Experimental Investigation and Thermodynamic Assessment of the Ternary Al–Ni–Er System

Abstract

Al–Ni–Er is an essential system in heat-resistant Al alloys. However, the aluminum-rich corner of this system, which has the most practical application significance, has not been fully studied. In this work, the phase equilibria of the Al–Ni–Er system are investigated via experiments and thermodynamic modeling. The isothermal sections of the Al-rich corner of this ternary system at 600 and 700 °C were determined through equilibrated alloys combined with scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and X-ray diffractometry (XRD). In addition, the vertical sections of the Al–Ni–Er system at Al0.7Ni0.3–Al0.7Er0.3 and Al0.8Ni0.2–Al0.8Er0.2 were measured via differential scanning calorimetry (DSC) analysis. A new ternary compound, τ14-Al12Ni2Er3, was discovered. On the basis of the experimental results of this and previous studies, the ternary Al–Ni–Er system was optimized with the calculation of phase diagrams (CALPHAD) method. The calculated isothermal and vertical section phase diagrams of the ternary system are in good agreement with experimental and literature data.

Effect of Vanadium Addition on Solidification Microstructure and Mechanical Properties of Al–4Ni Alloy

“…The study by Gan et al [15] shows that trace amounts of Co addition (0.1 at%) could refine the Al 3 Ni fibers under both normal gravitational and super-gravitational fields. Sankanit et al [16] found that the eutectic Al 3 Ni phases could be transformed into a Al 9 (Ni,Mn) 2 phase by adding Mn into Al-Ni alloy; the Al-4Ni-1Mn-0.36Sc-0.06Zr alloy exhibited excellent thermal stability up to a maximum temperature of 350 • C. Rare earth elements such as Yb [17], Sc [18], and Er [19] could effectively refine the microstructure and improve the properties of Al-Ni alloys.…”