The beta to alpha phase transformation in zircaloy-4
The beta to alpha phase transformation in zircaloy-4
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DOI：
10.1016/0022-3115(70)90216-3
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发表时间：
1970-06
影响因子：
3.1
通讯作者：
R. Holt
中科院分区：
文献类型：
--
作者：
R. Holt
在名义上相似的 Zircloy-4 中观察到两种不同的魏德曼组织形态。这种结构上的差异与 β 相到 α 相变的动力学差异是一致的。对现有平衡数据的讨论以及平衡转变的实验研究表明，这种动力学差异是成核机制差异而不是生长机制差异的结果。这与不溶于β相的第二相颗粒的丰度和尺寸有关，它们优先于β晶界充当成核位点。经典成核理论用于解释这种偏好。有证据表明，一些颗粒是 NaCl 立方结构，晶格参数为 5.25 Å，相当于磷化锆 (ZrP)。还表明合适的成核位点的存在可能取决于碳、氧和氮以及磷含量
Two different Widmanstätten morphologies have been observed in nominally similar Zircaloy-4. This difference in structure is shown to be coincident with a difference in the kinetics of the beta to alpha phase transformation. Discussion of existing equilibrium data, and experimental investigation of the equilibrium transformation show that this difference in kinetics is a result of a difference in nucleation mechanism rather than a difference in growth mechanism. This is related to the abundance and size of second phase particles, insoluble in the beta phase, which act as nucleation sites in preference to the beta grain boundaries. Classical nucleation theory is used to explain this preference. There is evidence that some of the particles are NaCl cubic structure with a lattice parameter of 5.25 Å which corresponds to zirconium phosphide (ZrP). It is also suggested that the presence of suitable nucleation sites may depend on the carbon oxygen and nitrogen, as well as phosphorous contents