Microstructure, Fabrication and Properties of Quasicrystalline Al—Cu—Fe Alloys: A Review

Huttunen-Saarivirta, Elina

doi:10.1002/chin.200411216

Cited by 22 publications

(32 citation statements)

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“…After this process, chemical treatments are applied during some hours at temperatures above 300ºC in environment or in other medium. Samples are then characterized by using X -ray photoelectron spectroscopy (XPS) and Xray stimulated Auger electron spectroscopy (XAES) [4]. According to Figure 1 and the second PINHEIRO et al [5], pure metals used to form quasicrystalline alloys suffer oxidation under several conditions; i.e., in vacuum, in normal air and after liquid immersion.…”

Section: Introductionmentioning

confidence: 99%

THERMODYNAMIC STUDY OF IRON IN ALLOYS OF QUASICRYSTALLINE AlCuFe

Nascimento

Gostinho

Cavalcanti

2013

J. Chil. Chem. Soc.

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Solid iron can be observed at environmental conditions and also as metallic component of quasicrystalline alloys. Its behavior in aqueous solution is analyzed from some particular thermochemical relationships. The model utilizes free Gibbs energy to obtain pH and pε parameters which are related to iron redox reactions. The solid iron system, defined as Fe (s) : Fe 2+ -Fe 3+ -Fe 2 O 3 (hematite) -Fe 3 O 4 (magnetite), was modelled by considering a low molar concentration and environmental temperature. In order to obtain pε values, equations relating Gibbs standard free energy and equilibrium constants were applied. A stability diagram such as pε x pH was chosen to depict these thermochemical relationships. Thus, straight line dpε/dpH slopes were obtained for each process step of the solid iron system. In systems relating solid iron to iron species Fe 2+ and Fe 3+ the slopes are equal to zero; i.e. horizontal line shows the iron species dominance in some specific pH (hydronium ions) range. The negative values obtained show the pH dependence of the iron species investigated. In natural water environment, it is possible to distinguish hematite formation from magnetite formation. However in quasicrystalline AlCuFe alloys the last iron species formed is hematite which ion pairs to copper. Due to the strong hydronium ions (pH) dependence, it is necessary to measure it both in environmental conditions and quasicrystalline phase's formation. Considering that the temperature adopted was 25°C, the results are valid only for this temperature.

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Section: Introductionmentioning

confidence: 99%

THERMODYNAMIC STUDY OF IRON IN ALLOYS OF QUASICRYSTALLINE AlCuFe

Nascimento

Gostinho

Cavalcanti

2013

J. Chil. Chem. Soc.

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“…It has been seen in many alloy systems that a prolonged post-annealing is required to lead to a single phase. It has also been reported [1] that no single phase icosahedral structure is possible in Al 62 Cu 25.5 Fe 12.5 (at%) system without further heat treatments. However, a cooling rate of 10 6 Ks -1 or higher can be used to directly produce icosahedral single phase in Al 62 Cu 25.5 Fe 12.5 (at%) system.…”

Section: Introductionmentioning

confidence: 94%

“…The Al--Cu--Fe alloy system in the composition range of 58--70 at% Al and 20--28 at% Cu and 10--14 at% Fe, containing stable quasicrystalline (QC) phases, has been extensively studied [1][2][3][4][5][6][7]. In general, the processing routes employed for such materials are restricted to melt spinning [3], melt atomization [8], mechanical alloying [4][5][6][7] and plasma spraying [9].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of single phase i-AlCuFe bulk quasicrystal by spray forming

Srivastava¹,

Uhlenwinkel

Schulz

et al. 2008

Zeitschrift Für Kristallographie

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Abstract. In the present study, an icosahedral single phase bulk quasicrystalline material based on Al 62 Cu 25.5 Fe 12.5 has been synthesised by a spray forming route. Microstructural characterization showed an average grain size of 10 mm. The oversprayed fine powder showed the presence of b-and lphases, whereas, the deposit consited of the fully single phase bulk quasicrystalline material with compositional homogeneity. The hardness and fracture toughness measurements were carried out at different indentation loads of 50-500 g. The hardness values varied in the range 10.4-8.1 GPa and fracture toughness was seen to decrease with increasing load. The varionan of hardness with load, which is known as indentation size effect (ISE), has been established clearly. Fracture toughness value was constant in the load range from 200 to 500 g at 1.2 MPa m 1/2 . The cracking pattern after indentation at higher load has been observed to be intergranular as well as transgranular. The evolution of the single phase bulk quasicrystalline material has been discussed in light of the unique combination of atomization and deposition process elements in spray forming technique.

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“…It is known that the quasicrystalline phase has a number of advantages such as low growth rate, high resistance to elastic and plastic deformations, high heat-resistant strength, high wear resistance, low coefficient of thermal expansion, low thermal conductivity, isotropic properties, pseudo spherical morphology, Al-rich composition, isolated homogeneous dispersion surrounded by Al, dissolution of many solute elements and high corrosion resistance etc [34][35][36] . By utilizing these advantages, we have been trying to develop a new type of Al-based alloy containing quasicrystalline phase as a main constituent phase 37 .…”

Section: Al-based Nano-quasicrystalline Alloysmentioning

confidence: 99%

Development and Applications of Highly Functional Al-based Materials by Use of Metastable Phases

et al. 2015

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In recent years, there has been a strong demand of developing advanced structural materials with functional properties such as high specific strength, high elevated temperature specific strength, high fatigue specific strength, low corrosion loss and low wear loss. This is because the practical uses of these functional structure materials are expected to cause the saving of material amount, reductions of material cost and energy during material production as well as the saving of consuming energy during practical uses. Besides, the light-weight materials with high corrosion resistance and high wear resistance are effective for the increase of endurance limit and the lightening of final products. Thus, the development of novel Al-based alloys having simultaneously the above-described functional properties is particularly important nowadays.As strengthening mechanisms for Al-based alloys, the following seven mechanisms are generally known 1 : solid solution, grain size refinement, work hardening, age hardening, precipitation, dispersion and defect-induced solute segregation. We have also noticed that the use of rapid quenching enables highly supercooled liquid solidification in conjunction with a high nucleation rate and low growth rate. By utilizing the high nucleation rate and low growth rate phenomenon, we have synthesized various kinds of metastable phases which change from nanocrystalline base structure to bulk glassy base structure through an amorphous base structure with increasing quenching effect (cooling rate). It is also known that the quenching effect is dominated by cooling rate from melt resulting from rapid solidification processes as well as by supercooling capacity of alloy liquid depending on alloy component and composition.When we focus on the strengthening caused by metastable phases, the effect is due to the combination of solid solution + ultra-high density of defects for amorphous phase and dispersion + grain size refinement + segregation for nanocrystalline phase. The amorphous plus nanocrystalline mixed phase alloys are expected to have simultaneously almost all the strengthening mechanisms. By utilizing the combined strengthening mechanisms of these metastable phases, we have tried to prepare novel Al-based alloys with the high tensile strength exceeding 1500 MPa at room temperature, high elevated temperature strength above 500 MPa at 573 K, high rotating beam fatigue strength above 400 MPa at 10 7 cycles, high elevated temperature fatigue strength above 100 MPa at 673 K after 10 6 cycles and high corrosion resistance below 20 mm/year in 0.25 M NaOH aqueous solution at 293 K. In addition, these Al-based alloys have been requested to exhibit a low wear loss, low coefficient of thermal expansion and low material density etc. This paper presents the review of the development achievements of metastable Al-based alloys obtained in our group on the basis of the above-described backgrounds and objectives. This paper reviews the features of alloy components, structure and mechanical properties, p...

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Microstructure, Fabrication and Properties of Quasicrystalline Al—Cu—Fe Alloys: A Review

Abstract: For Abstract see ChemInform Abstract in Full Text.

Cited by 22 publications

References 1 publication

THERMODYNAMIC STUDY OF IRON IN ALLOYS OF QUASICRYSTALLINE AlCuFe

THERMODYNAMIC STUDY OF IRON IN ALLOYS OF QUASICRYSTALLINE AlCuFe

Synthesis of single phase i-AlCuFe bulk quasicrystal by spray forming

Development and Applications of Highly Functional Al-based Materials by Use of Metastable Phases

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