Metal Defects (Leaving Cert Engineering): Flashcards
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13 cards from this deck
Crystal lattice structures
Crystal lattice structures
Organised arrangements of atoms in metals
Defects in metals
Defects in metals
Structural imperfections in crystal structures
Point defects
Point defects
Imperfections at individual atomic positions in lattice
Dimension of point defects
Dimension of point defects
Zero-dimensional (occur at specific atomic positions)
Properties affected by point defects
Properties affected by point defects
Strength, hardness, and ductility
Vacancy defects
Vacancy defects
Atoms absent from expected positions in crystal lattice
Effect of vacancy defects on surroundings
Effect of vacancy defects on surroundings
Surrounding material distorts inward
Substitution defects
Substitution defects
Foreign atoms replace parent atoms in lattice positions
Effect of larger foreign atoms
Effect of larger foreign atoms
Create compressive stress in surrounding lattice
Effect of smaller foreign atoms
Effect of smaller foreign atoms
Generate tensile stress in surrounding lattice
Interstitial defects
Interstitial defects
Foreign atoms occupy spaces between normal atomic positions
Effects of interstitial defects
Effects of interstitial defects
Increase hardness, reduce ductility, increase brittleness
High defect concentrations cause
High defect concentrations cause
Unpredictable mechanical properties