Matse 259 Exam 2 UPDATED ACTUAL QUESTIONS AND CORRECT ANSWERS

Matse 259 Exam 2 UPDATED ACTUAL
QUESTIONS AND CORRECT ANSWERS
Resistence - CORRECT ANSWER Energy absorbed in elastic deformation



Toughness - CORRECT ANSWER Energy absorbed during fracture

-Includes resistance



True Stress Strain - CORRECT ANSWER -continually increasing

-uses current area, length (not originals)

-Metal gets stronger until fracture



Elastic recovery - CORRECT ANSWER Metal stretches during elastic deformation and shrinks
when force is removed



Hardness - CORRECT ANSWER surface resistance to plastic deformation

-relative hardness

-estimate UTS



Increasing temperature effects S-S - CORRECT ANSWER -Increases UTS

-increases Yield

-Decreases toughness

-increases Youngs modulus E

-decreases ductility



Increasing Strain Rate effects S-S - CORRECT ANSWER Opposite of Increasing temp

(same as decreasing temp)

Strain rate DOES NOT effect E



Linear Dislocation types - CORRECT ANSWER -edge

, -screw



Plastic deformation - CORRECT ANSWER -Atomic bonds break

-New bonds form



Atomic movement

Dislocation movement



Dislocation density - CORRECT ANSWER -new dislocation

-existing dislocation

-G.B. or P.B.

-interfacial defect



Strength and dislocation motion - CORRECT ANSWER The more mobility the weaker the part



Slip systems - CORRECT ANSWER -Slip plane

-slip direction

4planes x 3directions = 12 systems in FCC



Slip planes have the highest - CORRECT ANSWER atomic density



Slip directions have the highest - CORRECT ANSWER linear density



Resolved Shear Stress - CORRECT ANSWER τR = σ(cosλcosΦ)



τR - CORRECT ANSWER driving force of dislocation



τR (Max) - CORRECT ANSWER when λ = Φ = 45º



Single Crystals - CORRECT ANSWER -direct proof