Flowchart for MSE301A: Phase Transformations—Interphases Interfaces Part 1

1. Interphase Interfaces in Solids

• Interface Definition
  • Change in system properties with distance
  • Area separating two homogeneous bulk phases
• Types of Interfaces
  • Solid-vapor Interfaces: Surfaces
  • Solid-Liquid Interfaces: Solidification
  • Solid-Solid Interfaces
    • Grain Boundaries
    • Interphase Interfaces

2. Types of Solid-Solid Interfaces

Grain Boundaries

• Boundaries between crystals of the same solid phase

Interphase Interfaces

• Boundaries between crystals of different solid phases
• Different crystal structures and/or compositions

3. Classification of Interphase Interfaces

Based on Atomic Structure

• Fully Coherent Interfaces
• Semicoherent Interfaces
• Incoherent Interfaces
• Complex Semicoherent Interfaces

4. Fully Coherent Interfaces

• Characteristics

  • Perfect matching at the interface plane
  • Continuous lattice across interface
  • Orientation relationship required

  An orientation relationship is a specific alignment of crystal structures between two different phases at their interface. It is necessary for fully coherent interfaces to maintain perfect atomic matching and continuous lattice across the boundary.

• Example

  • hcp silicon-rich κ phase and the fcc copper-rich α-matrix in Cu-Si alloys
  • Identical (111) and (0001) planes

• Strain-free Coherent Interfaces

  • Different chemical composition but same crystal structure

  

  • Different lattices