A5047122351- Microstructure and mechanical properties
- Aluminum Alloys Composites Properties
- Advanced ceramic materials synthesis
- Metallurgy and Material Forming
- Solidification and crystal growth phenomena
- Additive Manufacturing and 3D Printing Technologies
- Geotechnical and Geomechanical Engineering
- Theoretical and Computational Physics
- MXene and MAX Phase Materials
- nanoparticles nucleation surface interactions
- Material Dynamics and Properties
- Advanced materials and composites
- High-Velocity Impact and Material Behavior
- Advanced Mathematical Modeling in Engineering
- Composite Material Mechanics
- Rock Mechanics and Modeling
- Tribology and Wear Analysis
- Rheology and Fluid Dynamics Studies
- Engineering and Environmental Studies
- Powder Metallurgy Techniques and Materials
- Aluminum Alloy Microstructure Properties
- Metallurgical Processes and Thermodynamics
- Granular flow and fluidized beds
- Metal and Thin Film Mechanics
- Titanium Alloys Microstructure and Properties
City University of Hong Kong
2022-2024
Shanghai Jiao Tong University
2020-2023
State Key Laboratory of Metal Matrix Composites
2022
We demonstrate that grain boundaries (GBs) behave as Brownian ratchets, exhibiting direction-dependent mobilities and unidirectional motion under oscillatory driving forces or cyclic thermal annealing. observed these phenomena for nearly all nonsymmetric GBs but not symmetric ones. Our observations build on molecular dynamics phase-field crystal simulations a wide range of GB types in both bicrystal polycrystalline microstructures. corroborate simulation results through situ experimental...
Grain rotation is commonly observed during the evolution of microstructures in polycrystalline materials different kinds, including metals, ceramics, and colloidal crystals. It widely accepted that interface migration these systems mediated by motion line defects with step dislocation character, i.e., disconnections. We propose a crystallography-respecting continuum model for arbitrarily curved grain boundaries or heterophase interfaces, accounting disconnections’ role rotation. Numerical...
Near-rigid-body grain rotation is commonly observed during growth, recrystallization, and plastic deformation in nanocrystalline materials. Despite decades of research, the dominant mechanisms underlying remain enigmatic. We present direct evidence that occurs through motion disconnections (line defects with step dislocation character) along boundaries platinum thin films. State-of-the-art situ four-dimensional scanning transmission electron microscopy (4D-STEM) observations reveal...
In this work, we investigate the shape evolution of rotated, embedded, initially cylindrical grains (with [001] cylinder axis) in Ni under an applied synthetic driving force via molecular dynamics simulations and a continuum, disconnection-based grain boundary migration model. For some initial misorientations, expanding form well-defined, faceted shapes, while for others shapes remain cylindrical. The embedded tend to rotate during migration, with direction rotation dependent on...
Grain growth describes the increase in mean grain size with time during annealing of a polycrystal; it is widely accepted that this driven by capillarity (surface tension). Although classically modeled and interpreted as curvature flow, growing body evidence has demonstrated overly simplistic inconsistent experimental observations. Despite many proposals for source failure, remains subject ongoing debate. By considering fundamental microscopic mechanism boundary (GB) migration, we...
Abstract: Excellent thermal conductivities of management materials are expected to ensure the timely heat dissipation in lots engineering applications and electronic devices. High in-plane conductivity laminated composites has become increasing significant for high energy power density In this study, continuous graphite film/aluminum (Gr film/Al) were fabricated by vacuum hot pressing. In-plane out-of-plane Gr film/Al tested. Two-dimensional structural models established, which volume...
Strength-toughness matching of particle reinforced metal matrix composites(PRMMCs) has become a key issue to meet the increasing requirements for their engineering applications in aerospace, defense, and transportation. Composite configuration (i.e. spatial distribution particles) can make effect on mechanical properties PRMMCs. In this work, high-throughput structural modeling simulations are performed indicate strength-toughness silicon carbide aluminum composites. Meanwhile, swarm...
Interface migration in microstructures is mediated by the motion of line defects with step and dislocation character, i.e., disconnections. We propose a continuum model for arbitrarily-curved grain boundaries or heterophase interfaces accounting disconnections' role rotation. Numerical simulations show that their densities evolve as size shape change, generating stresses increasing decreasing misorientation; predictions agree molecular dynamics pure capillarity-driven evolution, are...
An intrinsic feature of nearly all internal interfaces in crystalline systems (homo- and hetero-phase) is the presence disconnections (topological line defects constrained to interface that have both step dislocation character). Disconnections play a major role determining thermodynamics kinetics. We demonstrate elastic interactions between lead thermodynamic, first-order, finite-temperature, faceting-defaceting transition, agreement with experiments. These strongly modify equilibrium...