MATERIALS CLASSIFICATION

MATERIALS CLASSIFICATION

1. METALS & ALLOYS

   • - Properties: High electrical conductivity, good formability, castable, machinable, vibration-damping, significantly strengthened by heat treatment. - - Characteristics: High strength, high stiffness, ductility or form ability, and shock resistance.
     • Examples: Steels, aluminum, magnesium, zinc, cast iron, titanium, copper, and nickel.

2. CERAMICS & GLASSES

   • - Properties: Optically transparent, thermally insulating, refractive index, low optical losses, high ability to store charge, withstand high temperatures, relatively inert to molten metal. - Characteristics: Low to moderate density compared to metals, stiffness, good strength retention at elevated temperatures, resistant to high temperature creep.
     • Examples: Barium titanate, silica.

3. POLYMERS

   • - Properties: Easily formed into thin, flexible, airtight film, electrically insulating and moisture-resistant, strong. - Characteristics: Good electrical and thermal insulators, typically not suitable for use at high temperatures, good resistance to corrosive chemicals, good ductility, brittle and formability.
     • Examples: Polyethylene, epoxy, phenolics.

4. SEMICONDUCTORS

   • - Properties: Unique electrical behavior, converts electrical signals to light, lasers, laser diodes, etc. - Characteristics: The electrical conductivity of semiconducting materials is between that of ceramic insulators and metallic conductors.
     • Examples: Silicon, germanium, and gallium arsenide-based semicon- ductors

5. COMPOSITES

   • - Properties: High strength-to-weight ratio, high hardness, yet good shock resistance, low cost and high strength of steel with the corrosion resistance of titanium. - Characteristics: Lightweight, strong, ductile, temperature-resistant materials.
     • Examples: Concrete, plywood, and fiberglass.