Crystal Plasticity Research Articles

Tailoring of Selective Chemo-Responsiveness in Liquid Crystals via Organic Ionic Plastic Crystals.

Liquid crystals (LCs) are widely used as promising stimuli-responsive materials due to their unique combination of liquid and crystalline properties, providing the capability to sense even molecular-scale events and amplify them into macroscopic optical outputs. However, encoding a high level of selectivityto a specific intermolecular event remains a key challenge, leading to prior studies regarding chemically functionalized LC interfaces. Herein, we propose an integrative strategy to significantly advance the design of chemo-responsive LCs through a deep fundamental understanding on the orientational coupling of LCs with new functional molecules, organic ionic plastic crystals (OIs), presented at LC interfaces. In combination with computational simulations and experimental validations, we reveal the correlative interplay between LCs and each functional group in OI (di-cationic headgroup, aliphatic tails, and counter anions) to offer an excellent degree of freedom in tailoring the chemo-responsive features in LCs. Especially, we find the crystalline nature of OIs to providenew insights into the effects of counter anions, generating distinct quadrupolar interactions with adjacent molecules. Overall, our results provide generalizable design principles for the chemo-responsive materials that can explicitly distinguish the specific intermolecular event such as molecular bindings of OIs with acetic acid from those with propionic acid (one carbon difference).

A Crystal Plasticity FEM Investigation of Texture Distribution and Plastic Deformation in Commercial Pure Aluminum after Asymmetric Rolling

A Crystal Plasticity FEM Investigation of Texture Distribution and Plastic Deformation in Commercial Pure Aluminum after Asymmetric Rolling

In Situ EBSD Observation and Numerical Simulation of Microstructure Evolution and Strain Localization of DP780 Dual-Phase Steel.

To reveal the microstructural evolution and stress-strain distribution of 780 MPa-grade ferrite/martensite dual-phase steel during a uniaxial tensile deformation process, the plastic deformation behavior under uniaxial tension was studied using in situ EBSD and crystal plastic finite element method (CPFEM). The results showed that the geometrically necessary dislocations (GND) in ferrite accumulated continuously, which is conducive to the formation of grain boundaries, but the texture distribution did not change significantly. The average misorientation angle decreased and the proportion of low-angle grain boundaries increased with the increase of strain. At high strain, the plastic deformation mainly occurred in the soft ferrite region within a 45° distribution from the loading direction. In the undeformed state, the texture of the dual-phase steel was characterized by α-fibers and γ-fibers. Interfacial debonding was caused by the accumulation of geometrically necessary dislocations. The fracture morphologies showed that the specimens had typical ductile fracture characteristics.

Rapid Na+ Transport Pathway and Stable Interface Design Enabling Ultralong Life Solid‐State Sodium Metal Batteries

AbstractSodium‐metal batteries (SMBs) using solid‐state polymer electrolytes (SPEs) show impressive superiority in energy density and safety. As promising candidates for SPEs, solid‐state plastic crystal electrolytes (SPCE) based on succinonitrile (SN) plastic crystal could achieve high ion conductivity and wide voltage window. Nonetheless, the notorious SN decomposition reaction on the electrode/electrolyte interface seriously challenges the stable operation of the battery. To address this drawback, we commence with the structural engineering of the polymer chain segments in SPCE and employ intermolecular interactions to optimize the composition of solid electrolyte interface (SEI). Moreover, this study emphasizes the importance of polymer network design in optimizing the migration behavior of sodium ions in SPCE. The assembled sodium symmetric cells display a high critical current density of up to 2.7 mA cm−2 and stable cycling performance for 700 hours at 0.5 mA cm−2. Furthermore, the Na/SPCE‐9/Na3V2(PO4)3 maintains a discharge specific capacity of up to 76.8 mAh g−1 at 10 C and shows impressive long‐cycle stability, retaining 86.2 % of initial capacity over 5000 cycles with an average coulombic efficiency of 99.9 %. Our work presents a high‐performance SPCE with intrinsic safety, providing valuable insights for the future design of solid‐state SMBs.

Rapid Na+ Transport Pathway and Stable Interface Design Enabling Ultralong Life Solid-State Sodium Metal Batteries.

Sodium-metal batteries (SMBs) using solid-state polymer electrolytes (SPEs) show impressive superiority in energy density and safety. As promising candidates for SPEs, solid-state plastic crystal electrolytes (SPCE) based on succinonitrile (SN) plastic crystal could achieve high ion conductivity and wide voltage window. Nonetheless, the notorious SN decomposition reaction on the electrode/electrolyte interface seriously challenges the stable operation of the battery. To address this drawback, we commence with the structural engineering of the polymer chain segments in SPCE and employ intermolecular interactions to optimize the composition of solid electrolyte interface (SEI). Moreover, this study emphasizes the importance of polymer network design in optimizing the migration behavior of sodium ions in SPCE. The assembled sodium symmetric cells display a high critical current density of up to 2.7 mA cm-2 and stable cycling performance for 700 hours at 0.5 mA cm-2. Furthermore, the Na/SPCE-9/Na3V2(PO4)3 maintains a discharge specific capacity of up to 76.8 mAh g-1 at 10 C and shows impressive long-cycle stability, retaining 86.2 % of initial capacity over 5000 cycles with an average coulombic efficiency of 99.9 %. Our work presents a high-performance SPCE with intrinsic safety, providing valuable insights for the future design of solid-state SMBs.

Study of the boundary migration of recrystallized grains under inhomogeneous deformation field by crystal plasticity – phase field simulation

ABSTRACT In this study, a grain boundary (GB) migration model based on crystal plasticity (CP) and phase field (PF) was constructed for recrystallization of magnesium alloys. The model introduced the stored energy field obtained by CP into the PF simulations, aiming to analyze the effect of the inhomogeneous stored energy generated under the plastic deformation on the GB migration. It was found that the curvature plays a more significant role in the inhomogeneous stored energy field than in the uniform deformation field. Although grains with hard orientation have a lower deformation storage energy, they are still partially swallowed due to mutual influence between GBs near the triple junction. The high energies in the original GBs increase the migration rate at the triple junctions locally for a short period of time, but it is not enough to make a significant difference over extended periods at mesoscopic scales. The simulation results in this study are helpful in explaining the previous experimental observations.

Unlocking Sulfide Solid-State Battery Longevity by the Paradigm of Dual-Functional Plastic Crystal.

The utilization of sulfide-based solid electrolytes represents an attractive avenue for high safety and energy density all-solid-state batteries. However, the potential has been impeded by electrochemical and mechanical stability at the interface of oxide cathodes. Plastic crystals, a class of organic materials exhibiting remarkable elasticity, chemical stability, and ionic conductivity, have previously been underutilized due to their susceptibility to dissolution in liquid electrolytes. Nevertheless, their application in all-solid-state batteries presents a paradigm that could potentially overcome longstanding interface-related obstacles. This study presents a facile approach to enhancing the performance of sulfide-based solid-state batteries by utilizing nickel-rich oxide cathodes coated with ionically conductive plastic crystals. For employing plastically deformed succinonitrile as a metal ion ligand, it simultaneously supports mechanical stability and interfacial conduction, while LiDFOB establishes moderate ionic conductivity and a stable cathode electrolyte interphase (CEI). The synergistic effects of these mechanisms culminate in remarkable long-term performance metrics, with the capacity retaining 80% after 1529 cycles. Furthermore, this stability is maintained even when the areal capacity density is increased to a substantial 3.53 mA h cm-2. By combining electrochemical stability with mechanical plasticity, this approach opens possibilities for the development of long-lasting solid-state batteries suitable for practical applications.

Organic ionic plastic crystals having colossal barocaloric effects for sustainable refrigeration

Organic ionic plastic crystals having colossal barocaloric effects for sustainable refrigeration

Interference of multi-pore collapse in explosive crystal under shock loading

Hotspots are generally recognized as the cause of ignition of heterogeneous explosives under shock loading, and the pores in the explosive crystal are the primary hotspots contributing to localized temperature rise and ignition. To investigate the interaction mechanism between pores in explosive crystals, the discrete element method is employed to numerically simulate the collapse processes of pores with various arrangements in explosive crystals under shock loading. The influence of the viscosity and plasticity of the explosive crystal on temperature rise is considered in the simulation. The results revealed that the interaction among the pores is essentially the interference of the upstream pore collapse on the shock wave front, which subsequently loads on the downstream pores and reflects back to the upstream pores. The perturbed shock wave loads on the downstream pores in various patterns due to the diversity in pore distance, size, and arrangement orientation, leading to different interference patterns. The causes of each interference pattern and its influence on localized temperature rise are further analyzed. Finally, the collapse patterns of downstream pores discovered in the simulation are summarized, identifying the six most representative downstream pore collapse patterns.

Precipitation-controlled grain boundary engineering in a cast & wrought Ni-based superalloy

Grain boundary engineering (GBE) describes the various approaches to control the fraction and composition of special boundaries in designing engineering materials. For example, complex thermo-mechanical processing routes are harnessed to increase the fraction of Σ3 twin boundaries, bringing about improvements to strength, toughness, and corrosion properties in austenitic stainless steels. However, high-temperature gas turbine engine components designed for the most demanding applications must be manufactured from Ni-based superalloys. To provide the required high-temperature strength, their microstructures are highly complex and consist of an austenitic γ-matrix, γ' precipitates, and grain boundary (GB) carbides, and/or borides. GBE approaches for Ni-based superalloys have been reported to reduce in-service GB cracking via targeted engineering of the GB microstructure. However, the same complex microstructures severely limit the processability of the most advanced Ni-based superalloys required to develop the next generation gas turbine engines.To tackle this challenge, we propose precipitation-controlled GBE for Ni-based superalloys with limited formability, via formation of GB serrations and precipitation upon slow cooling. We showcase our approach by achieving controlled GB precipitation of GB-γ' and M6C carbides in the cast & wrought Ni-based superalloy René 41 via a simple heat treatment. Ductility improvements are predicted via crystal plasticity modeling due to increased slip transmission compatibility. Instead of generating additional Σ3 twin boundaries only, these interfaces are directly incorporated into the GB network. It is shown that precipitation-controlled GBE is enabled by GB-γ' nucleating heterogeneously on M6C whereby competitive coarsening of GB-γ' provides the driving force. The fundamental mechanisms of our GBE approach are discussed and summarized in a qualitative microstructural model.

Mechanical responses and microstructure evolution of DP780 in complete σxx-σyy space: experiments and crystal plasticity characterization

Mechanical responses and microstructure evolution of DP780 in complete σxx-σyy space: experiments and crystal plasticity characterization

Models for plastic flow: people, places, concepts and techniques

Fred Kocks’ professional life spanned a period of intense development in the understanding of the micromechanics of plastic flow. Continuum plasticity theory and the concepts of crystal plasticity with defined slip planes and directions were well established in 1959 when Fred graduated from the University of Göttingen. The concept of dislocations, discrete carriers of deformation, and their interactions, had initiated a wave of activity across Europe and the US, offering the potential for micro-mechanical models for plastic flow and its dependence on composition, temperature, time (strain-rate) and prior mechanical history. Fred became one of the principal players in the field, starting with his 1958 study of the deformation of polycrystals [1]. To understand his approach and his subsequent contributions it helps to have a picture of the intellectual climate of Göttingen and the excitement of generated by dislocation-plasticity at that time. This brief paper describes this context in which Fred’s work should be viewed.

Deformation mechanisms in pure Mg single crystal under erichsen test: Experimental observations and crystal plasticity predictions

Deformation mechanisms in pure Mg single crystal under erichsen test: Experimental observations and crystal plasticity predictions

Grain refinement and its effect of polycrystalline metals during high strain rate deformation: Crystal plasticity modeling

Grain refinement and its effect of polycrystalline metals during high strain rate deformation: Crystal plasticity modeling

Evaluation of small fatigue crack deflection behavior on copper using electron backscatter diffraction and crystal plasticity finite element analysis

Evaluation of small fatigue crack deflection behavior on copper using electron backscatter diffraction and crystal plasticity finite element analysis

Atomistic-Informed and Machine Learning–Assisted Crystal Plasticity Modeling for Material Interfaces

Atomistic-Informed and Machine Learning–Assisted Crystal Plasticity Modeling for Material Interfaces

Quantitative comparison between experiments and crystal plasticity simulations using microstructural clones

Quantitative comparison between experiments and crystal plasticity simulations using microstructural clones

Micromechanical analysis of spherulitic polymers in multiaxial and non-proportional fatigue crack nucleation

This study focused on understanding the fatigue response of anisotropic spherulitic polymers by employing a multiscale microscopic modeling approach. The crystal plasticity model together with the Arruda-Boyce model were used to describe the mechanical response of crystalline phase and amorphous. The fatigue behaviors and crack initiation were captured by Fatemi-Socie multiaxial criterion and continuous damage theory under multiaxial and non-proportional loading conditions. The sheaf-like structure of spherulitic polymers was considered to shed light on the anisotropic nature of fatigue failure. The results highlight the role of features of sheaf structure, e.g., initiation orientation, on the fatigue performance of spherulitic polymers, which have not been reported. The localized degradation of mechanical properties and the accumulation of fatigue damage were systematically discussed with various loading patterns. This study provided an in-depth understanding of potential fatigue mechanisms, offering robust support for fatigue resistance design in engineering applications.

Crystal Plasticity Simulation of Cyclic Behaviors of AZ31B Magnesium Alloys via a Modified Dislocation-Twinning-Detwinning Model.

In this study, a probabilistic model within the dislotwin constitutive framework of DAMASK (the Düsseldorf Advanced Material Simulation Kit) was established to describe the cyclic loading behaviors of AZ31B magnesium alloys. Considering the detwinning procedure within the twinned region, this newly developed dislocation-twinning-detwinning model was employed to accurately simulate stress-strain behaviors of AZ31B magnesium alloys throughout tension-compression-tension (T-C-T) cycle loading. The investigations revealed that the reduction in yield stress during the reverse loading process was attributed to the active operation of twinning and detwinning modes. Furthermore, the evolution of the twin volume fraction during cycle loading scenarios was quantitatively determined. According to these results, the relative activities of plastic deformation modes during T-C-T loading were further analyzed.

Review on multi-scale mechanics fundamentals and numerical methods for electronics packaging interconnect materials

This paper examines multiscale theories and numerical methods for interconnect materials in electronic packaging, focusing on the interplay among micro-scale morphology, meso-scale structure, and macro-scale behavior to improve material reliability and performance prediction. It reviews advanced materials, such as sintered silver and lead-free solder, alongside methodologies like Molecular Dynamics (MD) simulations, cohesive modeling, crystal plasticity modeling, and phase-field modeling, to evaluate mechanical and thermal properties across scales and their long-term reliability. At the microscopic scale, MD simulations reveal the influence of atomic arrangements, grain orientations, and dislocation evolution on mechanical behavior. At the mesoscopic scale, phase-field and crystal plasticity models are combined to analyze pore evolution, grain sliding, and stress concentration under thermal cycling. Macroscopically, models like Anand and Unified Creep Plasticity (UCP) describe viscoplasticity, creep, and fatigue life, offering insights into performance under complex conditions. By systematically integrating diverse research methods and theoretical models, this review highlights the applicability of a multiscale coupling framework, providing a comprehensive understanding of the correlations between morphology, structure, and behavior. This framework serves as theoretical guidance for developing innovative packaging solutions and optimizing materials for high-density, low-power electronic devices.