Zr-Fe-Si体系580℃富Zr端相关系研究

Study on the Phase Relations in Zr-Rich Region of Zr-Fe-Si System at 580℃

采用平衡合金法,通过X射线粉末衍射(XRD),扫描电子显微镜(SEM)及能谱分析(EDS)等手段研究了Zr-Fe-Si体系富Zr端580℃下的相平衡关系,包括5个两相区和2个三相区,两相区为Zr_(2)Si+Zr_(2)Fe、Zr_(2)Fe+ZrFe_(2)、Zr_(2)Fe+Zr_(3)Fe、Zr_(2)Si+Zr_(5)Si_(3)和α-Zr+Zr_(2)Si,三相区为α-Zr+Zr_(2)Fe+Zr_(3)Fe和α-Zr+Zr_(2)Si+Zr_(5)Si_(3)。本工作观察到已有Zr-Fe和Zr-Si相图中在580℃下为不稳定相的Zr_(2)Fe和Zr_(5)Si_(3),第3组元Si的溶入使Zr_(2)Fe稳定温度范围扩大;第3组元Fe溶入Zr_(5)Si_(3)的含量仅1%左右,不太可能使此相稳定温度扩大到如此幅度,Zr_(5)Si_(3)的稳定温度应重新测量和评估。相同晶体结构的Zr_(2)Si和Zr_(2)Fe部分固溶,Fe在Zr_(2)Si中的固溶度达到5.95at%,Si在Zr_(2)Fe中的固溶度达到6.38at%,立方结构ZrFe_(2)能固溶3.11at%Si。

Phase equilibria in the Zr-rich region of Zr-Fe-Si system at 580℃was determined by equilibrated alloy method using X-ray powder diffraction(XRD),scanning electron microscope(SEM)and energy dispersive x-ray analysis(EDS).Five two-phase equilibria Zr_(2)Si+Zr_(2)Fe,Zr_(2)Fe+ZrFe_(2),Zr_(2)Fe+Zr3Fe,Zr_(2)Si+Zr_(5)Si_(3),α-Zr+Zr_(2)Si and two three-phase equilibriaα-Zr+Zr_(2)Fe+Zr3Fe,α-Zr+Zr_(2)Si+Zr_(5)Si_(3) were included.The compounds Zr_(2)Fe and Zr_(5)Si_(3) which were marked as unstable phases at 580℃in the available Zr-Fe and Zr-Si phase diagrams are observed.The dissolution of Si enlarges the stable temperature range of Zr_(2)Fe.The content of Fe dissolved in Zr_(5)Si_(3) is only about 1%,it is unlikely that the phase stabilization temperature range will be greatly expanded and the stable temperature of Zr_(5)Si_(3) can be re-measured and evaluated.It is shown that Zr_(2)Fe and Zr_(2)Si with same crystal structure are partially miscible.Solubility of Fe in Zr_(2)Si is up to 5.95at%and solubility of Si in Zr_(2)Fe is up to 6.38at%.ZrFe_(2)(cubic crystal structure)dissolves 3.11at%of Si.