What crystal lattice arrangement does alpha iron have ____________________?
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Answer: A. body centred cubic
Explanation
Alpha iron, commonly referred to as ferrite, is the stable allotrope of pure iron at room temperature and moderate heating. Its crystal lattice structure features atoms located at each of the eight cube corners and one single atom at the center. This body-centered cubic arrangement influences the mechanical ductility, magnetic properties, and slip systems of low-carbon steel. Crystal structures in metals change when heated or cooled past specific crystallographic transformation temperatures. Body-centered cubic crystal lattices typically exhibit a distinct ductile-to-brittle transition temperature at lower thermal ranges. Ferrite has a very low solid solubility limit for carbon compared to austenite due to the tight geometry of its interstitial sites.
Face-centered cubic describes the crystal lattice of gamma iron, known as austenite, which exists at elevated temperatures. Hexagonal close-packed is the crystal structure found in metals like titanium, magnesium, and zinc rather than alpha iron. Cubic structure and orthorhombic crystal terms are either overly broad or describe different mineral systems rather than ferrite.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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