Grain boundary relaxation

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Webrelaxation was recently found to be effective in stabilizing nanograined pure metals. Grain boundary relaxation can be induced by deforming very fine nanograins below a critical … WebMar 24, 2024 · We aimed to tailor GB stability by means of GB relaxation and segregation in nanograined nickel-molybdenum (Ni–Mo) alloys with extremely fine grains in which the GB effect is greatly amplified. We present evidence that the plastic deformation and hardness of the nanograined metals are essentially governed by GB stability.

Assessment of Strain Relaxation and Oxygen Vacancy Migration …

WebMar 14, 2012 · Grain boundary relaxation removes excess grain boundary dislocations, reducing the density of sources available for dislocation emission. Fewer available … Webfavor GB sliding and grain rotation, which are collective processes that could be expected to be more effective at relaxing non-equilibrium GB structures. Atomistic details of the … ctp frc

Grain boundary relaxation behavior and phase stability of AlCrTiVx (x ...

WebApr 13, 2024 · The paper studies the mechanisms of plastic relaxation and mechanical response depending on the concentration of Cu atoms at grain boundaries (GBs) in nanocrystalline aluminum with molecular dynamics simulations. A nonmonotonic dependence of the critical resolved shear stress on the Cu content at GBs is shown. WebIn the conventional treatments of grain boundary phonon scattering, the Casimir limit is commonly used (τ b = L / v s, where τ b is the phonon relaxation time associated with … WebApr 5, 2024 · [44, 48] Based on this model, the relaxation could occur by the flow of matter along the grain boundaries which may cause the local thickening/thinning of the grains in the constrained film [44, 46] (Figure 8e), undeformed lattice planes and deformed grain boundaries). Therefore, the Coble creep model is used for the quantification of the creep ... ctp frontid

Grain boundary relaxation strengthening of nanocrystalline

Assessment of Strain Relaxation and Oxygen Vacancy Migration near Grain ...

WebAug 14, 2024 · Under the applied ac electric field, the migration of charge carriers within the ZnO ceramic can be restricted by two high-resistance barriers from grain boundaries and intergranular phases. These barriers result in two dispersion processes in conductivity response, which exhibit two relaxation peaks with activation energies of 0.75 eV and … WebApr 28, 2004 · Grain Boundary Relaxation and the Mechanism of Embrittlement of Copper by Bismuth: Journal of Applied Physics: Vol 20, No 12. No Access Submitted: 01 July … earthsoft websiteWebApr 11, 2024 · Watanabe, “An approach to grain boundary design for strong and ductile polycrystals,” Res. Mech. 11(1), 47–84 (1984). GB engineering is proposed to deliberately manipulate the GB structure in order to improve material properties such as corrosion resistance, intergranular cracking, or ductility. 26 26. T. ctpf retiree

"WebFeb 3, 2024 · Figure 6. Grain-boundary sliding as a viscoelastic relaxation mechanism. The low effective viscosity of the grain-boundary region facilitates local shear stress … " - Grain boundary relaxation

Grain boundary relaxation

Thermomechanical and Creep Behaviors of Multilayered …

WebApr 20, 2006 · Grain-boundary relaxation in nanocrystalline Fe was studied by high-resolution transmission electron microscopy (HREM), and its effect on plasticity was characterized by nanoindentation. … WebThe embrittlement of copper by small amounts of bismuth has been known for many years. Voce and Hallowes proposed recently that the agent responsible for embrittlement is bismuth present in the form of thin films at copper grain boundaries. In order to examine this picture from a different angle, internal friction and elastic modulus measurements …

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WebJan 31, 2003 · It is found that when grain boundaries are formed between two crystals a considerable variety of modes of relaxations, i.e., the rearrangements of atoms in and near the grain boundary core are possible, depending on grain boundary geometry and the interatomic interactions. WebMar 8, 2016 · The internal friction peak induced by grain boundary (GB) relaxation was discovered by Kê in polycrystals in 1947. The GB internal friction and related anelastic effects have been...

WebThus, any relaxation peak is likely to be directly relat- ed to grain-boundary sliding without being overlapped by transgranular phenomena of diffusive or other origin. 2. … WebNov 30, 2024 · Grain boundary (GB) diffusion and viscous flow play dominant roles in mechanical relaxation of polycrystalline materials. The pioneering work of Zener and Kê, …

WebGB peak). It was suggested that twin boundaries and grain boundaries across the transversal section of the specimen were necessary for the occurrence of the FTP and the HTP, respectively. 2.2 Relaxation strength and activation enthalpy versus stacking fault energy A suggestive correlation between relaxation parameters (relaxation strength and ... WebOct 23, 2024 · The role of grain boundary scattering in reducing the thermal conductivity of polycrystalline XNiSn (X = Hf, Zr, Ti) half-Heusler alloys Scientific Reports Open Access 23 October 2024 The...

WebJun 10, 2024 · The role of GBS during relaxation is studied using the deformation induced evolution of surface inhomogeneity. Determinations of surface profiling step heights at grain boundaries and inclination of grains were used to quantify the effect of GBS. The estimated activation volume of 4.35 b^3 further confirms the role of slip induced GBS on the ...

WebMar 1, 2024 · Grain boundary relaxation can be induced by deforming very fine nanograins below a critical size, typically several tens of nanometers. Here, we found that rapid heating may trigger intensive ... ctpf senior manager complianceWebApr 24, 2024 · Grain boundary relaxation can be induced by deforming very fine nanograins below a critical size, typically several tens of nanometers. Here, we found … earthsoft office hoursWebWith the grain boundary acting as a barrier to the oxygen vacancy migration, there can be a strain gradient on both sides of the grain boundary, and also with the charge an internal electrical field is developed. ctpga foundationWebJul 1, 2024 · (a) Schwarzation: Schwarz crystal with a grain size of about 5 nm; (b) and (c) GB relaxation in 40 nm grains with through-grain stacking faults and twins and a relaxed grain boundary showing facet ... ctp frtbWebMay 30, 2024 · Three series of experiments are presented in this work, where relaxation maxima were detected related to the behavior of impurity atoms inside the grains and at the grain boundaries: grain boundary maxima. Internal Friction of Specimens Oxidized in Air earth soil dirtWeb1 day ago · Grain boundary cavity formation is profuse in nanocrystalline materials due to their intrinsically high interfacial sink density [11], ... Finally, an additional relaxation step was performed for 1 ns at 27°C again using the isothermal-isobaric ensemble to achieve a zero-pressure condition along all directions. ctpf survivor benefitsWebthrough a process termed “grain boundary relaxation,” whichis alow-temperatureprocess thatcanoccur without any measurable change in grain size or … earth soil components