Point Defects (Leaving Cert Engineering): Quizzes
📚Quizzes
Practise the questions
12 questions from this quiz
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Practise the questions
12 questions from this quiz
What are crystal lattice structures in metals?
What are crystal lattice structures in metals?
Organised arrangements of atoms
What are point defects in crystalline materials?
What are point defects in crystalline materials?
Imperfections at individual atomic sites
Why are point defects called zero-dimensional?
Why are point defects called zero-dimensional?
They occur at specific atomic positions
What is a vacancy defect?
What is a vacancy defect?
Atoms absent from expected positions
How does surrounding material respond to vacancy defects?
How does surrounding material respond to vacancy defects?
Distorts inward
When do vacancy defects commonly occur?
When do vacancy defects commonly occur?
During cooling after metal forming
What are substitution defects?
What are substitution defects?
Foreign atoms replacing parent atoms
What effect do larger foreign atoms have in substitution defects?
What effect do larger foreign atoms have in substitution defects?
Create compressive stress
What effect do smaller foreign atoms have in substitution defects?
What effect do smaller foreign atoms have in substitution defects?
Generate tensile stress
What are interstitial defects?
What are interstitial defects?
Foreign atoms between normal positions
Why are interstitial defects generally undesirable?
Why are interstitial defects generally undesirable?
They reduce ductility and increase stress
What happens when defect concentrations are high?
What happens when defect concentrations are high?
Unpredictable mechanical properties