Effect of preparation conditions on the short-range order in Zr-based bulk glass-forming alloys
Effect of preparation conditions on the short-range order in Zr-based bulk glass-forming alloys
复制标题
制备条件对Zr基大块非晶合金短程有序的影响
DOI：
10.1016/s0921-5093(02)00379-9
复制
发表时间：
2003
期刊：
影响因子：
6.4
通讯作者：
J. Eckert
中科院分区：
文献类型：
--
作者：
L. Damonte;L. Mendoza;S. Deledda;J. Eckert
采用扰动角关联技术（PAC）研究了Zr-Cu-Al-Ni非晶合金在不同冷却速率下的熔体淬火和机械合金化固相反应中的短程有序。所有的样品也通过X射线衍射和差示扫描量热法进行了表征。对于所有制备的无定形样品，PAC光谱很好地描述了一个Czjzek分布揭示了短程有序对应于一个密集的随机堆积的离子。观察到的电场梯度似乎是独立的制备方法，当与以前的测量相比，Zr含量。这些趋势进行了讨论，在比较中观察到的二元非晶合金的类似行为。高于玻璃化转变温度但低于结晶步骤退火的样品显示出两个宽的频率分布，其被分配给亚稳Ti 2Ni型相。
The short-range order in as-prepared and annealed Zr–Cu–Al–Ni glassy alloys, obtained by quenching from the melt at different cooling rates as well as by solid state reaction via mechanical alloying, was investigated by perturbed angular correlations technique (PAC). All the samples were also characterised by X-ray diffraction and differential scanning calorimetry. For all the as-prepared amorphous samples, the PAC spectra are well described by a Czjzek distribution revealing that the short-range order corresponds to that of a dense random packing of ions. The observed electric field gradient seems to be independent of the preparation method and, when compared with previous measurements, of the Zr content. These trends are discussed in comparison with the similar behaviour observed in binary amorphous alloys. Samples annealed above the glass transition temperature but below the crystallisation step showed two broad distributions of frequencies, which were assigned, to a metastable Ti2Ni-type phase.