Synthesis, processing and properties of nanophase aluminide

Chang, Hsin-Yi; Hofler, J.; Altstetter, C. J.; Averback, Robert S

doi:10.1016/0921-5093(92)90269-7

Cited by 25 publications

(3 citation statements)

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“…The nanocrystalline materials, defined as polycrystalline solids having crystallite sizes usually less than 100 nm, can exhibit unique properties due to the large fraction of grain boundaries that they possess. In particular, the strength, ductility and diffusion kinetics, among other mechanical and chemical properties, may be significantly enhanced for nanocrystalline materials in comparison with materials with conventional grain sizes [1][2][3][4]. Intermetallic compounds based NiAl are being recognized as potential high temperature structural materials because of their low density (5.86 g/cm3), high melting point (1911 K) and excellent oxidation resistance up to 1573 K, as well as good thermal conductivity [5,6].…”

Section: Introductionmentioning

confidence: 99%

Study of Nanocrystalline NiAl Alloys Prepared by Mechanical Alloying

Gherib

Otmani

Djekoun

et al. 2012

DDF

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Nanostructured Powders of Ni-20wt%Al and Ni-50wt%Al Were Prepared, by Mechanical Alloying under an Argon Atmosphere, from Elemental Ni and Al Powders Using a Planetary Ball Mill (type Fritsch P7) for Different Times (0.5-24h).). Microstructural and Structural Features of the Final Products Were Characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). the Results of the XRD Shows the Formation of the B2 (Ni Al) Phase after 2 Hours of Milling for both Systems. Also Detected Was the Ni3al Phase in Ni80al20after 4 Hours. Crystallite Size Refinement of the Final Product Occurred down to Nanometer Scales when the Milling Time Increased, and Attained 17 Nm in the Ni50al50System and 20 Nm in the other System, at 24 Hours. this Decrease in Crystallite Size Is Accompanied by an Increase in the Interval Level Strain. the Kinetics of Al Dissolution during the Milling Process of Ni50al50System Can Be Described by Two Regimes, Characterised by Different Values of Avrami Parameters which Are Calculated by Using the Johnson–Mehl–Avrami Formalism.

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Section: Introductionmentioning

confidence: 99%

Study of Nanocrystalline NiAl Alloys Prepared by Mechanical Alloying

Gherib

Otmani

Djekoun

et al. 2012

DDF

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“…4 The synthesis of nanocrystalline materials has provided further avenues for improving the mechanical properties of metals. 5 Various methods have been applied to produce nanostructured titanium aluminides, such as consolidation of nanoparticles, [6][7][8] crystallisation of amorphous solids, 9 ball milling or mechanical alloying 10,11 and severe plastic deformation, 12,13 among which consolidation of nanoparticles is believed to be most suitable for industrial application since it is possible to produce bulk samples and final components by near net shape forming. On the other hand, recent three-dimensional printing technology provides a promising method for fabrication of metallic components with complex shapes, by laser melting of the alloy powders.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of nanoparticles of titanium aluminides by hydrogen plasma–metal reaction: effects of master alloy composition and chamber pressure on particle size, composition and phase

Mei

2015

Powder Metallurgy

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Hydrogen plasma-metal reaction (HPMR) method is applied successfully for large scale synthesis of nanoparticles of titanium aluminides, from binary Ti-Al master alloys with Al content varying from 5 to 75 at-%. The average size, phase constitution and chemical composition of the as synthesised nanoparticles are characterised and related to the master alloy composition and processing parameters. Results show that Al content in the as synthesised nanoparticles deviates positively from that of the master alloy. The maximum generation rates of Al and Ti occur at Al content about 35 and 20 at-% in the master alloy respectively. The average size of the nanoparticles increases with increasing Al content in the master alloy, with a peak at 35-45 at-%; for the same Al content, it increases with increasing chamber pressure and saturates at the chamber pressure of 0.080 MPa.

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“…superplastic behavior) because of large fraction of grain boundaries with high concentration of defects that the spacing between them approaches inter-atomic distances [4,7]. It has been reported that strength, ductility and diffusion kinetics may be significantly enhanced for nanomaterials [8][9]. Besides grain size refinement, high energy ball milling can be used for mechanical alloying (MA) of elemental powder mixtures on an atomic scale.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Nanocrystalline Ni<sub>3</sub>Al Intermetallic via Mechanical Alloying and Reaction Synthesis

Ismail

Yaacob

2006

KEM

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Stoichiometric nanocrystalline Ni3Al was prepared by mechanical alloying of elemental Ni and Al powders under argon gas atmosphere for different time (4-48h). The nanostructured Ni3Al powders were consolidated into bulk compacts and sintered in a small DTA furnace under flowing Argon to observe the exothermic reaction between the stoichiometric Ni and Al. The estimated crystallite size showed that the mechanically alloyed Ni3Al grain size decrease from 127 nm to 9.36nm with increasing mechanical alloying time from 4h to 48h. Agglomerations of the powder particles prevalently occurred as observed from the SEM micrographs. Saturation magnetization, Ms value of the mechanically alloyed powders decreases as milling time increases due to smaller amount of elemental nickel responding to the applied fields. Following reaction synthesis of the compacted powders, thermal profile analysis revealed the presence of exothermic peaks in the DTA curves at about 400oC. Relative densities of the sintered compact were measured and found to be from 77- 88% with the exception for the 48h mechanically alloyed sintered compact from milling balls contaminations. XRD results of the sintered compacts mechanically alloyed for 18h and above revealed the formation of pure nanocrystalline Ni3Al. Crystallites size estimations showed the occurrence of grain growth during sintering.

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Synthesis, processing and properties of nanophase aluminide

Cited by 25 publications

References 0 publications

Study of Nanocrystalline NiAl Alloys Prepared by Mechanical Alloying

Study of Nanocrystalline NiAl Alloys Prepared by Mechanical Alloying

Synthesis of nanoparticles of titanium aluminides by hydrogen plasma–metal reaction: effects of master alloy composition and chamber pressure on particle size, composition and phase

Synthesis and Characterization of Nanocrystalline Ni<sub>3</sub>Al Intermetallic via Mechanical Alloying and Reaction Synthesis

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