Processing of iron aluminides by pressureless sintering through Fe+Al elemental route

Gedevanishvili, S.; Deevi, S.C.

doi:10.1016/s0921-5093(01)01442-3

Cited by 100 publications

(73 citation statements)

References 27 publications

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“…It seems that as the aluminum melt reacts with titanium particles, some pores are left behind at the sites originally occupied by aluminum. Similar behavior has been attributed to the formation of pores during the synthesis of various aluminides from powder mixtures [31][32][33][34][35][36]. This is also in agreement with studies suggesting that the diffusion of aluminum atoms into titanium particles is the predominant mechanism governing the formation of titanium aluminides [21,22,[25][26][27].…”

Section: Tisupporting

confidence: 88%

Reactive synthesis and characterization of titanium aluminides produced from elemental powder mixtures

Sina

Iyengar

2015

J Therm Anal Calorim

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The formation of titanium aluminides in Ti-Al elemental powder mixtures containing 25, 50 and 75 at.% Al, has been studied using differential scanning calorimetry (DSC). Phase evolution in the mixture was followed by heating the compacted samples up to 1273 K at 7.5 and 15 K min -1 . The cooled samples were characterized using X-ray diffraction, scanning electron microscopy and energy-dispersive spectroscopy. The results showed that the primary combustion product in all the samples was TiAl 3 , and the combustion reaction occurred below the melting point of aluminum only in Ti-rich samples. In Alrich samples (75 at.% Al), TiAl 3 was obtained as a porous, single-phase product after combustion. In samples containing 25 and 50 at.% Al, the combustion reaction was incomplete and the unreacted titanium particles were covered by a layer of TiAl 3 . In these samples, other intermetallic compounds such as TiAl 2 , TiAl and Ti 3 Al were observed to form upon heating beyond the combustion peak and are attributed to the solid-state reaction between unreacted titanium and TiAl 3 . Heating the samples with 25 at.% Al to 1273 K for an hour led to the formation of a homogenous Ti 3 Al product, while a multiphase product with a dominant TiAl phase was observed in samples containing 50 at.% Al. Calculations based on DSC data show that the formation of TiAl 3 through the reaction between solid titanium and molten aluminum is associated with an apparent activation energy of 195 ± 20 kJ mol -1 and an enthalpy of -114 ± 5 kJ mol -1 .

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Section: Tisupporting

confidence: 88%

Reactive synthesis and characterization of titanium aluminides produced from elemental powder mixtures

Sina

Iyengar

2015

J Therm Anal Calorim

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“…So far researches have been focused mostly on thermite reaction between aluminum and iron above 900°C, and therefore, exothermic reactions below 700°C are usually neglected [15][16][17]19], although they obviously appear on some DSC curves. However, some authors reported these exothermic reactions at moderate temperatures, especially in context with fabrication of intermetallic materials from elemental Al-Fe powders, and putted them in relation with formation of Fe-Al solid solutions or intermetallic phases, such as FeAl 3 , FeAl 2 , Fe 2 Al 5 , Fe 3 Al or FeAl [18,[20][21][22][23][24][25].…”

Section: Dsc Investigationsmentioning

confidence: 99%

Optimizing the parameters for in situ fabrication of hybrid Al-Al2O3 composites

Nicoară

Locovei

Opriș

et al. 2016

J Therm Anal Calorim

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A new powder metallurgy technique was developed in order to increase the reinforcement proportion of aluminum with two different fractions of Al 2 O 3 . Aluminum powders were mixed with 20 % vol of alumina particles as primarily reinforcement, and additional alumina was produced in situ as a result of reaction between Al and additional 7.5 % vol of Fe 2 O 3 powder. The three grades of powders were milled and hot-pressed into small preforms, and differential scanning analysis (DSC) was performed to determine the kinetics of microstructural transformations produced on heating. DSC curves were mathematically processed to separate the superposing effects of thermal reactions. Transformation points on resulting theoretical curves evidenced two distinct exothermal reaction peaks close to the melting point of aluminum that were correlated with formation of Fe-Al compounds and oxidation of aluminum. Microstructural investigations by means of SEM-EDX and XRD suggested that these exothermal reactions produced complete decomposition of iron (III) oxide and formation of Fe-Al compounds during sintering at 700°C, and therefore, heating at higher temperatures would not be necessary. These results, along with calculation of activation energies, based on Kissinger's method, could be used to optimize the fabrication of Al-Al 2 O 3 composites by means of reactive sintering at moderate temperatures.

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“…In recent years, Fe-Al intermetallic compounds are attractive due to their unique properties such as low cost, low density, ease of fabrication, good high temperature mechanical property, excellent resistance to oxidation and corrosion, high electrical resistivity, as well as dual characteristics of both structural and functional materials etc [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. These properties have led to the identification of many potential uses, including high temperature structural materials, sintered porous gas-metal filters, heating elements, furnace fixtures, heat-exchanger piping, automobile and other industrial valve components, catalytic converter substrates, and components for molten salt applications [3][4][5]9,19,20].…”

Section: Introductionmentioning

confidence: 99%

“…These properties have led to the identification of many potential uses, including high temperature structural materials, sintered porous gas-metal filters, heating elements, furnace fixtures, heat-exchanger piping, automobile and other industrial valve components, catalytic converter substrates, and components for molten salt applications [3][4][5]9,19,20]. Therefore, in the past decades much effort was paid in the production of Fe-Al intermetallics, where the commonly used methods are melting/casting, mechanical alloying, combustion synthesis with thermo-mechanical treatment, and powder metallurgy (PM) etc [9,14,21], among which PM processing has increasingly attracted researchers' eyes due to its unique advantages in structure and size control, property improvement, and net shape or near net shape forming [14]. However, most studies in previous work using PM method for the preparation of Fe-Al intermetallics were mainly carried out in physical experiments.…”

mentioning

confidence: 99%

Double-action Die Compaction of Fe-Al Composite Powder- A Study by MPFEM Simulation

Li¹,

An²

2017

Proceedings of the 3rd Annual International Conference on Advanced Material Engineering (AME 2017)

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Abstract.To identify the densification process and corresponding mechanism, double-action die compaction of Fe-Al composite powder (with 20 wt.% Al) was modeled by multi-particle finite element method (MPFEM) from particulate scale in 2D. The initial packing structure generated by discrete element method (DEM) was input into FEM model where the mesh division of each particle was discretized. During compaction, macro and micro properties of the compacts were characterized and compared with those from single-action die compaction. The results show that with the same initial packing structure, double-action compaction can create dense compact with more uniform stress and relative density distributions at relatively low pressure. Densification mechanism analyses indicate that double-action compaction can more effectively improve the particle rearrangement to realize the dense packing structure compared with single action compaction when the pressure is low, in the former case large voids or pores have almost been eliminated, which is the precondition for the formation of high quality compact. With the increase of the pressure, further rearrangement and elastic and plastic deformation of Fe and Al particles can be observed; in this stage, the densification is mainly due to the plastic deformation of Al particles to fill their adjacent interstices. At high pressure, the compact shows bulk behavior, and some isolated enclosed pores are remained in the final compact. MPFEM simulation demonstrates that the final compact obtained in double-action compaction shows lower stresses/contact forces, and the stress distribution and particle deformation are more uniform. IntroductionIn recent years, Fe-Al intermetallic compounds are attractive due to their unique properties such as low cost, low density, ease of fabrication, good high temperature mechanical property, excellent resistance to oxidation and corrosion, high electrical resistivity, as well as dual characteristics of both structural and functional materials etc [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. These properties have led to the identification of many potential uses, including high temperature structural materials, sintered porous gas-metal filters, heating elements, furnace fixtures, heat-exchanger piping, automobile and other industrial valve components, catalytic converter substrates, and components for molten salt applications [3][4][5]9,19,20]. Therefore, in the past decades much effort was paid in the production of Fe-Al intermetallics, where the commonly used methods are melting/casting, mechanical alloying, combustion synthesis with thermo-mechanical treatment, and powder metallurgy (PM) etc [9,14,21], among which PM processing has increasingly attracted researchers' eyes due to its unique advantages in structure and size control, property improvement, and net shape or near net shape forming [14]. However, most studies in previous work using PM method for the preparation of Fe-Al intermetallics were mainly carried out in physical ex...

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Processing of iron aluminides by pressureless sintering through Fe+Al elemental route

Cited by 100 publications

References 27 publications

Reactive synthesis and characterization of titanium aluminides produced from elemental powder mixtures

Reactive synthesis and characterization of titanium aluminides produced from elemental powder mixtures

Optimizing the parameters for in situ fabrication of hybrid Al-Al2O3 composites

Double-action Die Compaction of Fe-Al Composite Powder- A Study by MPFEM Simulation

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