Formation mechanism of self-organized nanostructured -metallic glass composite

(1)在快速冷却的Cu-(Zr或Hf)-Ti合金中发现了纳米结构-金属玻璃复合材料的形成。(2)纳米晶颗粒直径为5~10 nm，均匀地分散在玻璃基质中。(3)纳米晶颗粒具有亚稳的立方结构，具有富铜成分，这为我们提供了过冷液态下稳定的富铜团簇的形成机制。(4)两种合金体系中的一次转变过程都得到了明确的解释。在此基础上形成了另一个亚稳的CuZr相，使得该合金中的纳米晶立方相保持在淬火状态。而在Cu-Hf-Ti合金中，玻璃相和亚稳态立方相转变为Cu8Hf3相。(5)纳米结构-金属玻璃复合材料具有较高的机械强度，且在初晶化阶段有所改善。(6)研究了纳米二十面体准晶弥散分布的非晶合金的断裂机制。(6)纳米二十面体准晶存在于非晶合金的初始阶段，二十面体团簇在过冷液相中具有较高的稳定性。在这些研究中，我们可以得出结论，利用稳定的除尘器和/或局部结构来控制金属玻璃的纳米结构对提高材料的力学性能是非常有效的，对于研究材料中的形成机制和转变过程等基本性能也是非常重要的。

(1)The formation pf nanostructured-metallic glass composite has been found in the rapidly quendied Cu-(Zr or Hf)-Ti alloys.(2)The nanocrystalline particles have a fine grain size of 5 to 10 nm in diameter and are dispersed homogeneously in the glassy matrix.(3)The nanocrystalline particles have a metastable cubic structure with Cu-rich composition, which are brought us the formation mechanism of the stable Cu-rich clusters in the supercooled liquid state.(4)The primary transformation process is clarified in both the alloy systems, where another metastable CuZr phase is formed remaining the nanocrystalline cubic phase in the as-quenched state in the Cu-Zr-Ti alloy. However, the glassy and metastable cubic phases are transformed into the Cu8Hf3 phase in the Cu-Hf-Ti alloy.(5)The high mechanical strength is exhibited in the nanostructured-metallic glass composite in the Cu-Zr-Ti alloy and it is improved in the primary crystallized state. It is due to the formation of two different nanocrystalline phases.(6)Nano icosahedral quasicrystalline phase formation is found in the primary stage in the Zr65Al7.5Cu27.5 metallic glass, where the icosahedral cluster has a high stability in the supercooled liquid state.(7)The fracture mechanism of the nano icosahedral quasicrystal dispersed Zr-Pt binary amorphous alloy is investigated. We have found that the fracture takes place in the glassy region among the dispersed icosahedral particles.(8)In these studies, we can conclude that the nanoscale structure control based on the metallic glasses using the stable duster and/or local structure is very effective on the improvement of mechanical properties as well as is very important on the investigation of fundamental properties such as the formation mechanism and transformation process in the materials.