锆合金中第二相的研究

Study of Second Phase Particles in Zirconium Alloys

摘要:

将几种Nb、Fe含量不同的锆合金样品在1050 ℃保温0.5 h后水冷，在560 ℃回火10 h，用带能谱分析(EDS)的透射电子显微镜研究它们的第二相粒子。结果显示：随着合金样品中Nb元素含量的提高及Nb/Fe比的增加，第二相从Zircaly-4合金中密排六方结构的Zr(Fe,Cr)2向密排六方的Zr(Nb,Fe,Cr)2转变，同时Zr(Nb,Fe,Cr)2中的Nb/Fe比也在提高。当样品中Nb元素含量和Nb/Fe比提高到一定程度，除了生成密排六方结构的Zr(Nb,Fe,Cr)2，同时出现了体心立方结构的βNb

Abstract:

Zirconium-based alloys with different Nb and Fe addition ratios were treated by β-quenching at 1050 oC for 0.5 h and the followed annealing at 560 oC for 10 h; then their microstructure and second phase particles (SPPs) were examined by high-resolution transmission electron microscopy (HR-TEM) equipped with an energy dispersive X-ray spectroscopy (EDS). Results show that with the increasing of Nb addition and the Nb/Fe ratios, SPPs Zr(Fe,Cr)2 with a hexagonal close packed (HCP) structure in Zircaly-4 transform to SPPs Zr(Nb,Fe,Cr)2 with a hexagonal close packed structure; meanwhile the Nb/Fe ratio of Zr(Nb,Fe,Cr)2 is increased too. SPPs βNb with a body center cubic structure could be observed besides HCP-Zr(Nb,Fe,Cr)2 precipitates when Nb contents and Nb/Fe ratios are high enough