Table of Contents
What is BCC FCC and HCP?
The hexagonal closest packed (hcp) has a coordination number of 12 and contains 6 atoms per unit cell. The face-centered cubic (fcc) has a coordination number of 12 and contains 4 atoms per unit cell. The body-centered cubic (bcc) has a coordination number of 8 and contains 2 atoms per unit cell.
Why the study of the crystal structure of metals is important?
A great example of the importance of crystal structure is the difference between two minerals; graphite and diamond. This shows us that it is not only important to know what elements are in the mineral, but it is also very important to know how those elements are stacked together.
How can you tell the difference between FCC BCC and HCP?
For example, FCC metals, Cu, Au, Ag, are usually soft and ‘ductile’, which means they can be bent and shaped easily. BCC metals are less ductile but stronger, eg iron, while HCP metals are usually brittle. Zinc is HCP and is difficult to bend without breaking, unlike copper.
What is FCC BCC?
BCC – Body Centred Cubic – and FCC – Face Centred Cubic – are descriptions of the arrangement of atoms in crystal structures. Most metal and alloys are crystalline, which means that their atoms arrange themselves in an ordered pattern.
What is BCC unit cell?
Body-centered cubic (BCC) is the name given to a type of atom arrangement found in nature. A body-centered cubic unit cell structure consists of atoms arranged in a cube where each corner of the cube shares an atom and with one atom positioned at the center.
What is a BCC structure?
What is the significance of unit cell in the formation of crystal structure?
A unit cell is the most basic and least volume consuming repeating structure of any solid. It is used to visually simplify the crystalline patterns solids arrange themselves in. When the unit cell repeats itself, the network is called a lattice.
Why are HCP metals more brittle?
Hexagonal close packed metals are typically more brittle than FCC and BCC metals because there are fewer slip systems in HCP.
Why are BCC metals brittle?
At high temperatures, FCC and BCC structured metals both have mobile dislocations, and thus they can sustain large plastic deformations without undergoing fracture. This lack of dislocation movement makes BCC brittle, while FCC stays ductile.