Topic Learning · Solid-State Transformations
Solid-State Transformations and Heat Treatment
Nine research cases from Nature-family papers use in-situ videos to make nucleation, interface migration, diffusion, precipitation, grain growth, and high-temperature oxidation visible as dynamic processes.
- Research Cases
- 9
- In-Situ Videos
- 10
- Learning Threads
- 3
Watch With Questions
- Why do phase transformations often nucleate near defects, grain boundaries, or triple junctions?
- How do diffusion, interface migration, and stress fields jointly determine microstructural evolution paths?
- How do annealing, precipitation, grain growth, and oxide-film formation affect final performance?
- What can in-situ TEM/STEM/ETEM, synchrotron methods, and dynamic microscopy each reveal?
Learning Map
From Transformation Mechanisms to Heat-Treatment Control
These videos are organized around the central storyline of microstructural evolution in materials processing: defects trigger nucleation, diffusion and interface migration drive growth, and surfaces and grain boundaries govern oxidation and degradation.
Diffusion, Precipitation, and Grain Growth
04 Cubic-to-hexagonal transformation in GST films: abnormal grain growth driven by surface energy
05 In-situ heating induced TiC monolayer growth: diffusion and 2D carbide formation
06 Ni nanoparticle exsolution and coarsening: migration, coalescence, and redissolution during annealing
07 Diamond nanoparticles moving into iron: interfacial diffusion and rigid-body migration in a carburization-like process
Oxidation and Surface Heat Treatment
Case Studies
In-Situ Observation Cases
Each case keeps its original paper and DOI so students can move from classroom phenomena to the source research.
01 · Nucleation and Interface Migration
Martensitic nucleation near dislocations: diffusive and diffusionless pathways are not always separate
The video turns phase-transformation nucleation into a real time sequence: defects, interface coherency, and local stress fields can redirect the nucleation pathway.
- Material System
- Model solid-solid transformation system
- Process
- Martensitic nucleation / solid-solid phase transition
- Characterization
- Dynamic microscopy / supplementary MOV
- Course Link
- TTT/CCT and martensitic transformation mechanisms
Source
Diffusive and martensitic nucleation kinetics in solid-solid transitions of colloidal crystals DOI: 10.1038/ncomms1497802 · Nucleation and Interface Migration
Temperature-driven ferroelastic domains: reversible martensitic transitions as actuation
A molecular-crystal case shows the coupling among temperature, moving phase boundaries, and shape change, clarifying how thermal paths alter microstructure and macroscopic response.
- Material System
- 1D hybrid perovskite molecular crystal
- Process
- Temperature-driven martensitic / thermoelastic transition
- Characterization
- Polarized optical microscopy / dynamic macroscopic observation
- Course Link
- Temperature-driven martensite / interface migration
Source
Near-room-temperature martensitic actuation profited from one-dimensional hybrid perovskite structure DOI: 10.1038/s41467-022-34356-903 · Nucleation and Interface Migration
α-to-ω transformation in zirconium: grain enlargement under room-temperature compression
Grain growth is not limited to high-temperature annealing; transformation driving force and stress state can also reshape grain scale.
- Material System
- Zr
- Process
- ω-phase grain nucleation and enlargement
- Characterization
- SXDM / Laue diffraction
- Course Link
- Grain growth
Source
Real time study of grain enlargement in zirconium under room-temperature compression across the α to ω phase transition DOI: 10.1038/s41598-019-51992-204 · Diffusion, Precipitation, and Grain Growth
Cubic-to-hexagonal transformation in GST films: abnormal grain growth driven by surface energy
The case links grain growth with phase stability, surface energy, and functional-device performance.
- Material System
- GST thin film
- Process
- Grain takeover / grain growth
- Characterization
- In-situ TEM
- Course Link
- Grain growth
Source
Surface Energy Driven Cubic-to-Hexagonal Grain Growth of Ge2Sb2Te5 Thin Film DOI: 10.1038/s41598-017-06426-205 · Diffusion, Precipitation, and Grain Growth
In-situ heating induced TiC monolayer growth: diffusion and 2D carbide formation
Heat treatment can activate the formation of new phases and interface structures, not only modify existing microstructures.
- Material System
- Ti3C2 / h-TiC
- Process
- In-situ heating / carbide growth dynamics
- Characterization
- In-situ STEM with ReaxFF/fbMC/MD-assisted interpretation
- Course Link
- Annealing / carbide formation
Source
In situ atomistic insight into the growth mechanisms of single layer 2D transition metal carbides DOI: 10.1038/s41467-018-04610-006 · Diffusion, Precipitation, and Grain Growth
Ni nanoparticle exsolution and coarsening: migration, coalescence, and redissolution during annealing
Atomic-scale video explains why precipitates grow, migrate, and lose stability, which is central to heat-treatment microstructure control.
- Material System
- Ni-doped SrTiO3 / exsolved Ni nanoparticles
- Process
- High-temperature annealing / exsolution / coarsening / redissolution
- Characterization
- In-situ STEM / SE / HAADF under high-temperature H2 or vacuum
- Course Link
- Annealing / precipitation coarsening
Source
Direct atomic-scale investigation of the coarsening mechanisms of exsolved catalytic Ni nanoparticles DOI: 10.1038/s41467-025-61971-z07 · Diffusion, Precipitation, and Grain Growth
Diamond nanoparticles moving into iron: interfacial diffusion and rigid-body migration in a carburization-like process
The case moves carburization and surface treatment beyond a macroscopic concentration-gradient picture toward interface diffusion channels and local stress driving forces.
- Material System
- Fe crystal / low-carbon steel with diamond nanoparticles
- Process
- High-temperature carbon diffusion / carburization-like surface treatment
- Characterization
- In-situ SEM/TEM heating observation
- Course Link
- Surface heat treatment / carburization-like process
Source
Inward motion of diamond nanoparticles inside an iron crystal DOI: 10.1038/s41467-024-48692-508 · Oxidation and Surface Heat Treatment
Facet effects in initial oxidation of Ni-5Cr: selective atomic filtering at metal/oxide interfaces
Initial oxidation is not a uniform coating process; facet and interface structures control elemental transport and protective-film formation.
- Material System
- Ni-5Cr alloy / oxide film
- Process
- High-temperature oxidation / surface passivation / oxide-film growth
- Characterization
- In-situ environmental TEM + DFT
- Course Link
- Surface heat treatment / in-situ thermal oxidation
Source
Selective atomic sieving across metaloxide interface for super-oxidation resistance DOI: 10.1038/s41467-024-50576-709 · Oxidation and Surface Heat Treatment
In-situ thermal oxidation at high-angle grain boundaries in Inconel 718: how grain-boundary energy shapes early oxidation
Grain boundaries are both fast diffusion paths and sensitive sites for oxidation damage; heat-treatment design must consider boundary character.
- Material System
- Inconel 718
- Process
- In-situ thermal oxidation at high-angle grain boundaries (20-800 °C)
- Characterization
- In-situ ETEM (environmental TEM)
- Course Link
- Oxidation
Source
Grain boundary energy affected initial oxidation on Ni-based superalloy revealed by in situ environmental TEM DOI: 10.1038/s41529-025-00705-4