Formation mechanism of self-organized nanostructured -metallic glass composite

(1)快速淬火Cu-(Zr或Hf)- ti合金中形成了纳米结构的金属玻璃复合材料。(2)纳米晶颗粒粒径为5 ~ 10 nm，均匀分布在玻璃基体中。(3)纳米晶颗粒具有亚稳立方结构，富cu组成，为我们揭示了过冷液态下稳定富cu团簇的形成机理。(4)在Cu-Zr-Ti合金体系中，Cu-Zr-Ti合金的初转变过程得到明确，在Cu-Zr-Ti合金中，除了处于淬火状态的纳米晶立方相外，还形成了另一个亚稳CuZr相。在Cu-Hf-Ti合金中，玻璃相和亚稳立方相转变为Cu8Hf3相。(5) Cu-Zr-Ti合金的纳米结构-金属玻璃复合材料具有较高的机械强度，并在初晶状态下得到提高。这是由于形成了两种不同的纳米晶相。(6) Zr65Al7.5Cu27.5金属玻璃初生阶段形成纳米二十面体准晶相，二十面体团簇在过冷液相中具有较高的稳定性。(7)研究了纳米二十面体准晶分散Zr-Pt二元非晶合金的断裂机理。我们发现断裂发生在分散的二十面体颗粒的玻璃区。(8)在这些研究中，我们可以得出结论，基于金属玻璃的纳米级结构控制使用稳定的粉尘和/或局部结构对力学性能的改善非常有效，并且对材料的形成机制和转变过程等基本性能的研究非常重要。

(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.