New generation of eutectic Al-Ni casting alloys for elevated temperature services

Suwanpreecha, Chanun; Pandee, Phromphong; Patakham, Ussadawut; Limmaneevichitr, Chaowalit

doi:10.1016/j.msea.2017.10.034

Cited by 128 publications

(31 citation statements)

References 38 publications

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“…The addition of Re and Ce had led to their segregation at the interface that can lower the interface energy and significantly reduces the coarsening rate. Recently, an addition of Sc is shown to have an effect on retaining strength at high temperature in the Al-Al 3 Ni eutectic [12,39]. In the present investigation, we could obtain a clear evidence of Zr segregation at the eutectic a-Al/Al 3 Ni interface through APT measurements.…”

Section: Tablesupporting

confidence: 50%

“…Addition of transition metals (TM) like Sc, Zr and V, resulted in precipitation of strengthening coherent intermetallic phases of L1 2 ordered structure with the stoichiometry through the eutectic composite can be promising and has been explored in recent time. It was shown that addition of Sc or Zr/V to Al-based eutectic cast alloys has resulted in an improvement in mechanical properties that is attributed mainly to the precipitation of coherent Al 3 Zr, Al 3 Sc or Al 3 (Zr,V) precipitates in a-Al matrix [12,16,19,38,39]. In particular, the addition of Sc is shown recently to significantly improve the mechanical properties including creep properties of Al-Al 3 Ni eutectic alloy [39].…”

Section: Introductionmentioning

confidence: 99%

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On the origin of a remarkable increase in the strength and stability of an Al rich Al-Ni eutectic alloy by Zr addition

et al. 2019

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The effect of Zr addition to Al rich binary a-Al-Al 3 Ni eutectic cast alloy (Al-3.1 at.% Ni) in enhancing the microstructural stability and strength at high temperature is demonstrated. On subsequent heat treatment after casting, nanometric coherent L1 2 ordered Al 3 Zr precipitates form inside the a-Al that strengthen the alloy. Additionally, remarkable stability of eutectic microstructure was observed even after 100 h of annealing at 400 C. The synergetic effect of the strengthening of the a-Al matrix by coherent Al 3 Zr precipitates and the low coarsening rate of the Al 3 Ni rods results in a significant increase in high temperature hardness and yield strength of the alloy. The tensile yield strength of the annealed Al-3.1Ni-0.15Zr alloy (400 C, 10 h) tested at 250 C is found to be 185 ± 10 MPa, which is 1.5 times higher than the corresponding binary Al-3.1Ni alloy. The experimentally determined average rod size (radius) during annealing at 400 C follows the classical matrix diffusion controlled LSW-based coarsening model for both binary Al-3.1Ni and ternary Al-3.1Ni-0.15Zr alloys. The calculated coarsening rate constant values based on modified LSW coarsening model are 10.3 and 4.1 nm 3 /s for Al-3.1Ni and Al-3.1Ni-0.15Zr alloys, respectively. Atom probe tomographic (APT) investigations of the heat-treated ternary alloy unambiguously reveal segregation of Zr solute at the aAl/Al 3 Ni interface in addition to the presence of the strengthening Al 3 Zr ordered precipitates in the a-Al matrix. The segregation hinders the interdiffusion of Al and Ni in the eutectic and, thereby, increasing the stability of the eutectic phase at high temperature.

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Section: Tablesupporting

confidence: 50%

Section: Introductionmentioning

confidence: 99%

On the origin of a remarkable increase in the strength and stability of an Al rich Al-Ni eutectic alloy by Zr addition

et al. 2019

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“…However, despite thermally stable precipitates, the Al–Si eutectic imposes a limit on the alloy stability improvement. To overcome this barrier, the Al–Al 3 Ni eutectic was introduced [ 3 , 4 ] with better thermal stability, attributed to the diffusion coefficient of Ni in Al, being lower by about two orders of magnitude and higher eutectic temperature [ 5 ]. A possibility of further improvement is anticipated through a substitution of nickel with rare-earth metal cerium [ 6 , 7 ], having the diffusion coefficient in Al lower by approximately four orders of magnitude than that for Ni in Al [ 8 ].…”

Section: Introductionmentioning

confidence: 99%

On the Al–Al11Ce3 Eutectic Transformation in Aluminum–Cerium Binary Alloys

Czerwiński

Amirkhiz

2020

Materials

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The L ↔ Al + Al11Ce3 technologically important eutectic transformation in Al–Ce binary alloys, containing from 5 to 20 wt.% Ce and ranging from hypo- to hypereutectic compositions, was examined along with the microstructure and properties of its solidified product. A combination of thermal analysis and metallography determined the coordinates of the eutectic point at 644.5 ± 0.6 °C and 10.6 wt.% Ce, clarifying the existing literature ambiguity. Despite the high entropy of melting of the Al11Ce3 phase, in hypoeutectic alloys the eutectic was dominated by the regular morphology of periodically arranged lamellae, typical for non-faceted systems. In the lamellar eutectic, however, the faceting of Al11Ce3 was identified at the atomic scale. In contrast, for hypereutectic compositions, the Al11Ce3 eutectic phase exhibited complex morphology, influenced by the proeutectic Al11Ce3 phase. The Al11Ce3 eutectic phase lost its coherency with Al; it was deduced that a partial coherency was present only at early stages of lamellae growth. The orientation relationships between the Al11Ce3 and Al in the eutectic structure, leading to partial coherency, were determined to be Al ║ Al11Ce3 with Al ║ Al11Ce3 and Al ║ Al11Ce3 with Al ║ Al11Ce3. The Al11Ce3 phase with a hardness of 350 HV and Al matrix having 35 HV in their eutectic arrangement formed in situ composite, with the former playing a role of reinforcement. However, the coarse and mostly incoherent Al11Ce3 eutectic phase provided limited strengthening and the Al–Ce alloy consisting of 100% eutectic reached at room temperature a yield stress of just about 70 MPa.

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“…The presently used Al−Si eutectic with low melting range limits the stability improvement [35]. To overcome this barrier, the Al−Al 3 Ni eutectic was proposed [112][113][114] with better thermal stability, attributed, according to the work in [112], to the existence of a thin coherent layer of α−Al surrounding each Al 3 Ni fiber. However, among other issues of Ni, the fluidity of the Al−Al 3 Ni eutectic, tested in the Al−6Ni−4Mn (wt.%) alloy, was not as high as that of typical casting alloys, e.g., A390.…”

Section: Eutectic Based On Al−ni Systemmentioning

confidence: 99%

Thermal Stability of Aluminum Alloys

Czerwiński

2020

Materials

132

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Thermal stability, determining the material ability of retaining its properties at required temperatures over extended service time, is becoming the next frontier for aluminum alloys. Its improvement would substantially expand their range of structural applications, especially in automotive and aerospace industries. This report explains the fundamentals of thermal stability; definitions, the properties involved; and the deterioration indicators during thermal/thermomechanical exposures, including an impact of accidental fire, and testing techniques. For individual classes of alloys, efforts aimed at identifying factors stabilizing their microstructure at service temperatures are described. Particular attention is paid to attempts of increasing the current upper service limit of high-temperature grades. In addition to alloying aluminum with a variety of elements to create the thermally stable microstructure, in particular, transition and rare-earth metals, parallel efforts are explored through applying novel routes of alloy processing, such as rapid solidification, powder metallurgy and additive manufacturing, engineering alloys in a liquid state prior to casting, and post-casting treatments. The goal is to overcome the present barriers and to develop novel aluminum alloys with superior properties that are stable across the temperature and time space, required by modern designs.

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New generation of eutectic Al-Ni casting alloys for elevated temperature services

Cited by 128 publications

References 38 publications

On the origin of a remarkable increase in the strength and stability of an Al rich Al-Ni eutectic alloy by Zr addition

On the origin of a remarkable increase in the strength and stability of an Al rich Al-Ni eutectic alloy by Zr addition

On the Al–Al11Ce3 Eutectic Transformation in Aluminum–Cerium Binary Alloys

Thermal Stability of Aluminum Alloys

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