压缩条件下的组织形貌特征，采用ＥＢＳＰ分析了晶粒间的取向差，研究了其动态再结晶行为通过回归分析建立了７００５合金热变形条件与变形亚晶尺寸间关系的半经验模型。

At higher drawing strains,a single fiber was divided into sub-grains.

在较低的应变量下纤维保持着与铸态树枝晶相同的bcc单晶结构,在较高的应变量下,单根Cr纤维被分隔为一些由亚晶界组成的亚结构,相邻亚晶的偏差角在5~30°之间。

GaN epilayer grown on single buffer layer has poor quality which were investigated by double-crystal X-ray diffraction (DCXRD) and transmission electron microscope (TEM), it can be seen that there are dislocations, inversion domains and sub-grains, while just low density dislocations can be seen in GaN epilayer.

双晶X射线衍射(DCXRD)与透射电子显微镜(TEM)观察发现,单缓冲层上生长的样品晶体质量较差,内部含有位错、反畴区和亚晶粒等缺陷,而双缓冲层上生长的GaN只含有较低密度的位错,说明双缓冲层有效地降低了缺陷密度。

It is sure that there are a lot of subgrains in some sections of the tube, which is the basic cause of bringing about that the tube colour turns into the black, through the investigation and the simulation test to the macrostructure characteristics of the tube, the fonnation mechanism about the subgrains and the methods to eliminate them are explained.

7A04CS合金管材阳极氧化后颜色不均匀,通过对管材组织特征的观察和模拟试验,确定管材中某些部位存在大量的亚晶粒,它是造成颜色发黑的根本原因。

It was shown that the subgrains are well formed and the size decrease withincreasing of rolling pass.

参照美国一铝业公司热轧工艺规程，在Ｇｌｅｅｂｌｅ－１５００热模拟机上，对工业纯铝多道次热轧过程进行了实验模拟，通过对变形后试样组织的金相与ＴＥＭ观察及显微硬度测量，发现亚晶粒随着道次增加逐渐形成完善，其尺寸逐渐变小；再结晶不仅取决于轧制温度，而且还与变形不均匀带，累积变形量及道次间停留时间有关；在试样厚度较大的某些道次，发生再结晶的位置交替地由高向两侧转向中心部位。