Formation of quasicrystals in bulk glass forming Zr–Cu–Ni–Al alloys
Formation of quasicrystals in bulk glass forming Zr–Cu–Ni–Al alloys
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DOI：
10.1063/1.117364
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发表时间：
1996-07
影响因子：
4
通讯作者：
U. Köster;J. Meinhardt;S. Roos;H. Liebertz
中科院分区：
文献类型：
--
作者：
U. Köster;J. Meinhardt;S. Roos;H. Liebertz
Zr65Cu17.5Ni10Al7.5和Zr69.5Cu12Ni11Al7.5是目前已知的最好的非晶形成合金。熔融纺带的玻璃化转变温度分别为372℃和360℃。透射电镜和x射线分析表明，在玻璃化转变温度以上退火的样品形成了含有少量晶相的准晶微观结构。亚稳二十面体相为原始相，准晶格常数a=0.253 nm；经EDX测定其成分接近Zr69.5Cu12Ni11Al7.5。在这两种玻璃中，准晶的生长都是随时间变化的（r∝t1/2），因此表明是扩散控制转变。
Zr65Cu17.5Ni10Al7.5 as well as Zr69.5Cu12Ni11Al7.5 belong to the best glass forming alloys known. Glass transition temperatures of melt‐spun ribbons are 372 and 360 °C, respectively. TEM and x‐ray analysis of samples annealed above the glass transition temperature exhibit the formation of quasicrystalline microstructures with small amounts of crystalline phases. The metastable icosahedral phase is primitive with a quasilattice constant a=0.253 nm; its composition as determined by EDX is close to Zr69.5Cu12Ni11Al7.5. In both glasses, growth of the quasicrystals has been observed to be time‐dependent (r∝t1/2), thus indicating a diffusion controlled transformation.