Atomic Strusture And Thermal Properties Flashcards
What is specific heat capacity?
C is Q/(m deltaT)
What is the linear coefficient of thermal expansion?
Strain = linear coefficient of thermal expansion times deltaT
What is Fourier’s law?
Heat flux (q) = -k times temp gradient
What is thermal shock resistance?
TSR is proportional to (stress times k)/(E times linear coefficient of thermal expansion)
What are Valence electrons?
Outer shell electrons that determine the properties of the element
List the primary bonds and there benefits
Ionic, Covalent, Metallic. Provide high strength
What is ionic bonding?
Metal-Non metal, metal donates electron
What is covalent bonding?
Non metal- Non metal, share electrons
What is metallic bonding?
Metal-Metal, Valence electrons act as a dislocated sea of electrons
List the secondary bonds
Van der Waals, Hydrogen
What is Van der Waals bonding?
Attraction between opposite partial charges of neighbouring induced dipoles
What is hydrogen Bonding?
Interaction between hydrogen atoms and highly electronegative atoms (strong dipole-dipole attractions)
What is a unit cell?
Smallest repetitive volume which contains the complete lattice pattern of a crystal
What’s the equation for to find ‘a’ for a SC structure?
a=2r
What is the equation to find ‘a’ for a BCC structure?
a=4r/ root3
What is the equation to find ‘a’ for a FCC structure?
a=4r/ root2
What is the ideal c/a ratio?
1.633
Atomic packing factor
Volume of atoms in unit cell/ volume of unit cell
Density
nA/((Vc)(Na))
List the point defects
Vacancy atoms, interstitial atoms, substitutional atoms
What is vacancy atoms?
Atoms is missing in the lattice, causes distortion of planes
What is interstitial atoms?
Extra atom in the lattice, causes distortion of planes
What is substitutional atom?
Atoms in place of other atoms
List the line defects
Dislocations
