Gubicza J, Ribárik G, Bakonyi I, Ungár T
Department of General Physics, Eötvös University, P.O. Box 32, H-1518, Budapest, Hungary.
J Nanosci Nanotechnol. 2001 Sep;1(3):343-8. doi: 10.1166/jnn.2001.039.
A rapidly quenched nanocrystalline Hf11Ni89 alloy was produced by melt-spinning. The x-ray phase analysis shows that the as-quenched ribbon consists mainly of nanocrystalline fcc HfNi5 although a small amount of Ni(Hf) solid solution is also detected. The crystallite size distribution and the dislocation structure of the dominant HfNi5 phase were determined by a recently developed method of diffraction profile analysis. In this procedure, by assuming spherical shape and log-normal size distribution of crystallites, the Fourier coefficients of the measured physical profiles are fitted by the Fourier coefficients of well established ab initio functions of size and strain peak profiles. The anisotropic broadening of peak profiles is accounted for by the dislocation model of the mean square strain in terms of average dislocation contrast factors. It was found that the median and the variance of the crystallite size distribution are 3.3 nm and 0.82, respectively. The dislocation density is 3.7 x 10(16) m-2 and the character of dislocations is nearly pure screw. The results obtained from x-rays were in good agreement with transmission electron microscopy observations.
通过熔体纺丝制备了一种快速淬火的纳米晶Hf11Ni89合金。X射线相分析表明，尽管也检测到少量的Ni(Hf)固溶体，但淬火态薄带主要由纳米晶面心立方HfNi5组成。通过最近开发的衍射轮廓分析方法确定了主要HfNi5相的微晶尺寸分布和位错结构。在此过程中，通过假设微晶为球形且尺寸分布为对数正态分布，将测量的物理轮廓的傅里叶系数与已建立的尺寸和应变峰轮廓的从头算函数的傅里叶系数进行拟合。峰轮廓的各向异性展宽由基于平均位错对比度因子的均方应变位错模型来解释。结果发现，微晶尺寸分布的中位数和方差分别为3.3nm和0.82。位错密度为3.7×10(16) m-2，位错特征几乎为纯螺型。X射线获得的结果与透射电子显微镜观察结果吻合良好。
