2011 HL Section B question 4 (Thermal Equilibrium Diagram) Flashcards
Explain allotropy
the property of some chemical elements to take 2 or more different forms
Explain interstitial solid solution
Parent metal atoms are bigger than atoms of alloying metal
smaller atoms fit into spaces between larger atoms
difference between amorphous and crystalline structures
Amorphous structures have no pattern
crystalline structures have a pattern
Discuss the degree of brittleness in body centered cubic structures (bcc) and the degree of brittleness in face centred cubic structures (fcc)
The bcc structure has an atom in the center and an atom in the corner of the cube which makes it brittle
in the the fcc structure the atoms are tightly packed, making it tougher
Outline the various stages of solidification as a metal cools
As the metal reaches cooling point small particles cool first
solidification takes place in a pattern called dentrithic growth
each small particles grows to form a crystal or a grain
crystals grow together to form a solid