Ceramics Reading Assignment
Spring 2005
CEMM 260
1. Crystal structures and Ionic packing
a. Chapter 2, Section 2.2 pp 31-43, especially Table 2.1 p 38
b. Chapter 3, section 3.3 pp 73-76, especially
Figure 3.8, p 73, CsCl structure
Figure 3.9,p 74, NaCl structure – octahedral coordination
Tetrahedral coordination – Figure 2.19, p 46
Figure 2.16 p 46 Diamond cubic structure
Figure 2.17, p 46, SiO4 4- ions
Figure 3.23, p 87 Diamond cubic structure
Figure 3.24, p 87, Zincblende structure
Figure 3.11, p76, Cristobalite (SiO2)
2. Figure 12.1,p 440, elements in earth’s crust, Note Si, O, Al
3. Melting of tetrahedral coordinated ionic structures is gradual because of the
strength of the Si-O bond. SiO4 4- ions stay together in the liquid state. Slow
diffusion and viscous liquid Figure 6.42,p234. Easy to make glass Figure 4.23,
page 139 and Figure 6.40 page 233. Short range order, but no long range order.
All O2- ions are shared between two SiO4 4- tetrahedral group ions.
4. Glass: Section 4.5,pages 139-141. Section 12.2 pages 444- 447. Vitreous silica
is very high melting, needs very high T to work. Lower softening temperature by
adding network modifiers: Oxides with larger cations that have higher
coordination numbers and weaker bonds between the cation and O2- ions.
Network modifiers contribute O2- ions to the network, breaking it up and making
softening T lower. See Figure 4.25, p 141. Soda Lime glass contains CaO and
Na2O as network modifiers, used for container glass and window glass (Table
12.4). Catch with network modifiers is that the raise the thermal expansion
coefficient (CTE) of the glass. See Table 7.2, page 255. Higher CTE of soda
lime glass (9.0) compared with vitreous silica (0.5) means that soda lime glass is
more susceptible to thermal shock. You can get around this to some extent by
using low melting network former in the mixture, like B2O3, borosilicate glass,
Pyrex TM. Other network modifiers are K, Mg, Pb. PbO is especially in optical
glass for high index of refraction. See page 599, bottom. Also PbO or BaO for
radiation shielding in CRT monitors.
5. Mechanical Properties: Always brittle fracture page 202-206
a. Flexure strength. Usually measure Modulus of Rupture (MOR) in flexure
test Fig 6.4, equation 6.10, p 203. Fracture grows from flaw on side in
tension.
b. Fracture Mechanic, strength of brittle material depends on flaw size,
largest flaw in surface limits strength, see sample problem 6.4 p 205, and
sample problem 8.3, page 279
c. Variability of Properties Because of distribution of flaw sizes, ceramics
will have a higher distribution of strengths than metals. Need to
characterize both the MOR and the standard distribution of MOR for
design purposes. The same ceramic may have different properties
depending on processing.
d. Tempered glass. Uses residual compressive stresses on surface Figure
6.43,page 235, Safety glass, pages 237-238.
6. Cement: hydrated calcium silicates. Tables 14.6 and 14.7 p 514
Homework problems 6.15, 6.17, 9.40, 12.2, 12.7