Al-Ni-Er三元体系相平衡研究

Phase equilibrium investigation of the Al-Ni-Er ternary system

高强铝合金具有密度低、强度高、热加工性能好等优点,是航空航天领域的主要结构材料。现代航空航天工业的发展,对高强铝合金的强度和综合性能提出了更高要求。研究和应用双相纳米结构铝合金离不开精确可靠的相图信息。通过X射线衍射(XRD),扫描电子显微镜(SEM)和电子探针显微分析(EPMA/WDS),对Al-Ni-Er三元体系在400℃下的相平衡进行了实验研究。结果表明:①在平衡合金样品中发现了新的三元化合物τ11-AlNiEr4,τ12-AlNi6Er13和τ13-AlNi2Er;②化合物τ5,τ10,τ13,AlNi3,AlNi,Al3Ni2,Al2Er,ErNi2和ErNi5具有一定范围的固溶度。400℃时,Ni在Al2Er中的固溶度为8.93%(原子分数),Al在ErNi2中的固溶度为2.00%(原子分数);③CaCu5-ErNi5是连续固溶体,对Al的最大固溶度为33.33%(原子分数)。

High-strength aluminum alloy has the advantages of low density,high strength,and good thermal processing performance.It is the main structural material in the aerospace field.The development of modern aerospace industry has put forward higher requirements for the strength and comprehensive performance of high-strength aluminum alloys.The research and application of dual-phase nanostructured aluminum alloys are inseparable from accurate and reliable phase diagram information.Phase equilibria of the Al-Ni-Er ternary system at 400℃were experimentally investigated through X-ray diffraction,scanning electron microscopy and electron probe micro-analysis.①New ternary compoundsτ11-AlNiEr4,τ12-AlNi6Er13 andτ13-AlNi2Er were discovered in the equilibrated alloy samples.②Compoundsτ5,τ10,τ13,AlNi3,AlNi,Al3Ni2,Al2Er,ErNi2 and ErNi5 have a certain range of solid solubility.The solid solubility of Ni in Al2Er is 8.93 at.%and the solid solubility of Al in ErNi2 is 2.00 at.%at 400℃.③Experiments have verified that CaCu5-ErNi5 is a continuous solid solution and the maximum solubility of Al is up to 33.33 at.%.