Martensitic Phase Transformations in Metallic Alloys

Martensitic phase transformations are rapid, diffusionless solid–solid transitions in which a parent crystal lattice reconfigures by coordinated shear and atomic shuffles into a martensite lattice. This displacive mechanism yields characteristic plate‐like or lath microstructures with distinct orientation relationships and habit planes that govern transformation morphology. Common examples include the face‐centred cubic (fcc) to body‐centred cubic (bcc) or body‐centred tetragonal (bct) transitions in steel and nickel-titanium shape-memory alloys. The driving force arises from undercooling or applied stress, and the transformation proceeds via nucleation at defects, interfaces or free surfaces, followed by rapid interface propagation. Martensitic transformations underpin key engineering properties—high strength, toughness, hysteresis and shape-memory behaviour—and are tailored through alloy chemistry, thermo-mechanical treatments and nanoscale design to meet critical demands in aerospace, biomedical and cryogenic applications.

Research from Nature Portfolio

Recent studies have elucidated nanoscale mechanistic details of martensitic transformations in model alloy systems. In alloy nanoparticles, in situ heating transmission electron microscopy has revealed that the bcc phase nucleates preferentially at free-surface edges of fcc particles and propagates via a few-atoms-wide coherent fcc–bcc interface acting as a transient precursor. These observations furnish a framework for tuning interface structure to control transformation kinetics and mechanical response. In steels, a continuous crystallographic model has been developed for specific {225}γ habit planes, demonstrating that a balanced combination of twin-related variants within the Kurdjumov–Sachs orientation relationship reproduces classical phenomenological predictions while providing an explicit atomic pathway for the fcc–bcc transformation.

Martensitic Phase Transformations in Metallic Alloys publication trend

The graph below shows the total number of articles in martensitic phase transformations in metallic alloys across all publications each year (not limited to Nature Index journals).

Technical terms

Martensitic transformation: A diffusionless, shear-dominated phase change in which the lattice reconfigures by coordinated atomic displacement.

Austenite: The high-temperature face-centred cubic parent phase in steels and other alloys.

Martensite: The low-temperature body-centred cubic or tetragonal product phase formed by the martensitic transformation.

Bain path: A crystallographic description of lattice deformation transforming fcc to bcc by uniform strain.

Coherent interface: A boundary between phases with continuous lattice planes across the interface, minimising interfacial energy.

Habit plane: The undistorted crystallographic plane that lies approximately between parent and product phases during transformation.

Orientation relationship: A specific alignment between parent and martensite lattices, such as Kurdjumov–Sachs or Nishiyama–Wassermann.

References

1. Dynamics of the fcc-to-bcc phase transition in single-crystalline PdCu alloy nanoparticles. Nature Communications (2023).
2. {225}γ habit planes in martensitic steels: from the PTMC to a continuous model. Scientific Reports (2017).
3. Effect of C on the Martensitic Transformation in Fe-C Alloys in the Presence of Pre-Existing Defects: A Molecular Dynamics Study. Crystals (2019).
4. Interrogating the Effects of Hydrogen on the Behavior of Planar Deformation Bands in Austenitic Stainless Steel. Metallurgical and Materials Transactions A (2021).
5. α ↔ γ phase transformation in iron: comparative study of the influence of the interatomic interaction potential. Modelling and Simulation in Materials Science and Engineering (2020).