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%.

組織和性能檢測(cè)表明:在連續(xù)ECAP變形一道次后,在晶粒內(nèi)部形成了直徑為650~900 nm且內(nèi)部基本無位錯(cuò)的亞晶,但部分大晶粒內(nèi)部仍存在高密度的位錯(cuò)網(wǎng),材料硬度提高了87%;經(jīng)過4道次連續(xù)ECAP變形后,亞晶并未進(jìn)一步細(xì)化,但亞晶界趨于平直、清晰,且亞晶內(nèi)部基本未見位錯(cuò)組織,材料硬度提高也不顯著;與傳統(tǒng)ECAP相比,連續(xù)ECAP工藝由于具有較高的變形區(qū)溫度,促進(jìn)了晶內(nèi)位錯(cuò)的反應(yīng)即動(dòng)態(tài)回復(fù)過程,較早形成了平直清晰的亞晶結(jié)構(gòu),同時(shí)伴隨每道次變形過程的動(dòng)態(tài)回復(fù)也降低了最后晶格中累積的能量,使變形兩道次后的組織和性能變化不顯著。

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

結(jié)果表明:在變形帶中,鐵素體沿平行于剪切應(yīng)力方向形成條帶狀亞晶, {110}晶面為變形條帶狀亞晶的滑移面,條帶狀亞晶內(nèi)存在高密度位錯(cuò);經(jīng)退火處理后,條帶狀亞晶內(nèi)的位錯(cuò)束集成與條帶狀亞晶界垂直的位錯(cuò)胞壁,形成類方形位錯(cuò)胞結(jié)構(gòu);進(jìn)一步經(jīng)位錯(cuò)胞壁的擴(kuò)散遷移,形成各胞壁之間呈120°夾角的亞晶結(jié)構(gòu)。

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

利用 ＴＥＭ分析了合金在不同壓縮條件下的組織形貌特征，采用ＥＢＳＰ分析了晶粒間的取向差，研究了其動(dòng)態(tài)再結(jié)晶行為通過回歸分析建立了７００５合金熱變形條件與變形亞晶尺寸間關(guān)系的半經(jīng)驗(yàn)?zāi)Ｐ汀?/p>

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

在較低的應(yīng)變量下纖維保持著與鑄態(tài)樹枝晶相同的bcc單晶結(jié)構(gòu),在較高的應(yīng)變量下,單根Cr纖維被分隔為一些由亞晶界組成的亞結(jié)構(gòu),相鄰亞晶的偏差角在5~30°之間。

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.

雙晶X射線衍射(DCXRD)與透射電子顯微鏡(TEM)觀察發(fā)現(xiàn),單緩沖層上生長(zhǎng)的樣品晶體質(zhì)量較差,內(nèi)部含有位錯(cuò)、反疇區(qū)和亞晶粒等缺陷,而雙緩沖層上生長(zhǎng)的GaN只含有較低密度的位錯(cuò),說明雙緩沖層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合金管材陽極氧化后顏色不均勻,通過對(duì)管材組織特征的觀察和模擬試驗(yàn),確定管材中某些部位存在大量的亞晶粒,它是造成顏色發(fā)黑的根本原因。

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

參照美國一鋁業(yè)公司熱軋工藝規(guī)程，在Ｇｌｅｅｂｌｅ－１５００熱模擬機(jī)上，對(duì)工業(yè)純鋁多道次熱軋過程進(jìn)行了實(shí)驗(yàn)?zāi)M，通過對(duì)變形后試樣組織的金相與ＴＥＭ觀察及顯微硬度測(cè)量，發(fā)現(xiàn)亞晶粒隨著道次增加逐漸形成完善，其尺寸逐漸變??；再結(jié)晶不僅取決于軋制溫度，而且還與變形不均勻帶，累積變形量及道次間停留時(shí)間有關(guān)；在試樣厚度較大的某些道次，發(fā)生再結(jié)晶的位置交替地由高向兩側(cè)轉(zhuǎn)向中心部位。