Long-period stacking ordered structures in Mg-3Cu-1Mn-2Zn-1Y damping alloy  

Mg-3Cu-1Mn-2Zn-1Y阻尼合金中的长周期结构(英文)

作　　者：黄雪飞[1] 张文征[1] 王敬丰[2] 魏文文[2] 

机构地区：[1]清华大学材料科学与工程系,先进材料教育部重点实验室,北京100084 [2]重庆大学材料科学与工程学院,重庆400044

出　　处：《Transactions of Nonferrous Metals Society of China》2012年第8期1947-1953,共7页中国有色金属学报（英文版）

基　　金：Project (2009CB623704) supported by the National Basic Research Program of China;Project (50971076) supported by the National Natural Science Foundation of China

摘　　要：14H, 18R and 24R long-period stacking ordered （LPSO） structures were observed in the as-cast Mg-3Cu-1Mn-2Zn-1Y damping alloy using transmission electron microscopy （TEM）. These LPSO structures contained Mg, Y, Cu and Zn and thus they were quaternary phases. Sharp diffraction pattern of the 24R structure was obtained and the angle between and g10024R was measured to be 5.03°. During high resolution TEM observations, lattice fringes with two characteristic spacings were observed within the 24R structure. Based on the experimental results, 6H, 7H and three 8H are suggested as the building blocks of 18R, 14H and 24R structures, respectively. The 24R unit cell can be interpreted as the stacking of 8H building blocks in the same shear direction with a shear angle of about 5.03°. The imperfect 24R structures are in order or disorder arrangements of principal 8H and minor 6H blocks. This double-block structure model is also applicable to other reported defects in LPSO structures.通过透射电子显微镜对铸态Mg-3Cu-1Mn-2Zn-1Y阻尼合金进行表征,观察到14H、18R和24R三种类型的长周期结构。这些长周期结构含有Mg、Y、Zn和Cu的四元相。获得了24R结构的明锐衍射斑点,并测得衍射斑中g1100与g10024R的夹角为5.03°。高分辨晶格条纹显示,24R结构中经常包含两种类型的特征条纹间距。基于实验结果提出,将6H、7H和8H分别作为18R、14H和24R长周期结构的结构单元。24R结构的单胞可以认为是由三个8H单元沿相同的方向切变5.03°堆垛而成的,具有缺陷的24R结构主要是由8H单元和少量的6H单元通过有序或者无序的方式堆垛而成的。这种双单元结构模型也可以解释之前观察到的长周期结构中的缺陷。

关 键 词：magnesium alloys long-period stacking ordered structure TEM building block 

分 类 号：TG146.22[一般工业技术—材料科学与工程]