Introduction to Ceramics

Ceramics

• Ceramics are derived from the Greek words "keramos" (potter's clay) and "keramikos" (clay products).
• Traditional ceramics include whiteware, tiles, bricks, and sewer pipes.
• Industrial ceramics are used in engineering, high-tech, turbine, automotive, and aerospace components.
• Raw materials for ceramics include clay (fine-grained, sheet-like structure), kaolinite (from Kaoling hill in China), alumina (aluminum oxide), zirconia (zirconium oxide), carbides (cutting tools), nitrides, sialon (derived from Si, Al, O2, N2,), and cermets (black or hot-pressed ceramics).
• Ceramics are composed of silicates.
• Ceramics exhibit brittleness which is a property of strength and hardness.
• Glass is an amorphous solid with a structure like a liquid.
• Supercooled ceramics are cooled too quickly to form crystals, resulting in a non-crystalline structure.
• Ceramics are fabricated by heating materials to a molten or viscous state to produce useful items.
• Glass ceramics have a predominantly crystalline structure and desirable properties superior to glass.

Graphite

• Graphite is a crystalline form of carbon with a layered structure.
• The layers in graphite are bonded by weak forces allowing them to slide over each other.
• Basal planes are distinct layers in graphite.
• Diamond is another form of carbon with a covalently bonded structure.

Composites

• Composites are a combination of two or more chemically distinct materials.
• 4000 BCE, straw and clay were used to create bricks for construction.
• 1800s, steel reinforcing rods were combined with concrete for reinforced concrete structures.
• Reinforced plastics, also known as polymer matrix composites, comprise of a polymer matrix and reinforcing fibers.

Reinforced Plastics

• Hybrid materials involve more than one type of composite.
• Reinforcing fibers have high specific strength.
• The plastic matrix is less strong and less stiff.
• E-type glass is the most commonly used calcium aluminoborosilicate glass.
• S-type glass offers higher strength and stiffness but at higher cost.
• E-CR type glass exhibits higher resistance to elevated temperatures and acids.

Polymer Fibers

• Polymer fibers may contain nylon, rayon, acrylics, or aramids.
• Spectra is an ultra-high molecular weight fiber.
• Melt spinning involves extruding liquid polymer through holes in a die.
• Dry spinning involves dissolving the polymer into a liquid solution which creates a partially oriented liquid crystal form.
• Polymers can be fabricated into short or long fibers.

Carbon Fibers

• Carbon fibers are more expensive than glass fibers.
• Graphite fibers enhance electrical and thermal conductivity of reinforced plastic components.
• Ceramic fibers have low elongation, low thermal conductivity, and good chemical resistance.

Explore the fascinating world of ceramics, including their history, types, and raw materials used in their production. This quiz covers topics from traditional ceramics like tiles and bricks to advanced industrial applications in various fields. Test your knowledge on the properties and fabrication processes of ceramics and glass!