The Experts below are selected from a list of 207 Experts worldwide ranked by ideXlab platform
D Han - One of the best experts on this subject based on the ideXlab platform.
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improving the stress controlled fatigue life of low Solid Solution Hardening ni cr alloys by enhancing short range ordering degree
International Journal of Fatigue, 2021Co-Authors: Y J Zhang, D HanAbstract:Abstract The tension-tension fatigue behavior of low Solid-Solution Hardening Ni-Cr alloys with an approximately constant stacking fault energy was systematically investigated under different stress amplitudes. With an enhancement of short range ordering (SRO) degree, the fatigue crack initiation mode is evolved from intergranular cracking to slip band cracking, and the cyclic deformation mechanism changes from wavy to planar dislocation slip. Both the fatigue strength coefficient (σ'f) and exponent (b) can be simultaneously increased by inducing SRO structure that greatly enhances the cyclic strain Hardening capacity, deformation homogeneity and slip reversibility, and the fatigue life is thus significantly improved.
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impact of short range ordering on the anomalous four stage strain Hardening behavior of low Solid Solution Hardening ni cr alloys
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2021Co-Authors: Y J Zhang, D HanAbstract:Abstract The effect of short range ordering (SRO) on the strain Hardening behavior of low Solid-Solution Hardening Ni-Cr alloys with high stacking fault energies (SFEs) was systematically investigated under uniaxial compression to a high true strain et of 0.9 at room temperature. An unexpected four-stage (including Stages A, B, C and D) changing law in strain Hardening rate was revealed, which is completely different from the case of conventional high-SFE alloys whose strain Hardening rate just monotonously declines as the strain increases. Observations on the deformation microstructures strongly demonstrate that the recovery of strain Hardening rate in Ni-Cr alloys (Cr ≥ 20 at.%) at Stages B (0.11
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A unique two-stage strength-ductility match in low Solid-Solution Hardening Ni-Cr alloys: Decisive role of short range ordering
Scripta Materialia, 2020Co-Authors: Y J Zhang, D HanAbstract:Abstract The effect of short range ordering (SRO) on the strength-ductility match of low Solid-Solution Hardening Ni-Cr alloys with high stacking fault energies (SFEs) were systematically investigated under tensile tests. With increasing Cr content, the SFE and friction stress keep almost unchanged but the SRO degree becomes enhanced; in this case, the deformation mechanism was evolved from wavy slip to planar slip, and deformation twinning was further induced as the Cr content exceeds 20 at.%, which leads to a unique two-stage strength-ductility match of Ni-Cr alloys. The action of SRO has merely played a decisive role for such an experimental phenomenon.
Y J Zhang - One of the best experts on this subject based on the ideXlab platform.
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improving the stress controlled fatigue life of low Solid Solution Hardening ni cr alloys by enhancing short range ordering degree
International Journal of Fatigue, 2021Co-Authors: Y J Zhang, D HanAbstract:Abstract The tension-tension fatigue behavior of low Solid-Solution Hardening Ni-Cr alloys with an approximately constant stacking fault energy was systematically investigated under different stress amplitudes. With an enhancement of short range ordering (SRO) degree, the fatigue crack initiation mode is evolved from intergranular cracking to slip band cracking, and the cyclic deformation mechanism changes from wavy to planar dislocation slip. Both the fatigue strength coefficient (σ'f) and exponent (b) can be simultaneously increased by inducing SRO structure that greatly enhances the cyclic strain Hardening capacity, deformation homogeneity and slip reversibility, and the fatigue life is thus significantly improved.
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impact of short range ordering on the anomalous four stage strain Hardening behavior of low Solid Solution Hardening ni cr alloys
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2021Co-Authors: Y J Zhang, D HanAbstract:Abstract The effect of short range ordering (SRO) on the strain Hardening behavior of low Solid-Solution Hardening Ni-Cr alloys with high stacking fault energies (SFEs) was systematically investigated under uniaxial compression to a high true strain et of 0.9 at room temperature. An unexpected four-stage (including Stages A, B, C and D) changing law in strain Hardening rate was revealed, which is completely different from the case of conventional high-SFE alloys whose strain Hardening rate just monotonously declines as the strain increases. Observations on the deformation microstructures strongly demonstrate that the recovery of strain Hardening rate in Ni-Cr alloys (Cr ≥ 20 at.%) at Stages B (0.11
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A unique two-stage strength-ductility match in low Solid-Solution Hardening Ni-Cr alloys: Decisive role of short range ordering
Scripta Materialia, 2020Co-Authors: Y J Zhang, D HanAbstract:Abstract The effect of short range ordering (SRO) on the strength-ductility match of low Solid-Solution Hardening Ni-Cr alloys with high stacking fault energies (SFEs) were systematically investigated under tensile tests. With increasing Cr content, the SFE and friction stress keep almost unchanged but the SRO degree becomes enhanced; in this case, the deformation mechanism was evolved from wavy slip to planar slip, and deformation twinning was further induced as the Cr content exceeds 20 at.%, which leads to a unique two-stage strength-ductility match of Ni-Cr alloys. The action of SRO has merely played a decisive role for such an experimental phenomenon.
Isaac Todacaraballo - One of the best experts on this subject based on the ideXlab platform.
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computational design of light and strong high entropy alloys hea obtainment of an extremely high specific Solid Solution Hardening
Scripta Materialia, 2018Co-Authors: Edern Menou, Franck Tancret, Isaac Todacaraballo, Gerard Ramstein, Nicolas Gautier, Emmanuel Bertrand, P. Castany, Pedro Eduardo Jose Rivera DiazdelcastilloAbstract:A multi-objective optimisation genetic algorithm combining Solid Solution Hardening (SSH) and thermodynamic modelling (CALPHAD) with data mining is used to design high entropy alloys (HEAs). The approach searches for the best compromise between single-phase stability, SSH and density. Thousands of Pareto-optimal base-centred cubic (BCC) HEAs are designed. Al35Cr35Mn8Mo5Ti17 (at.%) is chosen for experimental validation. The alloy was cast and characterised. Its microstructure consists of large grains of a single disordered Solid Solution displaying a Vickers hardness of 6.45 GPa (658 HV) and a density below 5.5 g/cm3; uniquely combining exceptional hardness with medium density. © 2018 Acta Materialia Inc
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a general formulation for Solid Solution Hardening effect in multicomponent alloys
Scripta Materialia, 2017Co-Authors: Isaac TodacaraballoAbstract:Abstract This paper presents a general formulation for the effect of the Solid Solution Hardening (SSH) in multicomponent alloys. It bridges the existing approaches analyzing this Hardening effect between binary alloys and highly concentrated multicomponent systems. The model is validated with a comprehensive dataset of measured critical resolved shear stress, hardness and yield strength of binary and multicomponent systems from the literature.
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modelling Solid Solution Hardening in high entropy alloys
Acta Materialia, 2015Co-Authors: Isaac Todacaraballo, P E J RiveradiazdelcastilloAbstract:Abstract Solid Solution Hardening (SSH) is one of the major contributions to the excellent mechanical properties displayed by high entropy alloys (HEAs). SSH is first analysed for binary systems in face-centred cubic and body-centred cubic alloys with different elemental additions in the temperature range 5–623 K. The prediction of the SSH has been possible by using Labush’s approach for SSH modelling, where the necessary parameters have been incorporated without fitting to experimental data. Among these parameters, elastic misfit is shown to be prominent; experimental evidence suggests it has a dominant effect with respect to other misfit forms. Nevertheless, Labush’s approach cannot be directly applied to model SSH in HEAs, since it is based on the misfit produced in the lattice of a solvent/reference atom, which does not exist in HEAs. Its extension to HEAs has been performed by using Mooren’s approach for the computation of interatomic spacing in multicomponent alloys, allowing the creation of a model for elastic misfit in HEAs. This has led to a methodology for computing SSH effect in HEAs, where the results have successfully been compared with a collection of experimental data from the literature. The explanation of how different atoms can modify the yield strength can be formulated in terms of this approach.
Rolf Sandström - One of the best experts on this subject based on the ideXlab platform.
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first principles evaluation of the effect of alloying elements on the lattice parameter of a 23cr25niwcuco austenitic stainless steel to model Solid Solution Hardening contribution to the creep strength
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2015Co-Authors: Pavel A Korzhavyi, Rolf SandströmAbstract:Abstract By the use of first-principles calculations based on density functional theory, lattice misfit parameters for alloying elements in the austenitic stainless steel 23Cr25NiWCuCo have been derived. These lattice misfit parameters have been applied to determine the Solid Solution Hardening of the elements W, Nb, and Cu in the steel. The model for Solid Solution Hardening is based on work by Hirth and Lothe, where solutes are creating Cottrell clouds around the dislocations and slow down their motion. The model is also verified by comparison to creep tests for Ni–20%Cr and Ni–20%Cr–6W, where W is almost completely in Solid Solution and no other strengthening mechanism than Solid Solution Hardening should be active. The contribution from the interstitial elements C and N to the Solid Solution Hardening is found to be negligibly small for the studied steel.
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Modelling Solid Solution Hardening in stainless steels
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005Co-Authors: Henrik Sieurin, Johan Zander, Rolf SandströmAbstract:The Solid Solution Hardening of stainless steels is studied by using the Labusch-Nabarro relation. Models are evaluated in order to predict the mechanical properties from chemical composition, solu ...
Szilárd Kolozsvári - One of the best experts on this subject based on the ideXlab platform.
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Solid Solution Hardening of vacancy stabilized tixw1 xb2
Acta Materialia, 2015Co-Authors: Holger Euchner, Paul H. Mayrhofer, Helmut Riedl, F.f. Klimashin, Andreas Limbeck, Peter Polcik, Szilárd KolozsváriAbstract:Abstract We present a combined experimental and theoretical investigation of sputter deposited thin films in the ternary system Ti 1− x W x B 2 . Solid Solutions of Ti 1− x W x B 2− z were prepared by physical vapor deposition (PVD) and, over the whole composition range, found to crystallize in the AlB 2 structure type. The obtained films exhibit good thermal stability and high hardness, evidencing a maximum value of almost 40 GPa for Ti 0.67 W 0.33 B 2− z . The effect of vacancies on stabilization and mechanical properties of the AlB 2 structure type is discussed, using ab initio simulations. Based on our results, we can conclude that vacancies are crucial for the phase stability of PVD deposited Ti 1− x W x B 2− z coatings.
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Solid Solution Hardening of vacancy stabilized TixW1−xB2
Acta Materialia, 2015Co-Authors: Holger Euchner, Paul H. Mayrhofer, Helmut Riedl, F.f. Klimashin, Andreas Limbeck, Peter Polcik, Szilárd KolozsváriAbstract:Abstract We present a combined experimental and theoretical investigation of sputter deposited thin films in the ternary system Ti 1− x W x B 2 . Solid Solutions of Ti 1− x W x B 2− z were prepared by physical vapor deposition (PVD) and, over the whole composition range, found to crystallize in the AlB 2 structure type. The obtained films exhibit good thermal stability and high hardness, evidencing a maximum value of almost 40 GPa for Ti 0.67 W 0.33 B 2− z . The effect of vacancies on stabilization and mechanical properties of the AlB 2 structure type is discussed, using ab initio simulations. Based on our results, we can conclude that vacancies are crucial for the phase stability of PVD deposited Ti 1− x W x B 2− z coatings.
