Final answer:
Ferrite and austenite are allotropes of iron with different crystal structures and properties. Ferrite has a body-centered cubic structure and is stable at lower temperatures, while austenite has a face-centered cubic structure and is stable at higher temperatures.
Step-by-step explanation:
Ferrite (alpha phase) and austenite (gamma phase) are both allotropes of iron that exist at different temperatures. Ferrite is the stable phase of iron at temperatures below 912 degrees Celsius, while austenite is the stable phase at higher temperatures.
The main difference between ferrite and austenite lies in their crystal structures. Ferrite has a body-centered cubic (BCC) crystal structure, which means that iron atoms are arranged at the corners and in the center of each cube. Austenite, on the other hand, has a face-centered cubic (FCC) crystal structure, where iron atoms are located at the corners and in the center of each face of the cube.
The crystal structures of ferrite and austenite give them different properties. Ferrite is relatively soft and ductile, while austenite is harder and less ductile. Additionally, austenite has a higher solubility for carbon, which enhances its strength and hardness compared to ferrite.