How Texture Forms: A Few Basic Core Metallurgical Mechanisms
Deformation textures
During plastic deformation, grains rotate as slip (and in some structures, twinning) accommodates strain. Because slip systems are crystallographically constrained, certain orientations rotate
toward stable end states under a given strain path (plane strain rolling, uniaxial tension, simple shear). The outcome is a deformation texture, which depends on:
- Crystal structure and active slip/twin systems (fcc vs bcc vs hcp)
- Strain path and magnitude (rolling reductions, shear components)
- Temperature and strain rate (affecting dynamic recovery and cross slip)
- Initial texture (inheritance and path dependence)
In hcp alloys, deformation twinning can dominate texture evolution. Twins reorient parts of grains by specific crystallographic relationships, producing strong texture changes even at moderate
strains.
Recrystallization textures
Annealing after deformation leads to recovery and recrystallization. New strain-free grains form and grow, often exhibiting textures different from the deformation state. Recrystallization
texture is governed by nucleation and growth selection:
- Oriented nucleation: Certain orientations nucleate more readily in regions of high stored energy (e.g., shear bands) or at boundaries with favorable misorientations.
- Oriented growth: Even if many orientations nucleate, those with growth advantages (lower boundary energy or higher mobility) can dominate.
The balance between these effects depends on stacking fault energy (SFE), solute content, second-phase particles, and annealing conditions. In fcc alloys, Cube texture strengthening after
recrystallization is a classic case with major implications for aluminum sheet formability and surface appearance.
Transformation textures
Phase transformations can generate texture through orientation relationships (ORs) between parent and product phases. Examples include:
- Austenite (fcc) → ferrite/martensite (bcc/bct) in steels: ORs such as Kurdjumov–Sachs or Nishiyama–Wassermann link parent and product orientations. The product texture is shaped by the parent texture plus variant selection (which variants are favored by stress state, transformation strain accommodation, or microstructural constraints).
- β (bcc) → α (hcp) in titanium alloys: Burgers OR controls inherited textures and leads to pronounced anisotropy depending on processing.
Transformation textures are particularly important in advanced high-strength steels (AHSS) and titanium alloys, where properties depend sensitively on phase morphology, variant selection, and
inherited orientation distributions.
Solidification textures
During casting and additive manufacturing, directional heat flow and competitive grain growth can cause columnar grains and strong textures (often fiber textures along build or thermal gradient
directions). These textures can be beneficial (directional properties) or detrimental (anisotropy, cracking susceptibility). In AM, texture couples strongly with melt pool geometry, scanning
strategy, and epitaxial growth from underlying layers.
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