Material Exam 1 Study Guide (GPT)

Metals

Strong, Ductile, Conductive, Crystalline Structure

Ceramics

Hard, Brittle, High Melting Point, Insulating

Polymers

Lightweight, Flexible, Low Strength, Poor Conductivity

Composites

Combination of Materials for Tailored Properties

Mechanical

Strength, Toughness, Hardness, Ductility

Thermal

Melting Point, Thermal Conductivity, Expansion

Electrical

Conductivity, Resistivity

Economic

Cost, Availability, Ease of Processing

Environmental

Corrosion Resistance, Recyclability

Ionic Bond

Ceramics

Covalent Bond

Ceramics/Polymers

Metallic Bond

Metals

Van der Waals

Polymers

Unit Cell

Smallest Repeating Structure

BCC

Body Centered Cubic: Stronger, Less Ductile

FCC

Face-Centered Cubic: Ductile, Close-Packed

HCP

Hexagonal Close-Packed: Strong, Limited Slip

Equation for Desnity

p=(nA)/(Vc*Na)

Elastic Region

Stress Strain (Hooke’s Law)

Yield Point

Plastic Deformation Begins

Ultimate Tensile Strength (UTS)

Max Stress Material Withstands

Fracture Point

Failure

Toughness

Area Under Curve

Elastic Modulus (E)

Stiffness

Ductility

% elongation or % reduction area

Toughness

Energy Absorbed Before Fracture

Hardness

Resistance to Indentation

Elastic

Reversible (Returns to Original Shape)

Plastic

Permanent Deformation (Atoms Slip Past Each Other)

Dislocations

Line Defects in Crystals

Dislocation Motion

Main Mechanism of Plastic Deformation

Grain Size Reduction

Smaller Grains = Stronger

Solid Solution Strengthening

Impurities Hinder Dislocation Motion

Strain Hardening (Work Hardening)

Plastic Deformation Increases Strength

Precipitation Hardening

Small Particles Block Dislocations

Cold Working

Increases Dislocation Density: Stronger but less Ductile