MTL 200 Lecture Notes - Lecture 2: Grain Boundary, Linear Density, Metal

• School: Ryerson University
• Department: Mechanical Engineering
• Course: MTL 200
• Professor: Eli Vandersluis

Document Summary

Mtl 200 chapter 3: the structures of crystalline solids. Fundamental concept: atoms in crystalline atoms are positioned in orderly and repeated pattern that are in contrast to the random and disordered atomic distribution found in non-crystalline or amorphous materials. Unit cells: crystal structures are specified in terms of parallelepiped unit cells, which are characterized by geometry and atom positions within. Unit cell edge length (a) and atomic radius (r) are related according to. Two features of a crystal structure are: coordination number the number of nearest-neighbor atoms, and, atomic packing factor the fraction of solid sphere volume in the unit cell. Density computations: the theoretical density of a metal () is a function of the number of equivalent atoms per unit cell, the atomic weight, unit cell volume, and avogadro"s number. Polymorphism is when a specific material can have more than one crystal structure.