Latest Articles of Acta Materialia


Compositional effect on microstructure and properties of NbTiZr-based complex concentrated alloys 10.1016/j.actamat.2018.03.065 2018-04-04 Phase composition, microstructure and mechanical properties of six complex concentrated alloys, NbTiZr, NbTiZrV, NbTiZrVMo, NbTiZrVTa, NbTiZrVCr, and NbTiZrVAl0.24, are reported. The alloy density was in the range from 6.34 g/cm3 to 8.43 g/cm3. After homogeni...
High resolution transmission electron microscopy correlated to in-field Mössbauer spectrometry to investigate exchange coupling behavior and surface frustrated moments 10.1016/j.actamat.2018.03.066 2018-04-04 In this work, we present a correlation between High Resolution Transmission Electron Microscopy (HRTEM) and in-field Mössbauer spectrometry to point out exchange coupling behavior, surface effects and chemical disorder in CoxFe3-xO4 cobalt ferrite nanoparticl...
Effect of heat treatment on the microstructural evolution of a nickel-based superalloy additive-manufactured by laser powder bed fusion 10.1016/j.actamat.2018.03.017 2018-04-04 Elemental segregation is a ubiquitous phenomenon in additive-manufactured (AM) parts due to solute rejection and redistribution during the solidification process. Using electron microscopy, in situ synchrotron X-ray scattering and diffraction, and thermodynam...
Fatigue deformation in a polycrystalline nickel base superalloy at intermediate and high temperature: Competing failure modes 10.1016/j.actamat.2018.03.035 2018-04-03 The microstructural configurations that favor early strain localization and fatigue crack initiation at intermediate and high temperature (400 °C–650 °C) have been investigated using novel experimental techniques, including high resolution digital image corre...
Deformation mechanisms of nil temperature ductile polycrystalline B2 intermetallic compound YAg 10.1016/j.actamat.2018.03.064 2018-04-02 The most ductile rare earth intermetallic compound, YAg, was subjected to an thermal activation analysis at low temperatures down to 4 K. Evaluation of the activation parameters and their dependence on stress and temperature yields strong indication for fores...
Grain boundary properties of a nickel-based superalloy: Characterisation and modelling 10.1016/j.actamat.2018.03.059 2018-04-02 Miniaturised tensile tests coupled with in-situ scanning electron microscopy are used to deduce the grain boundary properties of a nickel-based superalloy at 750 °C. This allows the damage initiation, evolution and failure processes to be observed directly. T...
Grain boundary complexions and the strength of nanocrystalline metals: Dislocation emission and propagation 10.1016/j.actamat.2018.03.055 2018-04-02 Grain boundary complexions have been observed to affect the mechanical behavior of nanocrystalline metals, improving both strength and ductility. While an explanation for the improved ductility exists, the observed effect on strength remains unexplained. In t...
Experimental and DFT characterization of interphase boundaries in titanium and the implications for ω-assisted α phase precipitation 10.1016/j.actamat.2018.03.056 2018-04-02 An intricate understanding of the fundamental β→α phase transformation upon the presence of metastable ω phase is vital for tailoring the multiphase microstructures of titanium and titanium alloys for various specific applications. To approach this, the struc...
Adiabatic shear localization in the CrMnFeCoNi high-entropy alloy 10.1016/j.actamat.2018.03.040 2018-04-02 The mechanical behavior of the single phase (fcc) CrMnFeCoNi high-entropy alloy (HEA) is examined in the dynamic regime. A series of experiments by dynamic-loading hat-shaped specimens using stopper rings to control the displacement are performed, and the all...
γ+γ′ microstructures in the Co-Ta-V and Co-Nb-V ternary systems 10.1016/j.actamat.2018.03.057 2018-04-02 The Co-Ta-V and Co-Nb-V ternary systems are investigated in a search for L12-ordered γ′ precipitation, based on recent computational predictions of stable γ+γ′ microstructures. Four alloys with nominal (at. %) composition Co-6Ta-6V, Co-5.4Ta-6.6V-xNi (x = 0 a...

Compositional effect on microstructure and properties of NbTiZr-based complex concentrated alloys

10.1016/j.actamat.2018.03.065

2018-04-04

Phase composition, microstructure and mechanical properties of six complex concentrated alloys, NbTiZr, NbTiZrV, NbTiZrVMo, NbTiZrVTa, NbTiZrVCr, and NbTiZrVAl0.24, are reported. The alloy density was in the range from 6.34 g/cm3 to 8.43 g/cm3. After homogeni...

High resolution transmission electron microscopy correlated to in-field Mössbauer spectrometry to investigate exchange coupling behavior and surface frustrated moments

10.1016/j.actamat.2018.03.066

2018-04-04

In this work, we present a correlation between High Resolution Transmission Electron Microscopy (HRTEM) and in-field Mössbauer spectrometry to point out exchange coupling behavior, surface effects and chemical disorder in CoxFe3-xO4 cobalt ferrite nanoparticl...

Effect of heat treatment on the microstructural evolution of a nickel-based superalloy additive-manufactured by laser powder bed fusion

10.1016/j.actamat.2018.03.017

2018-04-04

Elemental segregation is a ubiquitous phenomenon in additive-manufactured (AM) parts due to solute rejection and redistribution during the solidification process. Using electron microscopy, in situ synchrotron X-ray scattering and diffraction, and thermodynam...

Fatigue deformation in a polycrystalline nickel base superalloy at intermediate and high temperature: Competing failure modes

10.1016/j.actamat.2018.03.035

2018-04-03

The microstructural configurations that favor early strain localization and fatigue crack initiation at intermediate and high temperature (400 °C–650 °C) have been investigated using novel experimental techniques, including high resolution digital image corre...

Deformation mechanisms of nil temperature ductile polycrystalline B2 intermetallic compound YAg

10.1016/j.actamat.2018.03.064

2018-04-02

The most ductile rare earth intermetallic compound, YAg, was subjected to an thermal activation analysis at low temperatures down to 4 K. Evaluation of the activation parameters and their dependence on stress and temperature yields strong indication for fores...

Grain boundary properties of a nickel-based superalloy: Characterisation and modelling

10.1016/j.actamat.2018.03.059

2018-04-02

Miniaturised tensile tests coupled with in-situ scanning electron microscopy are used to deduce the grain boundary properties of a nickel-based superalloy at 750 °C. This allows the damage initiation, evolution and failure processes to be observed directly. T...

Grain boundary complexions and the strength of nanocrystalline metals: Dislocation emission and propagation

10.1016/j.actamat.2018.03.055

2018-04-02

Grain boundary complexions have been observed to affect the mechanical behavior of nanocrystalline metals, improving both strength and ductility. While an explanation for the improved ductility exists, the observed effect on strength remains unexplained. In t...

Experimental and DFT characterization of interphase boundaries in titanium and the implications for ω-assisted α phase precipitation

10.1016/j.actamat.2018.03.056

2018-04-02

An intricate understanding of the fundamental β→α phase transformation upon the presence of metastable ω phase is vital for tailoring the multiphase microstructures of titanium and titanium alloys for various specific applications. To approach this, the struc...

Adiabatic shear localization in the CrMnFeCoNi high-entropy alloy

10.1016/j.actamat.2018.03.040

2018-04-02

The mechanical behavior of the single phase (fcc) CrMnFeCoNi high-entropy alloy (HEA) is examined in the dynamic regime. A series of experiments by dynamic-loading hat-shaped specimens using stopper rings to control the displacement are performed, and the all...

γ+γ′ microstructures in the Co-Ta-V and Co-Nb-V ternary systems

10.1016/j.actamat.2018.03.057

2018-04-02

The Co-Ta-V and Co-Nb-V ternary systems are investigated in a search for L12-ordered γ′ precipitation, based on recent computational predictions of stable γ+γ′ microstructures. Four alloys with nominal (at. %) composition Co-6Ta-6V, Co-5.4Ta-6.6V-xNi (x = 0 a...