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T Kulik - One of the best experts on this subject based on the ideXlab platform.
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nanocrystalline or Amorphous matrix al60fe15ti15 co mg zr 5 5 b composites produced by consolidation of mechanically alloyed powders lightweight materials with high hardness
Intermetallics, 2012Co-Authors: Marek Krasnowski, T KulikAbstract:Abstract Al60Fe15Ti15(Co/Mg/Zr)5B5 powder mixtures were subjected to mechanical alloying. XRD investigations revealed presence of an Amorphous Structure in the milling products. The calorimetric study showed that the crystallisation onset temperature of Amorphous phase is 549 °C, 566 °C and 587 °C for the alloys containing Co, Mg and Zr respectively. The milled powders were consolidated under a pressure of 7.7 GPa in different conditions: at the temperature 40 °C below the crystallisation onset temperature and at 1000 °C. An Amorphous Structure was retained after consolidation applied at the lower temperature. Compaction at 1000 °C caused crystallisation of an Amorphous phase into Al5Fe2 and/or τ2 intermetallic phases, depending on the alloy composition. Structural examinations revealed that all the bulk samples are composites with boron particles embedded in Amorphous or nanocrystalline matrix. The hardness of the nanocrystalline matrix composites is in the range of 9.46–9.83 GPa whereas that of Amorphous matrix ones is in the range of 8.43–8.65 GPa, depending on the composition. The specific yield strength of the produced samples, estimated using the Tabor relation, is in the range of 689–830 kN m/kg and the highest value is possessed by the nanocrystalline matrix composite containing Mg. We also suppose that application of high pressure affected crystallisation of an Amorphous phase, influencing the phase composition of the products of this process.
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bulk Amorphous al85fe15 alloy and al85fe15 b composites with Amorphous or nanocrystalline matrix produced by consolidation of mechanically alloyed powders
Intermetallics, 2011Co-Authors: Marek Krasnowski, A Antolakdudka, T KulikAbstract:Abstract An Al80Fe14B6 powder mixture was subjected to mechanical alloying. Presence of an Amorphous Structure in the milling product was revealed by XRD investigations. The calorimetric study showed that the Amorphous phase crystallised above 370 °C. The milled Al 80 Fe 14 B 6 powder was consolidated under a pressure of 7.7 GPa in different conditions: at 350 °C and at 1000 °C. Besides, the mechanically alloyed Amorphous Al 85 Fe 15 powder was consolidated at 360 °C. The Amorphous Structure was retained after consolidation applied at 350 °C and 360 °C. Compaction at 1000 °C caused crystallisation of the Amorphous phase and appearance of metastable nanocrystalline phases. Structural investigations revealed that both bulk Al 80 Fe 14 B 6 samples are composites with boron particles embedded in Amorphous or nanocrystalline matrix. The hardness of the nanocrystalline-matrix composite and of the Amorphous-matrix one is equal to 707 HV1 and 641 HV1 respectively, whereas that of bulk Amorphous Al 85 Fe 15 alloy is 504 HV1. The specific yield strength of Amorphous-matrix and nanocrystalline-matrix composites, estimated using the Tabor relationship, is 625 and 650 kNm/kg respectively, while that of Amorphous Al 85 Fe 15 alloy is 492 kNm/kg. We also suppose that application of high pressure affected crystallisation of Amorphous phase, influencing the phase composition of the products of this process.
R Z Valiev - One of the best experts on this subject based on the ideXlab platform.
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evolution of the Amorphous Structure in melt spun ti50ni25cu25 alloy subjected to high pressure torsion deformation
Intermetallics, 2015Co-Authors: D V Gunderov, Anna Churakova, Yu V Slesarenko, а V Lukyanov, E P Soshnikova, V G Pushin, R Z ValievAbstract:Abstract Peculiarities of Structure and mechanical behaviour of Amorphous Ti 50 Ni 25 Cu 25 alloy were the focus of this research. The melt-spun ribbons of Amorphous Ti 50 Ni 25 Cu 25 were subjected to high pressure torsion (HPT) at temperatures of 20–150 °C in order to modify their Structure and mechanical behaviour. Some features of obtained HPT-processed samples were compared with initial state with the help of x-ray diffraction (XRD), transmission electron microscopy (TEM) and nanohardness testing. Analysis of structural data and mechanical behaviour allowed us to assume that severe plastic deformation (SPD) processing of melt-spun Ti 50 Ni 25 Cu 25 alloy might lead to the formation of the Structure similar to the new kind of noncrystalline state – “nanoglass” state.
Marek Krasnowski - One of the best experts on this subject based on the ideXlab platform.
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nanocrystalline or Amorphous matrix al60fe15ti15 co mg zr 5 5 b composites produced by consolidation of mechanically alloyed powders lightweight materials with high hardness
Intermetallics, 2012Co-Authors: Marek Krasnowski, T KulikAbstract:Abstract Al60Fe15Ti15(Co/Mg/Zr)5B5 powder mixtures were subjected to mechanical alloying. XRD investigations revealed presence of an Amorphous Structure in the milling products. The calorimetric study showed that the crystallisation onset temperature of Amorphous phase is 549 °C, 566 °C and 587 °C for the alloys containing Co, Mg and Zr respectively. The milled powders were consolidated under a pressure of 7.7 GPa in different conditions: at the temperature 40 °C below the crystallisation onset temperature and at 1000 °C. An Amorphous Structure was retained after consolidation applied at the lower temperature. Compaction at 1000 °C caused crystallisation of an Amorphous phase into Al5Fe2 and/or τ2 intermetallic phases, depending on the alloy composition. Structural examinations revealed that all the bulk samples are composites with boron particles embedded in Amorphous or nanocrystalline matrix. The hardness of the nanocrystalline matrix composites is in the range of 9.46–9.83 GPa whereas that of Amorphous matrix ones is in the range of 8.43–8.65 GPa, depending on the composition. The specific yield strength of the produced samples, estimated using the Tabor relation, is in the range of 689–830 kN m/kg and the highest value is possessed by the nanocrystalline matrix composite containing Mg. We also suppose that application of high pressure affected crystallisation of an Amorphous phase, influencing the phase composition of the products of this process.
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bulk Amorphous al85fe15 alloy and al85fe15 b composites with Amorphous or nanocrystalline matrix produced by consolidation of mechanically alloyed powders
Intermetallics, 2011Co-Authors: Marek Krasnowski, A Antolakdudka, T KulikAbstract:Abstract An Al80Fe14B6 powder mixture was subjected to mechanical alloying. Presence of an Amorphous Structure in the milling product was revealed by XRD investigations. The calorimetric study showed that the Amorphous phase crystallised above 370 °C. The milled Al 80 Fe 14 B 6 powder was consolidated under a pressure of 7.7 GPa in different conditions: at 350 °C and at 1000 °C. Besides, the mechanically alloyed Amorphous Al 85 Fe 15 powder was consolidated at 360 °C. The Amorphous Structure was retained after consolidation applied at 350 °C and 360 °C. Compaction at 1000 °C caused crystallisation of the Amorphous phase and appearance of metastable nanocrystalline phases. Structural investigations revealed that both bulk Al 80 Fe 14 B 6 samples are composites with boron particles embedded in Amorphous or nanocrystalline matrix. The hardness of the nanocrystalline-matrix composite and of the Amorphous-matrix one is equal to 707 HV1 and 641 HV1 respectively, whereas that of bulk Amorphous Al 85 Fe 15 alloy is 504 HV1. The specific yield strength of Amorphous-matrix and nanocrystalline-matrix composites, estimated using the Tabor relationship, is 625 and 650 kNm/kg respectively, while that of Amorphous Al 85 Fe 15 alloy is 492 kNm/kg. We also suppose that application of high pressure affected crystallisation of Amorphous phase, influencing the phase composition of the products of this process.
T G Nieh - One of the best experts on this subject based on the ideXlab platform.
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plasticity and structural instability in a bulk metallic glass deformed in the supercooled liquid region
Acta Materialia, 2001Co-Authors: T G NiehAbstract:Abstract The deformation behavior of a bulk Amorphous Zr–10Al–5Ti–17.9Cu–14.6Ni alloy was characterized in the supercooled liquid region. The alloy was observed to exhibit Newtonian behavior at low strain rates but to become non-Newtonian at high strain rates. Structures of the Amorphous material, both before and after deformation, were examined using X-ray diffraction and high-resolution electron microscopy. Experimental results showed the presence of nanocrystallites in the deformed samples, suggesting that the non-Newtonian behavior was associated with the concurrent crystallization of the Amorphous Structure during deformation; that is, a mixed crystalline-plus-Amorphous Structure was being tested. A mechanistic model based upon structural evolution has been developed to interpret the observed non-Newtonian behavior.
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plasticity and structural instability in a bulk metallic glass deformed in the supercooled liquid region
Acta Materialia, 2001Co-Authors: T G Nieh, J Wadsworth, C T Liu, T Ohkubo, Yoshihiko HirotsuAbstract:Abstract The deformation behavior of a bulk Amorphous Zr–10Al–5Ti–17.9Cu–14.6Ni alloy was characterized in the supercooled liquid region. The alloy was observed to exhibit Newtonian behavior at low strain rates but to become non-Newtonian at high strain rates. Structures of the Amorphous material, both before and after deformation, were examined using X-ray diffraction and high-resolution electron microscopy. Experimental results showed the presence of nanocrystallites in the deformed samples, suggesting that the non-Newtonian behavior was associated with the concurrent crystallization of the Amorphous Structure during deformation; that is, a mixed crystalline-plus-Amorphous Structure was being tested. A mechanistic model based upon structural evolution has been developed to interpret the observed non-Newtonian behavior.
D V Gunderov - One of the best experts on this subject based on the ideXlab platform.
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enhanced strain rate sensitivity of zr based bulk metallic glasses subjected to high pressure torsion
Journal of Alloys and Compounds, 2018Co-Authors: E V Boltynjuk, D V Gunderov, E V Ubyivovk, M A Monclus, L W Yang, J M Molinaaldareguia, A I Tyurin, A R Kilmametov, Anna Churakova, Yu A ChuryumovAbstract:Abstract The Zr62Cu22Al10Fe5Dy1 bulk metallic glass (BMG) was subjected to high pressure torsion (HPT) at room temperature. The state after HPT processing demonstrates presence of large number of heterogeneities in Amorphous Structure – shear bands. Nanoindentation was used to study the effect of HPT processing on deformation behavior and strain rate sensitivity (m). It was found that HPT significantly affects mechanical behavior of BMG during nanoindentation. Decrease in hardness and Young's modulus was observed after HPT. At the same time HPT processing led to an increase in m from 0.014 for the as-cast material to 0.036. The lack of serration flow and shear bands around imprints was observed in addition to above mentioned changes. A much less localized deformation mode under nanoindentation along with an increase in values of strain rate sensitivity of HPT-processed state in comparison with the initial state imply homogeneous deformation behavior after processing. The observed drastic changes in deformation behavior and Structure can be explained as the formation of a highly-heterogeneous Amorphous Structure resembling nanoglasses in result of HPT processing.
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evolution of the Amorphous Structure in melt spun ti50ni25cu25 alloy subjected to high pressure torsion deformation
Intermetallics, 2015Co-Authors: D V Gunderov, Anna Churakova, Yu V Slesarenko, а V Lukyanov, E P Soshnikova, V G Pushin, R Z ValievAbstract:Abstract Peculiarities of Structure and mechanical behaviour of Amorphous Ti 50 Ni 25 Cu 25 alloy were the focus of this research. The melt-spun ribbons of Amorphous Ti 50 Ni 25 Cu 25 were subjected to high pressure torsion (HPT) at temperatures of 20–150 °C in order to modify their Structure and mechanical behaviour. Some features of obtained HPT-processed samples were compared with initial state with the help of x-ray diffraction (XRD), transmission electron microscopy (TEM) and nanohardness testing. Analysis of structural data and mechanical behaviour allowed us to assume that severe plastic deformation (SPD) processing of melt-spun Ti 50 Ni 25 Cu 25 alloy might lead to the formation of the Structure similar to the new kind of noncrystalline state – “nanoglass” state.
