MSE Test2

more than one phase

one phase

a physically and chemically destinct material region

both elements have same crystal structure, similar electro neg, and atomic radii

2 components

complete solubility of one component in another

liquid transforms into two solid phases

solid phase tranforms into two different solid phases

• liguid and one solid phase transform into another solid phase
• L + S1 to S2

soft/ductile

strong/brittle

• hyper > .76% C
• hypo < .76% C

reversible

permanent

σ = F_t/A₀

T = F_s/A₀

a form of shear stress

• force in 4 directions
• ex. pressurized tank

force is same in all directions

ε = δ/L₀

ε_L = −δ _L/W₀

γ = Δx/y = tanθ

σ = E ε

E

σ_T = F/A_i

ε_T = ln (L_i/L_o)

• Energy needed to break a unit volume of material
• hammer test in lab

the plastic strain at failure

• Accompanied by significant plastic deformation
• one piece, large deformation

• little or no plastic deformation
• many Pieces
• small deformations

between grains

through grains

failure under applied cyclical stress

strain vs time 

• plane on which easiest slippage occurs
• highest planar density

• Direction of easiest slip movement
• highest linear density

same properties in all directions

properties depends on direction

• reduce grain size
• form solid solution
• -remove defects
• Percipitation strengthening
• -put different material in such as ceramic to combat shear strain
• Cold work
• -strain hardening
• -room temp
• -cold forming reduces cross sectional area

• Recovery
• -reduction of disolacation density by annihilation
• -atoms diffuse to form perfect atomic planes
• Recrystalization
• -new grains formed with lower dislocation density
• Grain grown
• -change grain size based on rate of cooling

deformation below T_R

Deformation above T_R

• small = strong and tough at low temps
• large = good creap resistance at high temps

Force needed for plastic deformation is much smaller than the force needed to break allbonds within the slip plane. This is where dislocations play a significant role to explain thisobservation. To cause large movement in the slip plane is not necessary to break all bonds ofthe particular plane but rather involve large number of dislocations or you can think of aspropagation of a dislocation.

recrystallization temperature = temperature at which recrystallization just reaches completion in 1 h.