【作者】 张敏；

【导师】 陈红梅；

【作者基本信息】 广西大学 ， 材料学， 2015， 硕士

【摘要】 Zr、Cu、Cr、Fe和Sn等是核用锆合金材料的重要合金元素。近几年,Cu元素作为锆合金重要添加元素受到广泛关注,可以有效提高锆合金耐腐蚀性能。研究Cu元素与其他锆合金元素间的相组成关系,将为解释相关锆合金的相变过程、控制锆合金第二相析出、建立面向计算机辅助设计的新型锆合金热力学数据库提供基础数据。本文利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和能谱分析(EDX)等实验方法研究测定了Zr-Cr-Cu. Zr-Fe-Cu两个三元合金体系700℃等温截面相图,并进一步拓展研究了(Zr-1.5Sn)-Fe-Cu伪三元体系700℃部分等温截面相图,获得了以下重要的研究成果：(1) 建立了Zr-Cr-Cu三元系700℃等温截面。证实此截面包含9个三相区、18个两相区及10个单相区。第三组元Cr的加入导致高温CuZr相共析分解温度下降,在700℃时形成稳定的三元相τ。研究确定体系中富锆角和富铜角不存在三元化合物。富锆区合金由ZrCr2、(a-Zr)和CuZr2三相构成。富铜区合金由(Cr)、(Cu)和Cu5Zr相构成。(2) 建立了Zr-Fe-Cu三元系700℃等温截面。证实此截面存在两个三元固溶相Zr(Fe,Cu)和Zr2(Fe,Cu),分别用τ1和钇表示。确定体系中存在七个稳定二元化合物Fe2Zr、FeZr3、CuZr2、Cu10Zr7、Cu8Zr3、Cu51Zr14和Cu5Zr,其中Cu51Zr14对第三组元表现出较大的替代固溶范围,体系中不存在Fe23Zr6相。(3) 建立了(Zr-1.5Sn)-Fe-Cu伪三元系700℃部分等温截面。发现一个新的三元相Zr50Cu30Sn20,其成分比接近5：3：2,用T3表示。此截面存在四个三元相,分别为τ1相、τ2相、θ相和T3相。确定体系中存在τ2+θ+Zr+CuZr2、 τ1+τ2+θ+Fe2Zr、τ1+τ2+θ+CuZr2和τ1+T3+Fe2Zr+Cu8Zr3四个四相区。更多还原

【Abstract】 Zr, Cu, Cr, Fe and Sn are important alloying element of the Zirconium alloys. In recent years, Cu element attracted much attention as an important additional zirconium alloy elements for its effective improvement of corrosion resistance of zirconium alloy. The knowledge for the interaction of Cu and the other alloying elements, would explain phase transition of the Zirconium alloy, and control second-phase paticles precipitation. In this work, the isothermal sections of the Zr-Cr-Cu and Zr-Fe-Cu ternary systems at 700℃ were investigated by using X-ray diffraction, scanning electron microscope and energy dispersive analysis. Moreover, a further research on the isothermal section of the (Zr-1.5Sn)-Fe-Cu pseudo-ternary system at 700℃ in the Zr-rich corner was carried out. Some important results are listed as follow,(1) The isothermal section of the Zr-Cr-Cu ternary system at 700℃ has been established. It is composed of 9 three-phase regions,18 two-phase regions and 10 single-phase regions. The τ phase was observed to occur as a stable ternary phase at 700℃ when Cr was introduced. No ternary compound was observed in the Zr-rich corner and Cu-rich corner. The alloys in Zr-rich corner is consists of ZrCr2, (a-Zr) and CuZr2, while those in the Cu-rich corner is consists of (Cr), (Cu) and(2) The isothermal section of the Zr-Fe-Cu ternary system at 700℃ has been established. Two Zr-Fe-Cu ternary phase, Zr(Fe,Cu) and Zr2(Fe,Cu), named τ1 and τ2, have been found in this section. There have nine binary phase, Fe2Zr, FeZr3, CuZr2, Cu10Zr7, CugZr3, Cu51Zr14 and Cu5Zr, were stable at this temperature. Large amount of Fe was found to solute in Cu51Zr14, the solubility of Fe in Cu51Zr14 is 18.6%. In addition, the oxygen stablilized phase Fe23Zr6 wasn’t observed in Zr-Fe-Cu ternary system.(3) The isothermal section of (Zr-1.5Sn)-Fe-Cu pseudo-ternary system at 700℃ for Zr-rich corner has been established. There are four ternary phases, τ1, τ2,9 and τ3, have been found in this section. The new ternary phase τ3 belong to Zr-Sn-Cu ternary system, with an approximate composition ratio of Zr:Sn:Cu=5: 2:3. Four quaternary-phase regions in Zr-rich corner were evidenced by equilibrated alloys. The obtained isothermal section of (Zr-1.5Sn)-Fe-Cu pseudo-ternary is compatible with the Zr-Fe-Cu and Zr-Sn-Fe ternary systems. Because of the lack of the precise information on Zr-Sn-Cu ternary system, the details of τ3 in Zr-Sn-Cu ternary system are needed further investigation.更多还原