CHAPTER 19

THERMAL PROPERTIES

LEARNING OBJECTIVES

1. Define heat capacity and specific heat.

2. Note the primary means by which thermal energy is assimilated by solid

materials.

3. Define phonon.

4. Cite the equation for the low-temperature temperature dependence of heat

capacity at constant volume.

5. Define Debye temperature.

6. At temperatures in excess of the Debye temperature, cite the approximate

value for the constant volume heat capacity.

7. Determine the linear coefficient of thermal expansion given the length

alteration that accompanies a specified temperature change.

8. For an isotropic material, estimate the volume coefficient of thermal

expansion from the linear value.

9. Briefly explain the phenomenon of thermal expansion from an atomic

perspective using a potential energy-versus-interatomic separation plot.

10. Make a qualitative comparison of the coefficients of thermal expansion for

metals, ceramics, and polymers.

11. Define thermal conductivity.

12. (a) Note the two mechanisms of heat conduction.

(b) Compare the relative magnitudes of these contributions for each of

metals, ceramics, and polymeric materials.

13. (a) Determine the Wiedemann-Franz constant for a material at some

specified temperature, given values for its thermal and electrical

conductivities at this temperature.

(b) Briefly explain why values of this constant are virtually the same and

independent of temperature for all metallic materials.

14. For an isotropic solid material which ends are restrained by rigid supports,

calculate the thermal stress that results from a specified temperature change,

given values of the elastic modulus and coefficient of thermal expansion.

15. Explain the establishment of thermal stresses as a body of material is heated

or cooled.

16. Estimate the thermal shock parameter for a material given its fracture

strength, thermal conductivity, modulus of elasticity, and linear coefficient of

thermal expansion.