Thermal stability of Al2MgC2 and thermodynamic modeling of the Al–C–Mg system - Application to grain refinement of Mg–Al alloys

The synthesis of nanocrystalline Fe, Fe–4 wt% Al, and Fe–10 wt% Al solid solutions by SPEX ball milling has been studied. The microstructural evolution during ball milling, as well as subsequent heat treatment, has been characterized. The results demonstrate that ball milling promotes the formation of αFe–4 wt% Al and αFe–10 wt% Al solid solutions by reducing the activation energy of these alloys and generating thermal energy during this process. For Fe–10 wt% Al powders milled for various time intervals up to approximately 20 min, the FeAl intermetallic compound is formed. For alloys annealed at temperatures ranging from 600 to 1000 °C, the addition of 10 wt% Al to Fe significantly enhances the thermal stability of the nanocrystalline Fe–Al alloys. Interestingly, the addition of Al within the range of 4–10 wt% seems to have little effect on the thermal stability of these alloys annealed under the same conditions. Also, the thermal stability improves for alloys milled in air as opposed to those processed using Ar.

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The Effect of Erbium on the Properties and Microstructure of Al Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.706-709.329 ◽

2012 ◽

Vol 706-709 ◽

pp. 329-334 ◽

Cited By ~ 6

Author(s):

Zuo Ren Nie ◽

Hui Huang ◽

Kun Yuan Gao ◽

Bo Long Li ◽

Wei Wang ◽

...

Keyword(s):

Thermal Stability ◽

Tensile Strength ◽

Corrosion Resistance ◽

Pure Aluminum ◽

Fatigue Property ◽

Al Alloys ◽

Small Addition ◽

Excellent Corrosion Resistance ◽

Thermal Stability Of ◽

Strength And Ductility

Mechanical properties, corrosion resistance, and microstructure of Al alloys with trace element erbium were studied. Systemic studies in the pure aluminum and 5xxx series Al alloys showed that the tensile strength was significantly improved by above 20% with little loss of elongation by Er alloying. The 5xxx series Al alloys with erbium also exhibited excellent corrosion resistance. Erbium improved the aging hardness response of 7xxx series Al alloys and the addition of 0.4%Er to Al-Zn-Mg alloys increases the hardness by 35MPa. In all experiment Al alloys, a small addition of 0.1wt% Er induced a quick increase of the tensile strength and the amount of 0.4%Er shows optimized balance of the strength and ductility. The Er addition improved the thermal stability, with increasing the starting Rex temperature about 50°C in all investigated Al alloys. With regard to the microstructure mechanisms, in all experimental Al alloys Er addition has significantly refined the microstructure, which mainly attributed to presence the Al3Er particles. In the 7xxx series Al alloys, no observable PFZ after addition of 0.4% Er was found. The fatigue property, the fracture toughness and the thermal stability of microstructure and properties are on the way.

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Thermal Stability of Rapidly Quenched TI-NI-AL Amorphous Alloys

MRS Proceedings ◽

10.1557/proc-58-59 ◽

1985 ◽

Vol 58 ◽

Cited By ~ 3

Author(s):

K. Aoki ◽

K. Hiraga ◽

T. Masumoto

Keyword(s):

Thermal Stability ◽

Amorphous Phase ◽

Amorphous Alloys ◽

Melt Spinning ◽

Composition Range ◽

Amorphous Matrix ◽

Al Alloys ◽

The Other ◽

Molten State ◽

Thermal Stability Of

ABSTRACTTi-Ni-Al alloys were rapidly quenched from a molten state by the melt spinning method. Three kinds of metastable phases, namely, amorphous,nonequilibrium and quasicrystalline phases are formed in these alloys. The amorphous phase is formed in the range of 35 to 70 at% Ti and 0 to 25 at% Al. The nonequilibrium phases are formed in the composition range of 25 to 33 at% Ti. On the other hand, fine quasicrystalline phases are distributed in the amorphous matrix of the Ti-rich alloys. Crystallization temperatures and the hardness of the amorphous alloys were also examined.

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Thermal stability of phases in a NiCoCrAlY coating alloy

Journal of Materials Research ◽

10.1557/jmr.2008.0282 ◽

2008 ◽

Vol 23 (8) ◽

pp. 2264-2274 ◽

Cited By ~ 11

Author(s):

J.J. Liang ◽

H. Wei ◽

G.C. Hou ◽

Q. Zheng ◽

X.F. Sun ◽

...

Keyword(s):

Thermal Stability ◽

Temperature Dependence ◽

Experimental Observation ◽

Thermodynamic Modeling ◽

Thermodynamic Data ◽

Reasonable Agreement ◽

Temperature Dependent ◽

Thermal Stabilities ◽

Thermal Stability Of ◽

Coating Alloy

The temperature dependence of the thermal stability in a NiCoCrAlY coating alloy was examined by experimental observation and thermodynamic modeling in the 400–1200 °C temperature range. The results indicated that the thermal stabilities of primary β–NiAl, β–NiAl/α–Cr eutectic, and γ–Ni were slightly temperature dependent, but those of γ′–Ni3Al, σ–(Cr,Co,Ni), and α–Cr were strongly temperature dependent in the annealed NiCoCrAlY specimens. The temperature dependence of the thermal stabilities among γ′–Ni3Al, σ–(Cr,Co,Ni), and α–Cr might be ascribed to the σ → α transformation at ∼1100 °C and the γ′ → γ transformation at ∼800 °C. Further, using Thermocalc associated with TTNi7 database, thermodynamic equilibria were calculated. The modeling results were compared with the experimental results and found to be in reasonable agreement with the experimental observations of β–NiAl, σ–(Cr,Co,Ni), and γ′–Ni3Al. Some deviations observed are discussed in the light of both limited availability of thermodynamic data and experimental problems.

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