Electronic structure and atomic bonding determine microstructure and properties of ceramic and glass materials. What Are Ceramics? Just like in every material, the properties of ceramics are determined by the types of atoms present, the types of bonding between the atoms, and the way the atoms are packed together.

Ceramic composition and properties, atomic and molecular nature of ceramic materials and their resulting characteristics and performance in industrial applications. Industrial ceramics are commonly understood to be all industrially used materials that are inorganic, nonmetallic solids.

Ceramic Crystal Structures General considerations of structures for many (not all!) ceramics with ionic bonding –Anions (e.g., O2 -, F , Cl-) usually (but NOT always) larger than metal cations • Close packed anions in a lattice (usually FCC packing) • Cations fit …

• Structures of ceramic materials: How do they differ from those of metals? • Point defects: How are they different from those in metals? • Impurities: How are they accommodated in the lattice and how do they affect properties? • Mechanical Properties: What special provisions/tests are made for ceramic materials? Chapter 12: Structures &

How do the crystal structures of ceramic materials differ from those for metals? How do point defects in ceramics differ from those defects found in metals? How are impurities accommodated in the ceramic lattice? In what ways are ceramic phase diagrams different from …

Silicate ceramics Silicates are materials composed primarily of silicon and oxygen ( soils, rocks, clays, sand, and glass) Silica, silicon oxide (SiO 2), • Three crystal structures: quartz, cristobalite, and tridymite • Open structure, not close-packed, low density Si4+ O2-Adapted from Figs. 12.9-10, Callister 7e. crystobalite

• Structures of ceramic materials: How do they differ from those of metals? • Point defects: How are they different from those in metals? • Impurities: How are they accommodated in the lattice and how do they affect properties? • Mechanical Properties: What special provisions/tests are made for ceramic materials? Chapter 12: Structures &

Structures of ceramic materials: How do they differ from that of metals? Point defects: How are they different from those in metals? Impurities: How are they accommodated in the lattice and how do they affect properties? Mechanical Properties: What special provisions/tests are made for ceramic materials?

Chapter 12: Structures & Properties of Ceramics ISSUES TO ADDRESS... • Review of structures for ceramics • How are impurities accommodated in the ceramic lattice? • How are the mechanical properties of ceramics measured, and how do they differ from those for metals? • In what ways are ceramic phase diagrams similar to

Chapter 12: Structures of Ceramics Outline • Introduction • Crystal structures – Ceramic structure – AX-type crystal structures – A mX p-type – A mB nX p- type • Silicate ceramics • Carbon