| Aspect | FCC (Face-Centered Cubic) | BCC (Body-Centered Cubic) |
|---|---|---|
| Crystal Structure | Atoms are arranged in a face-centered cubic structure, with atoms at each corner and the center of each face. | Atoms are positioned at the corners of a cube with a single atom at the center. |
| Atomic Packing Factor (APF) | 0.74, making FCC more densely packed and allowing better plasticity. | 0.68, less densely packed than FCC, leading to different mechanical properties. |
| Slip Systems | 12 slip systems, enabling greater ductility and better plastic deformation. | 48 slip systems, but typically fewer are active at low temperatures, resulting in less ductility compared to FCC. |
| Elastic Moduli | Higher Young’s modulus, making FCC structures stiffer and more resistant to elastic deformation. | Lower Young’s modulus compared to FCC, resulting in higher elasticity and ductility at low temperatures. |
| Ductility | FCC materials, like aluminum, copper, and austenitic steels, are generally more ductile and can undergo significant plastic deformation. | BCC materials, such as ferritic steels and refractory metals, are less ductile but have higher yield strengths at elevated temperatures. |
| Thermal Properties | FCC metals typically have higher thermal conductivity due to their dense atomic arrangement. | BCC metals generally exhibit lower thermal conductivity. |
| Impact on Metallic Glasses | FCC-like structures in metallic glasses tend to increase glass-forming ability and improve mechanical resilience. | BCC structures, when forming, can contribute to increased brittleness and lower glass-forming ability in metallic glasses. |
| Stress-Strain Behavior | Exhibits higher strain hardening due to the multiple active slip systems, resulting in better workability in processes like rolling. | More prone to brittle fracture under certain conditions due to fewer active slip systems. |
| Applications | Used in ductile metals such as aluminum, copper, and austenitic stainless steels. | Preferred for applications requiring strength at high temperatures, such as in ferritic steels and refractory metals. |
Improved elastic properties in FCC structures often contribute to their selection for applications requiring a balance between strength and ductility.