Zr-Al-V三元系800℃等温截面实验测定

发布时间：2018-06-04 01:13

  本文选题：Zr-Al-V三元系 + 相图　； 参考：《湘潭大学》2017年硕士论文

【摘要】：开发耐热铝材料是铝合金研究的一个重要方向,而其中钪(Sc)元素作为铝合金添加剂最为有效,仅微量添加,即可使铝合金有极高的强化效应、抗腐蚀性能、优异的焊接性能和耐热性能。但钪的价格昂贵,导致钪铝合金应用范围极小,限于体育和军事。由于锆(Zr)在铝合金中能够形成适合的强化相,工作温度下在Al基体中的固溶度小,在Al中的扩散系数小,也不影响合金的可铸造性,因此极有希望替代钪成为铝合金中的添加剂。此外,钒在铝合金中相比于其它常见添加元素,其扩散率最小,在铝合金中形成VAl11等难溶化合物,在熔铸过程中起细化晶粒作用。并且也有细化再结晶组织、提高再结晶温度的作用。为进一步了解合金元素之间的作用机理及相关系,相图的研究显得极为重要。本工作主要采用平衡合金法,结合扫描电镜—能谱仪(SEM-EDS)和X-射线衍射仪(XRD)等对样品进行检测分析,并测定了Zr-Al-V三元系化合物在800℃等温截面下的相关系。在该体系中,发现一个新的三元化合物,命名为T相。经实验发现,Zr-Al-V体系在800℃等温截面共有15个三相区,分别为Al+Al3V+Al3Zr、Al8V5+Al3V+Al3Zr、Al8V5+T+Al3Zr、Al3Zr+T+Al2Zr、Al2Zr+T+V、Al2Zr+Al3Zr2+Al3Zr4、Al2Zr+Al3Zr4+Al2Zr3、Al2Zr+Al2Zr3+AlZr2、Al2Zr+AlZr2+AlZr3、Al2Zr+AlZr3+β-Zr、Al2Zr+V2Zr+β-Zr、Al2Zr+V2Zr+V、Al3Zr2+AlZr+Al3Zr、α-Zr+β-Zr+AlZr3和T+Al8V5+V。其中Al3Zr2+AlZr+Al3Zr、α-Zr+β-Zr+AlZr3和T+Al8V5+V三个三相区是从已有的实验数据中推导出来的。实验结果表明,在800℃下,T可与V,Al2Zr,Al3Zr,Al8V5平衡共存,它的成分范围是10.0~16.5 at.%Zr,52.8~55.2 at.%Al和29.3~36.3 at.%V。并且V在Al2Zr中的最大溶解度达54.1at.%。
[Abstract]:The development of heat-resistant aluminum material is an important research direction of aluminum alloy, among which scandium scum is the most effective additive for aluminum alloy. Only a small amount of addition can make aluminum alloy have extremely high strengthening effect and corrosion resistance. Excellent weldability and heat resistance. However, the price of scandium is very high, which leads to a very small range of applications, limited to sports and military. Because zirconium) can form a suitable strengthening phase in aluminum alloy, the solution in Al matrix is small at operating temperature, the diffusion coefficient in Al is small, and the castability of the alloy is not affected. Therefore, it is very promising to replace scandium as an additive in aluminum alloy. In addition, vanadium has the smallest diffusivity compared with other common elements in aluminum alloy, and forms insoluble compounds such as VAl11 in aluminum alloy, which plays a role in grain refinement in the process of melting and casting. It also has the function of refining recrystallization structure and increasing recrystallization temperature. In order to further understand the interaction mechanism and phase relationship between alloying elements, the study of phase diagram is very important. In this work, the equilibrium alloy method was used to determine the phase relationship of Zr-Al-V ternary compounds under isothermal section at 800 鈩，

本文编号：1975135