利用控制凝固过程的定向凝固技术生长出了直径０．８长１０ｍｍ的Ａｌ－Ｃｕ－Ｃｏ－Ｇｅ十边形准晶单晶．在准晶生长过程中，所有准晶单晶形成了单一取向的择优生长结构，其棱柱的中心轴为十次旋转对称轴．在温度梯度为９５℃／ｃｍ的条件下，随着定向凝固速度的增大，生长界面出现的成分过冷越来越大，从而导致生长界面的扰动也逐渐加剧并使成分偏析，界面形态由平面向胞状和树枝状转化，出现大量非准晶相，最后无法生长出所需要的高质量准晶单晶．
The large single decagonal quasicrystals of 0.8 mm in diameter and 10 mm in length in Al-Cu-Co-Ge alloy have been obtained by controlled unidirectional solidification.In the process of growth, all of the single quasicrystals grew preferentially along uni-orientation of solidification.The centre axis of quasicrystalline prisms is the tenfold rotational symmetry axis. Under the condition of temperature gradient about 95℃/ cm,the segregation will be occurred and the growing interface will be changed from planar structure into cellular and/ or dendritic one with increasing directional solidification rate.and a large number of crystalline phases will be produced. Thus,it seems to be no means of growing required single quasicrystals of high quality.Correspondent:CHEN Lifan, Institute of physics,Chinese Academy of Science, Beijing 100080
参考文献
| [1] | |
| [2] | |
| [3] | |
| [4] | |
| [5] | |
| [6] | |
| [7] | DubostB,LangJM,TanakaM,SainfortP,AudierM．Nature,1986 |
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