The accumulation of geometrically necessary dislocations (GND) at grain boundaries is a primary source of long-range internal stress (LRIS) in polycrystals. The distribution of GNDs is typically inhomogeneous, and certain dislocation substructures with concentrated GNDs introduce a strong non-local effect. While many studies have explored the relationship between LRIS and the density of GNDs in polycrystals

The creep behavior of 316L stainless steel at room temperature was evaluated as a function of time and applied stress using a new high-throughput approach. Several common creep models were evaluated against the observations, leading to deeper analysis of a stress-dependent modified logarithmic creep model. Within this model, multiple sources of uncertainty were compared. Aleatoric stochastic variation

A continuum damage mechanics (CDM) creep model was developed based on the microstructure, which could precisely delineate the evolution of mobile dislocations, dipole dislocations, boundary dislocations, and martensitic laths in the RAFM steel during creep process. The addition of Ta/Zr elements promoted the precipitation of MX carbide particles, which could pin the mobile dislocations, and restrain

This study systematically investigates the deformation mechanism and strengthening effects of the CoCrFeNiMn0.75Cu0.25 high-entropy alloy (HEA) under dynamic tensile loading across a wide temperature range (93 K to 1073 K). The HEA exhibits a ∼30% enhancement in strength and ductility at 93 K relative to its performance at 298 K. These superior properties result from the synergistic interactions among

This study investigates size effect in nickel-titanium (NiTi) shape memory alloys (SMAs), focusing on their elastic deformation and phase transformation behaviors. A series of experiments, including bulk-scale tension tests, micro-scale tension, compression, and cantilever bending tests, were conducted to observe the effect of specimen dimensions on SMA behavior. Micro-scale tension and compression

We investigate the heterogeneity of the stress state driven by anisotropic deformation response at the single crystal level through five statistical volume element (SVE) calculations of polycrystalline BCC tantalum. This work focuses on grain boundaries as a prominent material defect type prone to void nucleation based upon experimental observations of predominantly intergranular void nucleation in

The pursuit of alloys that integrate high strength and substantial plasticity persists across various industries. Nevertheless, alloys engineered for elevated strength commonly manifest unsustainable work hardening, ultimately leading to a decline in plasticity. Dual- or even multi-phase systems offer vast potential for novel microstructural engineering aimed at harmonizing these inversely related

This study systematically investigates the effects of different annealing treatments before identical aging on precipitation and mechanical properties of an L12-strengthened Fe-rich medium-entropy alloy (Fe-MEA) fabricated by laser powder bed fusion (L-PBF). These treatments result in distinct final microstructures characterized by either discontinuous precipitation (DP) or continuous precipitation

A study of the partitioning of external power into stress power, stored defect energy, thermal energy, and inertia during dynamic void growth is presented. An alternative form for a classical thick-walled sphere governing equation stemming from a local power balance including energetic cost of free surface creation is proposed. The importance of proper energy accounting in the context of dynamic ductile

Shear banding coupled with grain refinement plays a critical role in fracture behavior under dynamic loading and (very) high-cycle fatigue but is rarely observed during low-strain-rate loading. In this study, we report for the first experimental evidence of shear banding mediated fracture mechanism in an electron beam powder bed fusion (EBPBF) fabricated IN738 superalloy upon low-strain-rate (1 × 10−3

Minimal State Cells (MSCs) have successfully overcome the self-consistency and state space issues of standard RNNs when modeling the large deformation response of solids. However, in case of rate- and temperature-dependent materials, MSC-based stress predictions still suffer from instabilities when refining the input path discretization. To resolve this issue, we develop an extended minimal state cell

The intra-granular γ′ phase and inter-granular M23C6 in a polycrystalline Ni3Al-based superalloy are cooperatively controlled through a two-stage-cooling solution treatment. The rapid cooling stage suppresses the coarsening of the γ′ phase, while the subsequent slow cooling stage promotes the precipitation of M23C6. The co-strengthening of intra- and inter-granular particles leads to a longer creep

Texture weakening by dynamic recrystallization (DRX) control has been a challenging issue on improving the mechanical performance of wrought Mg alloys. Here we report the attainment of bi-directional DRX in an AZ31-0.9Nd-0.3Y alloy, which accelerated DRX and weakened the basal texture. The nature and content of secondary phase particles in the solidification microstructures were modified by the mixed-addition

Surface effects were investigated using ultrathin specimens with thicknesses in the order of the grain size of the material. The candidate material was a polycrystalline Ni-based superalloy (Alloy 718) purposely heat treated to document both the effects of the grain size and the metallurgical state, i.e., solid solution and precipitation hardened state, on the polycrystalline-to-multicrystalline behavior

The ratcheting behavior of plastic deformation accumulation under asymmetric loading poses significant risks to the safe service of engineering structures. For accurate prediction of the ratcheting behavior of the material, a physics-informed multimodal network named Dual Stream GRU (DSGRU) model is proposed with training and validation of 316LN stainless steel samples. By incorporating the unrecoverable

A new crystal plasticity finite element (CPFE) approach is developed to predict the mechanical behavior and ductility limits of thin metal sheets. Within this approach, a representative volume element (RVE) is chosen to accurately capture the mechanical characteristics of these metal sheets. This approach uses the periodic homogenization multiscale scheme to ensure the transition between the RVE and

Complex concentrated alloys (CCAs) differ from pure metals and conventional dilute alloys in that the multiple constituent elements are prone to develop special local atomic environments (LAEs). Due to the complexity and spatial variability of the LAEs, the resistance that they offer to travelling dislocations cannot be determined a priori by conventional strengthening theories. In this work, molecular

This research presents a dislocation-based hot deformation model to address a nickel-based superalloy's flow stress response and discontinuous dynamic recrystallization (DDRX) behavior. The developed model can predict the flow curves and subsequent microstructure evolutions during the hot deformation. The evolution of microstructure-reliant internal variables was predicted and validated thoroughly

In high-purity polycrystalline metallic materials, voids tend to favor grain boundaries as nucleation sites due to the elevated stress states produced by granular interactions and the weakened grain boundary from the relative atomic disorder. To quantify the key factors of this elevated stress state, simple compression of a small multi-grain cylinder of body-centered cubic tantalum was simulated using

Microcracking is a prevalent and critical issue in additively manufactured tungsten, significantly restricting its safety-critical engineering applications. Till now, most of our current knowledge about microcracking is based on the observation after additive manufacturing (AM) processing, the real-time evolution of microcracking is still largely unexplored, which is challenged by the complex multi-physics

High-strength low-alloy (HSLA) steels demonstrate superior strength and load-bearing capacity compared to traditional plain carbon steel. However, these steels are susceptible to microstructural damage even at intermediate strain rates, which can compromise their performance in automotive application. This research aims to investigate the stress-strain response, internal temperature rise, and damage

In this work, using a mesoscale model, we investigate void growth as mediated by plastic slip at face-centered cubic (FCC)/body centered cubic (BCC) phase boundaries. We employ a large-strain elasto-visco-plastic fast Fourier transform (LS-EVP-FFT) crystal plasticity model with the advantage of treating smooth conformal void surfaces in a crystal. The calculations aim to identify the role of crystallographic

Laser powder bed fusion (L-PBF) induces cellular structures that are considered significant contributors to the enhancement of strength and plasticity. However, after conducting fatigue crack growth (FCG) rate tests on L-PBF fabricated tantalum (LPBF-Ta), we found that cellular structures with specific growth directions can abnormally induce local brittle intergranular cracking, indicating that cellular

To control the curvature of yield loci, a generalized anisotropic distortional hardening ADH (G-ADH) model is established within the framework for Bauschinger effect prediction in ADH2022 (Hu and Yoon, 2022). Any yield criterion can be coupled with G-ADH. The convexity of G-ADH depends on the convexity of the coupled yield criterion. Under the proportional loadings, G-ADH still possesses the characteristics

Recycled Al-Cu alloys deteriorated mechanical properties due to stress concentration caused by coarse Fe-rich intermetallic (Fe-rich phases). This study aims to comparative analysis of processing technology of ultrasonic melt processing (USMP) or/and Al-Ti-B on microstructure and deformation behavior of Al-Cu alloys. They were investigated using various microscopy technique, such as, scanning/transmission

Two-phase nanolaminates are well-renowned for achieving extraordinarily high strengths but at the sacrifice of reduced toughness and strain to failure. Recently ”thick” interfaces, or so called 3D interfaces, in Cu/Nb nanolaminates were experimentally shown to improve both of these mechanical properties. In this work, we study the effect of 3D interfaces in the hexagonal close packed (HCP)/body centered

Primary hot working, represented by multi-directional hot forging and annealing, is a crucial step in microstructure control and plays a decisive role in the ultimate performance of ultra-high strength titanium alloy components. However, the interaction mechanisms of multiple physical processes comprising work hardening, dynamic recovery, dynamic recrystallization and grain fragmentation under complex